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1.
Vaccimonitor (La Habana, Print) ; 30(3)2021. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1341780

ABSTRACT

Contar con métodos diagnósticos que reúnan ciertos atributos es vital para guiar las decisiones sanitarias, el contexto actual lo amerita. Con el objetivo de validar la capacidad de dos pruebas rápidas para detectar anticuerpos debido a la infección por SARS-CoV-2 en la Isla de la Juventud, Cuba, de abril a mayo de 2020, se realizó un estudio descriptivo de corte transversal de evaluación de pruebas rápidas: Wondfo (SARS-CoV-2 antibody test) y Lungene covid-19 IgG/IgM rapid test, en comparación con la prueba de reacción en cadena de la polimerasa en tiempo real. Se construyeron dos muestras homogéneas de 250 cada una, determinándose indicadores de validación. Se obtuvieron valores de sensibilidad de 6,6 por ciento y 8,3 por ciento respectivamente para cada prueba, mientras que la especificidad resultó superior para Wondfo (95 por ciento). Los valores predictivos positivos resultaron muy bajos, los negativos adecuados, superior en Lungene con el 94,8 por ciento. Los valores de razón de verosimilitud fueron clasificados como inútiles. En diferentes escenarios en cuanto a casos sintomáticos, se alcanzó sensibilidad del 50 por ciento en intervalo de 1 a 7 días para Wondfo. El área bajo la curva ROC para Wondfo fue 0,50 (IC95 por ciento=0,46-0,55) y para Lungene 0,46 (IC95 por ciento=0,38-0,55). El índice kappa para Wondfo fue de 0,025 y 0,010 para Lungene. Las pruebas rápidas exploradas mostraron muy baja sensibilidad, valor predictivo positivo y razón de verosimilitud inadecuada. La validez global de las pruebas no demostró un buen desempeño diagnóstico, marcado por el valor del área bajo la curva ROC(AU)


Having diagnostic methods that meet certain attributes is vital to guide health decisions, the current context warrants it. In order to validate the capacity of two rapid tests to detect antibodies due to SARS-CoV-2 infection in Isla de la Juventud, Cuba, from April to May 2020, a descriptive cross-sectional evaluation study was carried out. Rapid tests: Wondfo (SARS-CoV-2 antibody test) and Lungene covid-19 IgG/IgM, were compared to the real-time polymerase chain reaction test. Two homogeneous samples of 250 each were constructed, determining validation indicators. Sensitivity values of 6.6 percent and 8.3 percent respectively were obtained for each test, while the specificity was higher for Wondfo (95 percent). The positive predictive values were very low, the negative ones were adequate, higher in Lungene with 94.8 percent. Likelihood ratio values were classified as useless. In different scenarios in terms of symptomatic cases, sensitivity of 50 percent was reached in an interval of 1 to 7 days for Wondfo. The area under the ROC curve for Wondfo was 0.50 (95 percent CI = 0.46-0.55) and 0.46 for Lungene (95 percent CI = 0.38-0.55). The kappa index for Wondfo was 0.025 and 0.010 for Lungene. The rapid tests explored showed very low sensitivity, positive predictive value, and inadequate likelihood ratio. The global validity of the tests did not demonstrate a good diagnostic performance, marked by the value of the area under the ROC curve. The degree of agreement was poor(AU)


Subject(s)
Humans , Validation Studies as Topic , COVID-19 Testing/methods , SARS-CoV-2 , COVID-19 , Enzyme-Linked Immunosorbent Assay/methods , Epidemiology, Descriptive , Cross-Sectional Studies , Cuba
2.
Vaccimonitor (La Habana, Print) ; 30(1)ene.-abr. 2021. tab
Article in English | LILACS, CUMED | ID: biblio-1150246

ABSTRACT

Foot and mouth disease is a highly contagious viral disease of cloven-hoofed animals that has a significant economic impact on livestock. A recent outbreak was detected and recorded as exotic strain of foot and mouth disease virus SAT2 (Serotype SAT2, topotype VII, Lib-12 lineage). The emergency vaccine was produced and assessed in vivo and large number of vaccine batches were urgently needed. The present work was aimed to provide a rapid evaluation of inactivated foot and mouth disease SAT2 oily vaccine to exclude the unsatisfactory batches during emergency circumstances and to reduce time, effort and cost. The extraction of foot and mouth disease antigen content from oily adjuvanted vaccine was carried out using isopropyl myristate and benzyl alcohol methods. The extracted viral antigen was identified by foot and mouse disease serotyping ELISA and 146S content was quantified using sucrose density gradient analysis. Evaluations were carried out instantly and at 2h, 6h and 24h. The results indicated the efficiency of benzyl alcohol to breakdown the oil emulsion either MONTANIDE™ ISA 206 VG or MONTANIDE™ ISA 50 V2, while the isopropyl myristate was efficient for MONTANIDE™ ISA 50 V2 only. The identification and quantification of 146S for extracted antigen using benzyl alcohol indicated significant stable records at different time intervals for the vaccine batches, while the extraction using isopropyl myristate indicated unstable records at different time intervals. It was concluded that the evaluation of monovalent foot and mouse disease vaccine could be conducted in vitro, using serotyping ELISA and quantification of 146S for the extracted antigen, either using benzyl alcohol or isopropyl myristate (MONTANIDE™ ISA50 V2 only), with the consideration that 146S content should not less than 4 μg/mL(AU)


La fiebre aftosa es una enfermedad viral altamente contagiosa de los animales de pezuña hendida que tiene un impacto económico significativo en el ganado. Se detectó un brote reciente que se registró como causado por una cepa exótica del virus de la fiebre aftosa (serotipo SAT2, topotipo VII, linaje Lib-12). La vacuna de emergencia se elaboró y evaluó in vivo, existiendo una urgente necesidad de contar con un gran número de lotes de la misma. El presente trabajo tuvo como objetivo proporcionar una evaluación rápida de la vacuna oleosa inactivada (SAT2) contra la fiebre aftosa, para excluir los lotes insatisfactorios durante circunstancias de emergencia, reduciendo tiempo, esfuerzo y costo. La extracción del contenido de antígeno de fiebre aftosa, de la vacuna oleosa adyuvada, se llevó a cabo utilizando miristato de isopropilo y alcohol bencílico. El antígeno viral extraído se identificó utilizando un ELISA de serotipificación y se cuantificó el contenido de 146S mediante análisis de gradiente de densidad de sacarosa. Las evaluaciones se realizaron de forma instantánea y a las 2h, 6h y 24h. Los resultados indicaron la eficacia del alcohol bencílico para separar la emulsión de aceite para MONTANIDE ™ ISA 206 VG o MONTANIDE™ ISA 50 V2, mientras que el miristato de isopropilo fue eficaz para MONTANIDE™ ISA 50 V2 únicamente(AU)


Subject(s)
Animals , Foot-and-Mouth Disease , Enzyme-Linked Immunosorbent Assay/methods , Vaccines
3.
Arq. bras. med. vet. zootec. (Online) ; 73(2): 293-301, Mar.-Apr. 2021. tab, graf, mapas
Article in English | LILACS, VETINDEX | ID: biblio-1248917

ABSTRACT

Mycoplasma bovis is a highly contagious agent associated with several pathologies in cattle. The detection of reactive antibodies to M. bovis by Indirect Enzyme-Linked Immunosorbent Assay (iELISA) identifies if there was an exposure to the microorganism. The current study aimed to optimize an iELISA from M. bovis total cell antigen, applying it to bovine serum samples, and to evaluate risk factors. Serum samples were obtained from 400 cows from 17 herds from Southeast Brazil. In the optimization of iELISA, the following was established: 2 µg/mL of antigen, sera dilution 1:300, and conjugate dilution 1:15000. The frequency was 62.3% (249/400) of reactive animals and 100% (17/17) of reactive herds. Risk factors were: herds with more than 100 animals (OR= 3.1; CI= 95%); Holstein breed (OR= 72.5; CI= 95%); cows (OR= 29.7; CI= 95%); intensive breeding system (OR= 3.3; CI= 95%); associated small ruminant production (OR= 4.4; CI= 95%); milk production above 500L (OR= 2.9; CI= 95%); no quarantine (OR= 1.5; CI= 95%); mechanical milking (OR= 5.5; CI= 95%) and cases of mastitis (OR= 5.5; CI= 95%). The proposed iELISA was able to detect antibodies reactive to M. bovis in bovine serum. Knowledge of these risk factors can assist in the implementation of prophylactic measures.(AU)


Mycoplasma bovis é um agente altamente contagioso relacionado a várias patologias em bovinos. A detecção de anticorpos reativos a M. bovis por Ensaio de Imunoadsorção Enzimática Indireto (iELISA) identifica se houve exposição ao microrganismo. O presente estudo teve como objetivo otimizar um iELISA de antígeno celular total de M. bovis, aplicando-o a amostras de soro bovino, bem como avaliar fatores de risco. Amostras de soro foram obtidas de 400 vacas de 17 rebanhos da Região Sudeste do Brasil. Na otimização do iELISA foram obtidos: 2µg/mL de antígeno, diluição dos soros 1:300 e do conjugado 1:15000. A frequência de animais reativos foi de 62,3% (249/400) e de 100% (17/17) para os rebanhos. Os fatores de risco foram: rebanhos com mais de 100 animais (OR= 3,1; IC= 95%); raça Holandesa (OR= 72,5;IC= 95%); vacas (OR= 29,7;IC= 95%); sistema intensivo (OR= 3,3; C= 95%); produção de pequenos ruminantes (OR= 4,4;IC=95%); produção de leite acima de 500L (OR= 2,9;IC= 95%); sem quarentena (OR= 1,5;IC= 95%); ordenha mecânica (OR= 5,5;IC= 95%) e casos de mastite (OR= 5,5;IC= 95%). O iELISA proposto foi capaz de detectar anticorpos reativos a M. bovis no soro bovino. O conhecimento desses fatores de risco pode auxiliar na implementação de medidas profiláticas.(AU)


Subject(s)
Animals , Female , Cattle , Mycoplasma bovis/isolation & purification , Mastitis, Bovine/complications , Mycoplasma Infections/diagnosis , Mycoplasma Infections/veterinary , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/veterinary , Risk Factors
4.
Gac. méd. Méx ; 157(1): 37-42, ene.-feb. 2021. tab
Article in Spanish | LILACS | ID: biblio-1279071

ABSTRACT

Resumen Introducción: La identificación de portadores del virus de la hepatitis B en donantes de sangre es imperativo para evitar la transmisión de la enfermedad a través de transfusiones sanguíneas. Objetivo: Determinar si los donantes de sangre con resultados positivos de los marcadores serológicos HbsAg y anti-HBc eran portadores de ADN del virus de la hepatitis B. Métodos: Se recolectaron 12 745 muestras de seis bancos de sangre ecuatorianos, las cuales fueron analizadas con pruebas serológicas para identificar los marcadores infecciosos HBsAg, anti-HBc, anti-HBs mediante prueba ELISA automatizada. Todas las muestras positivas para uno, dos o los tres marcadores fueron analizadas con técnica molecular para determinar la presencia de ADN viral. Resultados: Se identificó que 27.5 % de las muestras reactivas solo a anti-HBc y 100 % de las muestras con resultados positivos de HBsAg/anti-HBc-IgM/IgG presentaron ADN del virus de la hepatitis B (p = 0.001). Conclusiones: La elección de los marcadores de infección y los métodos de detección definen los resultados. Es importante la realización de dos pruebas serológicas y una molecular para identificar a los portadores del virus de la hepatitis B y evitar su transmisión.


Abstract Introduction: Identification of hepatitis B virus carriers in blood donors is imperative in order to avoid transmission of the disease via blood transfusion. Objective: To determine if blood donors with positive results for serological markers HBsAg and anti-HBc were hepatitis B virus DNA carriers. Methods: 12,745 samples were collected from six Ecuadorian blood banks and analyzed for HBsAg, anti-HBc and anti-HBs infectious markers by automated ELISA. All samples that tested positive for one, two or all three markers were analyzed with molecular techniques to determine the presence of viral DNA. Results: 27.5 % of the samples that were reactive for anti-HBc alone and 100 % of those with positive results for HbsAg and IgM/IgG anti-HBc were identified to contain hepatitis B virus DNA (p = 0.001). Conclusions: The selection of infection markers, as well as the detection methods define the results. Performing two serological and one molecular test is important in order to identify hepatitis B virus carriers and prevent its transmission.


Subject(s)
Humans , Blood Donors/statistics & numerical data , DNA, Viral/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Hepatitis B virus/genetics , Hepatitis B Surface Antigens/blood , Blood Banks , Enzyme-Linked Immunosorbent Assay/methods , Biomarkers/blood , Carrier State/diagnosis , Carrier State/virology , Hepatitis B virus/immunology , Ecuador
5.
Mem. Inst. Oswaldo Cruz ; 116: e200428, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154875

ABSTRACT

BACKGROUND Dogs are the main peridomiciliary reservoir of Leishmania infantum thus the correct diagnosis of infection is essential for the control of the transmission and treatment as well. However, the diagnosis is based on serological assays that are not fully effective. OBJECTIVE We aimed to establish an effective serological assay for the diagnosis of L. infantum infected dogs using Leishmania-derived recombinant antigens. METHODS Leishmania derived rK39-, rK28-, rKR95-based enzyme-linked immunosorbent assay (ELISA) was standardized using symptomatic and asymptomatic L. infantum-infected dogs. Then 2,530 samples from inquiry in endemic areas for VL were evaluated and the results compared with recommended assays by the Brazilian Ministry of Health (MH algorithm). Further samples from a cohort of 30 dogs were searched. FINDINGS For rK39-, rK28- and rKR95-ELISA the sensitivity was around 97% and specificity 100%. The positivity of these three ELISA in the inquiry samples was 27-28%, around 10% higher than the assays currently in use. When cohort samples were searched, we observed likely false-negative results (> 65%) with supposedly negative samples that turned positive six months later with the assays in use (MH algorithm). MAIN CONCLUSIONS For the diagnosis of L. infantum-infected dogs, rK39-based ELISA showed better diagnostic performance than other assays in use in Brazil and worldwide.


Subject(s)
Animals , Dogs , Enzyme-Linked Immunosorbent Assay/standards , Enzyme-Linked Immunosorbent Assay/veterinary , Antibodies, Protozoan/blood , Leishmania infantum/immunology , Dog Diseases/diagnosis , Leishmaniasis, Visceral/diagnosis , Recombinant Proteins/immunology , Brazil , Enzyme-Linked Immunosorbent Assay/methods , Serologic Tests , Sensitivity and Specificity , Leishmania infantum/isolation & purification , Leishmaniasis, Visceral/blood , Leishmaniasis, Visceral/veterinary , Antigens, Protozoan/biosynthesis
6.
Pesqui. vet. bras ; 40(12): 977-984, Dec. 2020. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1155042

ABSTRACT

Enzootic bovine leukosis (EBL) is an infectious disease caused by bovine leukemia virus (BLV) that affects cattle worldwide. Agar gel immunodiffusion (AGID) was the reference test for EBL diagnosis for many years, but enzyme-linked immunosorbent assay (ELISA) showed higher sensitivity, was faster to perform, and resulted in an objective reading. However, the importation of ELISA kits is lengthy and expensive, and currently, no AGID kits are available in Brazil. The aim of this work was to standardize an indirect ELISA (iELISA) for EBL diagnosis using BLV antigens produced in Tadarida brasiliensis lung (Tb1Lu) cells, which are Bovine viral diarrhea virus (BVDV) free, unlike fetal lamb kidney (FLK) cells, currently used for this purpose. Following standardization, iELISA results were compared with those obtained by AGID and the commercial Chekit Leucose-Serum ELISA. Compared to AGID, iELISA had 94,44% sensitivity, 75.68% specificity, 79.10% positive predictive value (PPV) and 93.30% negative predictive value (NPV), with 84% concordance and a Kappa index of 0.699. Compared to the Chekit Leucose-Serum ELISA, iELISA showed 92.60% sensitivity, 87.09% specificity, 90.27% PPV and 90,00% NPV, with 90.27% concordance and a Kappa index of 0.801. Taking into account the high agreement with the traditional tests and the absence of non-specific reactions with BVDV, the developed assay could be used as diagnostic method to control EBL in Brazil.(AU)


A leucose enzoótica bovina (LEB) é uma doença infecciosa natural dos bovinos com distribuição mundial causada pelo "bovine leukemia virus" (BLV). A imunodifusão em gel de ágar (IDGA) foi considerada por muitos anos o teste de eleição, porém ensaios imunoenzimáticos (ELISA) apresentam sensibilidade mais elevada e leitura mais rápida e objetiva. No entanto, a importação de kits de ELISA é um processo dispendioso e demorado, e atualmente não há kits de IDGA comercialmente disponíveis no Brasil. Desta forma, o objetivo deste trabalho foi padronizar um ELISA indireto (iELISA) para diagnóstico da LEB utilizando antígenos produzidos a partir do cultivo do BLV em linhagem celular Tadarida brasiliensis "lung" (Tb1Lu) livre de "bovine viral diarrhea virus" (BVDV), diferentemente do que acontece com as linhagens "fetal lamb kidney" (FLK) atualmente utilizadas na produção desses antígenos para uso em ensaios sorológicos. Após a padronização do iELISA, os resultados foram comparados com aqueles obtidos por IDGA e pelo ELISA comercial "Chekit Leucose-Serum". Comparado ao IDGA, o iELISA apresentou 94,44% de sensibilidade, 75,68% de especificidade, valor preditivo positivo (VPP) de 79,1% e valor preditivo negativo (VPN) de 93,3%, com concordância entre os testes de 84% e o índice Kappa 0,699. Quando comparado ao ELISA "Chekit Leucose-Serum", o iELISA apresentou sensibilidade de 92,6%, especificidade de 87,09%, VPP de 90,27% e VPN de 90%, com concordância de 90,27% e o índice Kappa 0,801. Portanto, devido à alta concordância com os testes tradicionais e ausência da ocorrência de reações inespecíficas com BVDV, o ensaio desenvolvido pode ser utilizado como ferramenta diagnóstica para o controle da LEB no Brasil.(AU)


Subject(s)
Animals , Cattle , Cattle/virology , Enzyme-Linked Immunosorbent Assay/methods , Enzootic Bovine Leukosis/diagnosis
7.
Acta bioquím. clín. latinoam ; 54(4): 395-406, jul. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1149029

ABSTRACT

Resumen El objetivo del presente trabajo fue el desarrollo de dos enzimoinmunoensayos competitivos (EIC) para la detección de trazas de soja y de leche en productos libres de gluten. Como anticuerpos primarios se utilizaron antisueros policlonales de conejo específicos contra proteínas de soja o de leche. Se determinaron las concentraciones óptimas de antígenos a inmovilizar en la placa y las concentraciones de anticuerpos primarios a utilizar en la competencia. Las curvas de calibración se ajustaron utilizando concentraciones crecientes de un extracto de producto de soja y de un extracto de leche descremada en polvo. El producto de soja y la leche descremada se extrajeron con buffer Tris-HCl 0,0625 M con dodecilsulfato de sodio al 3% y sulfito de sodio 0,1 M al 2%. Se evaluaron los parámetros de validación: linealidad, límites de detección y de cuantificación, recuperación y precisión en el día y entre días, los cuales resultaron adecuados. Se analizaron 9 productos libres de gluten con los EIC desarrollados y con kits de ELISA comerciales. Ambos EIC se comportaron de manera similar con respecto a los kits comerciales. Los EIC permitieron confirmar la presencia de leche en las muestras que la declaraban. En algunas muestras que no declaraban ni leche ni soja, ambos EIC detectaron su presencia (resultados confirmados con los kits comerciales). Los EIC desarrollados poseen menor costo que los kits y, por lo tanto, éstos podrían utilizarse como métodos de screening. Cuando esta metodología resulte negativa, debe confirmarse con un método más sensible (comercial) para garantizar la ausencia de proteínas de soja o de leche.


Abstract The aim of this study was to develop two competitive enzyme immunoassays (CEI) to detect the presence of traces of soy and milk in gluten-free products. Specific rabbit polyclonal antiserums against soy protein and other against elemilk protein were used as primary antibodies. Optimal antigen concentrations to be immobilized on the plate and primary antibody concentrations to be used in competition were determined. The calibration curves were fitted using increasing concentrations of an extract of soy product and of defatted milk powder. The soy product and the defatted milk were extracted with Tris-HCl buffer 0,0625 M with 3% sodium dodecyl sulfate and 2% sodium sulfite 0.1 M. The validation parameters were evaluated: linearity, limit of detection and quantification, recovery and precision on the day and in between days. They were appropriate. Nine commercial samples of gluten-free products were analyzed with these developed CEI and commercial ELISA kits. It was observed that both CEI behaved similarly with respect to the commercial kits. The enzyme immunoassays confirmed the presence of milk in samples that declared it. In some samples that did not declare the presence of milk or soy, both enzyme immunoassays detected their presence -these results were confirmed using commercial kits. The developed CEI have a lower cost than the commercial kits, so these could be used as screening methods. When this methodology is negative, it should be confirmed with a more sensitive (commercial) method to ensure the absence of soy or milk protein.


Resumo O objetivo do presente trabalho foi o desenvolvimento de dois enzimoimunoensaios competitivos (EIC), para a detecção de vestígios de soja e leite em produtos livres de glúten. Antissoros policlonais de coelho específicos contra proteínas de soja ou de leite foram utilizados como anticorpos primários. Foram determinadas as concentrações ótimas de antígenos a serem imobilizados na placa e as concentrações de anticorpos primários a serem utilizadas na competição. As curvas de calibração foram ajustadas usando concentrações crescentes de um extrato de produto de soja e de um extrato de leite em pó desnatado. O produto de soja e o leite desnatado foram extraídos com tampão Tris-HCl 0,0625 M com dodecil sulfato de sódio a 3% e sulfito de sódio 0,1 M a 2%. Os parâmetros de validação foram avaliados: linearidade, limite de detecção e quantificação, recuperação e precisão no dia e entre os dias, os quais resultaram adequados. Nove produtos livres de glúten foram analisados com os EIC desenvolvidos e com kits de ELISA comerciais. Os dois EICs se comportaram de maneira semelhante em relação aos kits comerciais. Os EIC permitiram confirmar a presença de leite nas amostras que o declararam. Em algumas amostras que declaravam nem leite nem soja, ambos os EIC detectaram sua presença (resultados confirmados usando kits comerciais). Os EIC desenvolvidos têm um custo menor que os kits, portanto, eles poderiam ser utilizados como métodos de triagem. Quando esta metodologia é negativa, deve ser confirmada com um método mais sensível (comercial) para garantir a ausência de proteínasda soja ou do leite.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Soybean Proteins/analysis , Diet, Gluten-Free , Food Analysis/methods , Milk Proteins/analysis , Sodium Dodecyl Sulfate , Enzyme-Linked Immunosorbent Assay/economics , Costs and Cost Analysis , Sodium Sulfite , Food Technology/methods
8.
Rev. cuba. hematol. inmunol. hemoter ; 36(2): e1115, abr.-jun. 2020. graf
Article in Spanish | LILACS, CUMED | ID: biblio-1149898

ABSTRACT

Introducción: En la supervivencia del corazón trasplantado son de importancia el empleo de los anticuerpos contra el sistema principal de histocompatibilidad (anticuerpos anti-HLA). Hace seis años se introdujo en Cuba el porcentaje de anticuerpos anti-HLA frente a panel (PRA) por método de ensayo de inmunoabsorción ligado a enzima (ELISA) como parte de las pruebas de compatibilidad pretrasplante de los receptores de trasplante cardiaco. Objetivo: Caracterizar los anticuerpos anti-HLA en pacientes receptores cubanos de trasplante cardiaco. Métodos: Entre septiembre de 2013 y abril de 2017 se les realizó el PRA por ELISA a 38 muestras de pacientes recibidas en el laboratorio de histocompatibilidad del Instituto de Hematología e Inmunología. Se utilizó la comparación de proporciones para el análisis estadístico. Resultados: El 47,4 por ciento de los pacientes estudiados presentó anticuerpos anti-HLA, fueron los más frecuentes los de clase I. La proporción de pacientes con PRA del 0 por ciento fue mayor en PRA clase II que en I (p: 0,0027). Mientras que fue mayor la proporción de pacientes con PRA clase I entre el 20 y el 75 por ciento (p: 0,0046). El 77,8 por ciento de los pacientes tuvo un PRA clase I mayor al 10 por ciento y en el PRA clase II alcanzó el 80 por ciento. Conclusiones: El porcentaje de anticuerpos anti-HLA frente a panel por método de ensayo de inmunoabsorción ligado a enzima permitió una mejor caracterización de los anticuerpos anti-HLA, lo que contribuyó a mejorar la compatibilidad en este tipo de paciente(AU)


Introduction: In survival after heart transplantation, the use of antibodies against the main histocompatibility system (anti-HLA antibodies) is important. Six years ago, the percentage of anti-HLA antibodies against panel (PRA) by enzyme-linked immunosorbent assay (ELISA) method was introduced in Cuba as part of the pre-transplant compatibility tests of heart transplant recipients. Objective: To characterize anti-HLA antibodies in Cuban heart transplant recipients. Methods: Between September 2013 and April 2017, PRA by ELISA was performed on 38 patient samples received in the histocompatibility laboratory of the Institute of Hematology and Immunology. Comparison of proportions was used for statistical analysis. Results: 47.4 percent of the study patients presented anti-HLA antibodies; those in class were the most frequent. The proportion of patients with PRA of 0 percent was higher in PRA class II than in class I (p=0.0027). The proportion of patients with PRA class I was greater, accounting for 20-75 percent (p=0.0046). 77.8 percent of the patients had a class I PRA greater than 10 percent, while in class II PRA it reached 80 percent. Conclusions: The percentage of anti-HLA antibodies versus a panel of enzyme linked immunosorbent assay method allowed better characterization of anti-HLA antibodies, which contributed to improving compatibility in this type of patient(AU)


Subject(s)
Humans , Heart Transplantation/methods , Transplant Recipients , Antibodies/therapeutic use , Enzyme-Linked Immunosorbent Assay/methods , Survival Analysis , Cuba
9.
Rev. cuba. med ; 59(1): e1337, ene.-mar. 2020. tab
Article in Spanish | LILACS, CUMED | ID: biblio-1139040

ABSTRACT

Introducción: Los biomarcadores son claves en el diagnóstico y pronóstico del lupus eritematoso sistémico en el cual las manifestaciones clínicas son extremadamente complejas y heterogéneas. Objetivo: Determinar el valor clínico de los inmunocomplejos circulantes en pacientes con lupus eritematosos sistémico. Métodos: Se determinaron los niveles séricos de inmunocomplejos fijadores del C1q y de los anticuerpos anti-ácido desoxirribonucleico de doble cadena (anti-ADNdc), anti-nucleosoma (anti-Nuc) y anti-proteínas ribosomales (anti-RibP) por el ensayo inmuno-adsorbente ligado a enzima (ELISA) en 93 pacientes con diagnóstico de lupus eritematosos sistémico. Se utilizaron exámenes no paramétricos para probar la asociación entre los inmunocomplejos y los auto-anticuerpos. La frecuencia de nefritis lupica en los grupos de pacientes positivos y negativos de inmunocomplejos circulantes se comparó mediante Chi cuadrado. Resultados: Los inmunocomplejos se encontraron en 24 (25,8 por ciento) pacientes con lupus eritematosos sistémico. Los pacientes que presentaron los títulos más altos de inmunocomplejos fueron los positivos a los tres auto-anticuerpos usados (p=0,044). Se encontró correlación directa entre los niveles de anti-RibP y los inmunocomplejos (Rho=0,303, p=0,003) y entre los anti-ADNdc y anti-Nuc (Rho=0,449, p=0,001). La nefritis lúpica se presentó en 58,3 por ciento de pacientes con inmunocomplejos, y 31,9 por ciento pacientes negativos de inmunocomplejos (p=0,213). Conclusiones: Los inmunocomplejos circulantes caracterizaron una fracción menor de pacientes con lupus eritematosos sistémico. La presencia de estos no se asoció a los anticuerpos anti-ADNdc ni a la nefritis lupica(AU)


Introduction: Biomarkers are essential in the diagnosis and prognosis of systemic erythematous lupus in which clinical manifestations are extremely complex and heterogeneous. Objective: To determine the clinical value of circulating immunocomplexes in patients with systemic erythematous lupus. Methods: Serum levels of C1q-binding immunocomplexes and anti-double-stranded deoxyribonucleic acid (anti-dsDNA), anti-nucleosome (anti-Nuc) and anti-ribosomal proteins (anti-RibP) were determined by enzyme-linked immunosorbent assay (ELISA) in 93 patients diagnosed with systemic lupus erythematosus. Nonparametric tests were used to test the association between immunocomplexes and auto-antibodies. The frequency of lupus nephritis in the circulating immunocomplex positive and negative patient groups was compared using Chi square. Results: Immunocomplexes were found in 24 (25.8 percent) patients with systemic lupus erythematosus. The patients with the highest immunocomplex titers were positive for the three autoantibodies used (p = 0.044). A direct correlation was found between the levels of anti-RibP and immunocomplexes (Rho = 0.303, p = 0.003) and between anti-dsDNA and anti-Nuc (Rho = 0.449, p = 0.001). Lupus nephritis occurred in 58.3 percent of immunocomplex patients, and 31.9 percent immunocomplex negative patients (p = 0.213). Conclusions: Circulating immunocomplexes characterized a smaller fraction of patients with systemic lupus erythematosus. Their presence was not associated with anti-dsDNA antibodies or lupus nephritis(AU)


Subject(s)
Humans , Male , Female , Enzyme-Linked Immunosorbent Assay/methods , Biomarkers, Tumor/analysis , Lupus Erythematosus, Systemic/diagnosis , Cross-Sectional Studies , ISCOMs/analysis
10.
Prensa méd. argent ; 106(1): 44-49, 20200000. tab
Article in English | LILACS, BINACIS | ID: biblio-1370439

ABSTRACT

Background: There was some trade produced enzyme-immuno-sorbent assays tests to diagnose antigens of Giardia spin stool specimens, like Rida Quick Giardia and Serazym ELISA Giardia® tests. In this study, we evaluated the performance of two commercially available EIA kits for detecting Giardia antigens. Methods: A total of 96 stool specimens were collected from patients who attended for different Primary Health Care centers in Al-Qurna sector / Basrah Health Directorate, Ministry of Health/ Environment, Basrah, Iraq at period from 2nd of March 2018 to 28th of September 2018. All specimens were examined by conventional methods of microscopic examination, and by both enzyme-immuno-sorbent assays tests. Results: Serazym ELISA Giardia® had a sensitivity of 90.1%, a specificity of 100%, and an accuracy of 91.7%. The Rida Quick Giardia® showed a sensitivity of 79%, a specificity of 100%, and an accuracy of 82.3%. Serazym ELISA Giardia® showed 10% discrepancy better than Rida Quick Giardia® which showed 8%, this was of a statistically significant difference (P<0.05). Conclusion: Antigen detection by EIA has been established as a valuable tool to make parasite stool diagnostics more effective. Serazym ELISA Giardia® is more reliable than Rida Quick Giardia


Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/methods , Giardiasis , Feces/parasitology , Giardia/parasitology , Antigens
11.
Arq. Inst. Biol ; 87: e0012020, 2020.
Article in English | LILACS, VETINDEX | ID: biblio-1130112

ABSTRACT

Caprine herpesvirus 1 (CpHV-1) infection is associated with clinical manifestations related to animal age, with high mortality in kids and infertility in adults. Given the scarcity of research about the epidemiological situation of this infection in Brazilian flocks, we aimed to conduct a cross-sectional descriptive study to detect antibodies against CpHV-1 in goats in the state of São Paulo, Brazil. Fifty-five male and female goats ­ kids and adult ­ were assessed in this study. Blood serum was analyzed by a commercial ELISA kit to detect antibodies against CpHV-1, which had not been used in Brazil before. No animals were reactive. Brazil lacks information about CpHV-1 infection in goat flocks. Continuing the study is crucial to understand the epidemiological situation of the disease and establish protocols for infection control.(AU)


A infecção pelo Herpesvírus Caprino tipo 1 (CpHv-1) está associada a manifestações clínicas relacionadas à idade dos animais, com alta mortalidade em filhotes e infertilidade em adultos. Diante da escassez de estudos sobre situação epidemiológica dessa infecção nos rebanhos brasileiros, a presente pesquisa teve como objetivo realizar um estudo transversal e descritivo para a detecção de anticorpos anti-Herpesvírus Caprino tipo 1 em caprinos do estado de São Paulo, Brasil. Foram avaliados 55 caprinos machos e fêmeas, filhotes e adultos. O soro sanguíneo foi analisado por um kit ELISA comercial para detecção de anticorpos contra CpHv-1, de utilização inédita no Brasil. Nenhum animal estudado foi sororreagente. O Brasil carece de informações acerca da infecção pelo Herpesvírus Caprino tipo 1 nos rebanhos caprinos do país. A continuidade do estudo é imprescindível para compreender a situação epidemiológica da enfermidade e estabelecer protocolos para controle da infecção.(AU)


Subject(s)
Animals , Male , Female , Peptides/immunology , Goats/virology , Glycoproteins/immunology , Varicellovirus/immunology , Herpesviridae Infections/diagnosis , Ruminants/virology , Enzyme-Linked Immunosorbent Assay/methods , Cross-Sectional Studies , Varicellovirus/isolation & purification , Herpesviridae Infections/immunology
12.
Mem. Inst. Oswaldo Cruz ; 115: e200287, 2020. tab, graf
Article in English | LILACS | ID: biblio-1154869

ABSTRACT

BACKGROUND The heat-labile nature of Dengue virus (DENV) in serum samples must be considered when applying routine diagnostic tests to avoid issues that could impact the accuracy of test results with direct implications for case management and disease reporting. OBJECTIVES To check if pre-analytical variables, such as storage time and temperature, have an impact on the accuracy of the main routine diagnostic tests for dengue. METHODS Virus isolation, reverse transcription real-time polymerase chain reaction (RT-PCR) and NS1 enzyme-linked immunosorbent assay (ELISA) were evaluated using 84 samples submitted to different pre-analytical conditions. FINDINGS Sensitivity and negative predictive value were directly affected by sample storage conditions. RT-PCR and virus isolation showed greater dependence on well-conserved samples for an accurate diagnosis. Interestingly, even storage at -30ºC for a relatively short time (15 days) was not adequate for accurate results using virus isolation and RT-PCR tests. On the other hand, NS1 ELISA showed no significant reduction in positivity for aliquots tested under the same conditions as in the previous tests. MAIN CONCLUSIONS Our results support the stability of the NS1 marker in ELISA diagnosis and indicate that the accuracy of routine tests such as virus isolation and RT-PCR is significantly affected by inadequate transport and storage conditions of serum samples.


Subject(s)
Humans , Immunologic Tests/methods , Enzyme-Linked Immunosorbent Assay/methods , Viral Nonstructural Proteins/immunology , Reverse Transcriptase Polymerase Chain Reaction/methods , Dengue/diagnosis , Dengue Virus/isolation & purification , Antigens, Viral/blood , Predictive Value of Tests , Sensitivity and Specificity , Viral Nonstructural Proteins/genetics , Dengue/blood , Dengue/virology , Dengue Virus/genetics , Dengue Virus/immunology , Antibodies, Viral/blood , Antigens, Viral/immunology
13.
Einstein (Säo Paulo) ; 18: eAO5132, 2020. tab, graf
Article in English | LILACS | ID: biblio-1056070

ABSTRACT

ABSTRACT Objective To evaluate the performance of enzyme-linked immunosorbent assay and indirect immunofluorescence methods for the detection of antineutrophil cytoplasmic antibodies in a routine clinical laboratory setting. Methods A total of 227 samples were tested by indirect immunofluorescence and enzyme-linked immunosorbent assay with antigen specificity for antiproteinase 3 and antimyeloperoxidase. The proportions of positive samples were compared by McNemar hypotheses and agreement was described by Cohen's Kappa coefficient. Results The agreement of the tests was 96.5%, and the Kappa coefficient obtained was 0.70 (95%CI: 0.50-0.90; p<0.001). Considering indirect immunofluorescence as the gold standard, the sensitivity of the enzyme-linked immunosorbent assay was 0.62 and the specificity was 0.99, with diagnostic accuracy in 96% of cases. Some samples were negative in enzyme-linked immunosorbent assay and positive in indirect immunofluorescence. This situation occurred in all immunofluorescence patterns, but particularly in atypical patterns. Two samples with antiproteinase 3 positivity were considered negative in indirect immunofluorescence. Conclusion The enzyme-linked immunosorbent assay had high specificity but lower sensitivity. The performance of indirect immunofluorescence increases diagnostic sensitivity, while the search for antiproteinase 3 by enzyme-linked immunosorbent assay may also add diagnostic power.


RESUMO Objetivo Avaliar o desempenho das metodologias de ensaio imunoenzimático e imunofluorescência indireta para a detecção de anticorpos anticitoplasma de neutrófilos em um contexto de laboratório clínico de rotina. Métodos Foram testadas 227 amostras pelas metodologias de imunofluorescência indireta e ensaio imunoenzimático com especificidades para anticorpos antiproteinase-3 e antimieloperoxidase. As proporções de amostras positivas foram comparadas por hipóteses de McNemar, e a concordância foi descrita pelo coeficiente Kappa de Cohen. Resultados A concordância dos testes foi 96,5%, e o coeficiente Kappa obtido foi 0,70 (IC95%: 0,50-0,90; p<0,001). Utilizando a imunofluorescência indireta como padrão-ouro, a sensibilidade do ensaio imunoenzimático foi de 0,62 e a especificidade, 0,99, com acurácia diagnóstica em 96% dos casos. Algumas amostras apresentaram resultados negativos por ensaio imunoenzimático e positivos por imunofluorescência. Isso ocorreu em amostras com vários padrões de fluorescência, mas particularmente nos casos com padrões atípicos. Duas amostras com positividade antiproteinase 3 foram consideradas negativas por imunofluorescência. Conclusão Os métodos de ensaio imunoenzimático tiveram alta especificidade, mas sensibilidade inferior. A realização da imunofluorescência indireta aumenta a sensibilidade diagnóstica, ao mesmo tempo que a pesquisa de antiproteinase 3 por ensaio imunoenzimático também pode agregar poder diagnóstico.


Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Antibodies, Antineutrophil Cytoplasmic/blood , Reference Standards , Reference Values , Autoimmune Diseases/diagnosis , Autoimmune Diseases/immunology , Autoimmune Diseases/blood , Predictive Value of Tests , Reproducibility of Results
14.
Einstein (Säo Paulo) ; 18: eAO5078, 2020. tab
Article in English | LILACS | ID: biblio-1056051

ABSTRACT

ABSTRACT Objective: To evaluate the performance of indirect immunofluorescence for serological diagnosis of dengue virus in a population with high prevalence of arboviruses. Methods: Two-hundred serum samples from patients with clinical suspicion of dengue fever were tested by immunoenzymatic and indirect immunofluorescence assay BIOCHIP® mosaic. Specificity, sensitivity and Kappa coefficient were calculated. Discordant samples were tested by polymerase chain reaction for confirmation. Results: Of the 200 samples, 20% were positive and 80% negative for anti-dengue virus IgM antibodies in the immunoenzymatic test. Of the 40 positives, 25% were negative in indirect immunofluorescence. Of these ten discordant results, only 20% were also negative in the polymerase chain reaction (PCR). Of the 160 negatives in the immunoenzymatic test, 5% were positive in indirect immunofluorescence. Of these nine discordant results, 33% were positive in the PCR. The Kappa coefficient was 0.7 (0.572-0.829). Sensitivity and specificity of indirect immunofluorescence were respectively 75% and 94%. For anti-dengue virus IgG antibodies, of the 200 samples, 15.5% were positive and 84.5% were negative in the immunoenzymatic test. Of the 31 positives, 12.9% were negative in indirect immunofluorescence. Of these four discordant results, 25% were negative in the PCR. Of the 169 negatives, 8% were positive in indirect immunofluorescence. Of these 14 discordant results, 64% were also positive in the PCR. The Kappa coefficient was 0.695 (0.563-0.83). Sensitivity and specificity of indirect immunofluorescence were 87.1% and 91.7%, respectively. Conclusion: For diagnosis of acute infection, the immunoenzymatic test is enough, and the use of additional methods is not warranted. Replacing the immunoenzymatic test by indirect immunofluorescence would compromise the sensitivity for IgM. However, indirect immunofluorescence can distinguish three arboviruses simultaneously, an advantage during concomitant epidemics.


RESUMO Objetivo: Avaliar o desempenho da imunofluorescência indireta no diagnóstico sorológico de dengue em uma população com alta prevalência de arboviroses. Métodos: Duzentas amostras de soro de pacientes com suspeita clínica de dengue foram testadas por ensaio imunoenzimático e imunofluorescência indireta mosaico BIOCHIP®. Foram calculados especificidade, sensibilidade e coeficiente Kappa. Nas amostras discordantes, realizou-se reação em cadeia da polimerase como método confirmatório. Resultados: Das 200 amostras, 20% foram positivas e 80% negativas para IgM antivírus da dengue no ensaio imunoenzimático. Das 40 positivas, 25% foram negativas na imunofluorescência indireta. Destas dez negativas, apenas 20% eram também negativas na reação em cadeia da polimerase. Das 160 negativas no ensaio imunoenzimático, 5% foram positivas na imunofluorescência indireta. Por fim, dentre as nove discordantes, 33% tiveram vírus da dengue detectado na reação em cadeia da polimerase. O coeficiente Kappa foi 0,70 (0,57-0,82). Sensibilidade e especificidade por imunofluorescência indireta foram, respectivamente, 75% e 94%. Para IgG antivírus da dengue, de 200 amostras, 15,5% foram positivas e 84,5% negativas no ensaio imunoenzimático. Das 31 positivas, 12,9% foram negativas na imunofluorescência indireta. Destas quatro discordantes, 25% apresentaram vírus da dengue não detectado na reação em cadeia da polimerase. Das 169 negativas, 8% foram positivas na imunofluorescência indireta. Destas, 64% foram positivas também na reação em cadeia da polimerase. O coeficiente Kappa foi 0,695 (0,56-0,83). Sensibilidade e a especificidade por imunofluorescência indireta foram, respectivamente, 87,1% e 91,7%. Conclusão: Ensaio imunoenzimático seria suficiente para diagnóstico sorológico de infecção aguda, não justificando a incorporação da imunofluorescência indireta. Substituir ensaio imunoenzimático pela imunofluorescência indireta poderia comprometer a sensibilidade para IgM. Contudo, a imunofluorescência indireta auxilia diferenciar três arboviroses simultaneamente, sendo vantajoso em epidemias concomitantes.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Dengue/diagnosis , Arboviruses/isolation & purification , Reference Standards , Brazil , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Enzyme-Linked Immunosorbent Assay/standards , Serologic Tests/methods , Serologic Tests/standards , Polymerase Chain Reaction , Sensitivity and Specificity , Fluorescent Antibody Technique, Indirect/standards , Dengue/immunology , Dengue Virus/isolation & purification , Antibodies, Viral/immunology
15.
Einstein (Säo Paulo) ; 18: eRW4890, 2020. tab, graf
Article in English | LILACS | ID: biblio-1056050

ABSTRACT

ABSTRACT Objective To demonstrate the impact of pneumococcal conjugate vaccine in Streptococcus pneumoniae carriage status in children younger than 5 years in Latin America and the Caribbean. Methods A systematic literature review was carried out on the direct and indirect effects of pneumococcal vaccine in the carriage status, after implementation in childhood immunization programs. Studies carried out in children younger than 5 years were selected from the PubMed® and Virtual Health Library databases, and data collected after implementation of pneumococcal vaccine in Latin America and the Caribbean, between 2008 and 2018. Results From 1,396 articles identified, 738 were selected based on titles and abstracts. After duplicate removal, 31 studies were eligible for full-text reading, resulting in 6 publications for analysis. All selected publications were observational studies and indicated a decrease in the carriage and vaccine types, and an increase in the circulation of non-vaccine serotypes, such as 6A, 19A, 35B, 21 and 38. We did not identify changes in the antimicrobial resistance after vaccine implementation. Conclusion A decrease in the carriage status of vaccine types and non-vaccine types was detected. The continuous monitoring of pneumococcal vaccine effect is fundamental to demonstrate the impact of the carriage status and, consequently, of invasive pneumococcal disease, allowing better targeting approaches in countries that included pneumococcal vaccine in their immunization programs. Our study protocol was registered in PROSPERO (www.crd.york.ac.uk/prospero) under number CRD42018096719.


RESUMO Objetivo Demonstrar o impacto das vacinas pneumocócicas conjugadas no estado de portador de Streptococcus pneumoniae em crianças menores de 5 anos na América Latina e no Caribe. Métodos Foi realizada revisão sistemática da literatura sobre os efeitos diretos e indiretos da vacina pneumocócica no estado de portador em crianças menores de 5 anos, após a implantação da vacina nos calendários de imunização infantil. A partir de dados da PubMed®e da Biblioteca Virtual da Saúde, foram selecionados estudos de portador em crianças menores de 5 anos, com dados coletados após implementação da vacina de 2008 a 2018, na América Latina e no Caribe. Resultados Dos 1.396 artigos identificados, 738 foram selecionados mediante leitura de títulos e resumos. Após a extração dos duplicados, 31 foram elegíveis para leitura do texto completo, restando 6 artigos para análise. Todos os estudos selecionados eram observacionais e indicavam diminuição do portador e tipos vacinais, e aumento da circulação de sorotipos não vacinais, como 6A, 19A, 35B, 21 e 38. Não foi observada alteração na resistência antimicrobiana após a introdução da vacina. Conclusão Detectou-se redução no estado de portador, dos tipos vacinais e não vacinais. O monitoramento contínuo do efeito das vacinas pneumocócicas é fundamental, para demonstrar o impacto do estado de portador e, consequentemente, da doença pneumocócica invasiva, permitindo o melhor direcionamento nas ações em saúde para os países que incluíram a vacina no calendário de imunização. Nosso protocolo de estudo foi registrado no PROSPERO (www.crd.york.ac.uk/prospero) sob o número CRD42018096719.


Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Dengue/diagnosis , Arboviruses/isolation & purification , Reference Standards , Brazil , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Enzyme-Linked Immunosorbent Assay/standards , Serologic Tests/methods , Serologic Tests/standards , Polymerase Chain Reaction , Sensitivity and Specificity , Fluorescent Antibody Technique, Indirect/standards , Dengue/immunology , Dengue Virus/isolation & purification , Antibodies, Viral/immunology
16.
Rev. chil. infectol ; 36(5): 650-655, oct. 2019. tab
Article in Spanish | LILACS | ID: biblio-1058091

ABSTRACT

Resumen La ehrlichiosis es una enfermedad transmitida por la picadura de garrapatas que afecta a perros y humanos, causada por las especies Ehrlichia canis y E. chaffeensis, respectivamente. Estas bacterias son gramnegativas, intracelulares obligadas, de aspecto cocoide a pleomorfo, que infectan los monocitos y desencadenan síntomas como fiebre elevada, anorexia, trombocitopenia, hemorragias, anemia y problemas graves como esplenomegalia, hepatomegalia y meningitis. Para diagnosticar esta enfermedad existen diversos métodos, entre los que se encuentran los hematológicos que evalúan la morfología de los monocitos en búsqueda de mórulas y la serología, que incluye la búsqueda de anticuerpos anti-Ehrlichia, pero que se encuentra limitado debido a la reactividad cruzada que presenta. Por otra parte, el cultivo de especies de Ehrlichia ha resultado ser un método efectivo para la obtención de antígenos y así desarrollar ensayos por inmunofluorescencia indirecta (IFI). El método por reacción de polimerasa en cadena ofrece un diagnóstico definitivo por tener una mayor sensibilidad y especificidad que los otros métodos, al haberse desarrollado cebadores género-específicos, así como especie-específicos. En esta revisión, se discutirán los diversos métodos aplicados al diagnóstico de esta enfermedad, así como las ventajas y desventajas que estos presentan.


Ehrlichiosis is a disease transmitted by tick's bite that affect dogs and humans caused by the species Ehrlichia canis and E. chaffeensis, respectively. These bacteria are obligated intracellular gram negatives, with a cocoid to pleomorph aspect and can infect monocytes and trigger symptoms such as high fever, anorexia, thrombocytopenia, hemorrhages, anemia, and some serious problems such as splenomegaly, hepatomegaly and meningitis. There are several diagnostic tests for ehrlichiosis such as the hematological ones that evaluate the morphology of the monocytes in search of morulae; serological tests that includes the search of anti-Ehrlichia antibodies, although they might be limited due to cross reaction with other species. In other hand, the culture of Ehrlichia species is an effective method to obtain antigens and even develop indirect immunofluorescence assays (IFA). The polymerase chain reaction offers a definitive diagnosis associated to the use of genus-specific and species-specific primers, as well as its increased sensibility and specificity, compared to the others methods. Thus, in this review, we will discuss various methods applied to the diagnosis of this disease, as well as the advantages and disadvantages that these present.


Subject(s)
Humans , Animals , Ehrlichiosis/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Serologic Tests/methods , Polymerase Chain Reaction/methods , Ehrlichia chaffeensis/isolation & purification , Fluorescent Antibody Technique, Indirect/methods , Ehrlichia canis/isolation & purification , Dogs
17.
Acta bioquím. clín. latinoam ; 53(3): 353-360, set. 2019. graf, tab
Article in Spanish | LILACS | ID: biblio-1038106

ABSTRACT

La neurocisticercosis (NCC) es la localización en el sistema nervioso central (SNC) humano de la parasitosis provocada por el estadio larvario de la Taenia solium, el cisticerco, que prevalece en áreas urbanas y rurales y constituye un problema de salud pública. El diagnóstico puede efectuarse por exploración imagenológica del SNC con resonancia magnética o tomografía axial computarizada, no siempre disponible, y por pruebas de inmunoensayo (EIA) en sangre, que aportan al diagnóstico rapidez, bajo costo y transferibilidad. Para evaluar su capacidad diagnóstica y validar la precisión de la técnica de ELISA (ensayo inmunoabsorbente ligado a enzimas), en la detección de anticuerpos anti-cisticercos en sueros humanos, se diseñó una seroteca en forma aleatoria y en doble ciego, y se realizó el ELISA con las muestras, utilizando placas sensibilizadas con antígenos obtenidos del fluido vesicular de cisticercos de T. solium. Para la validación se realizaron 20 ensayos empleando controles positivos y negativos, por cuadruplicado en diferentes días, y realizados por más de un operador; el punto de corte para este método fue una densidad óptica de 0,325. La precisión intralaboratorio para el control débil (media=0,532±0,09) fue de %CV=17,51±0,09, y un valor de repetibilidad de %CV=7,04±0,04, cifras que se encuentran dentro de los límites esperados para el método. Con estos resultados se puede concluir que la precisión del ELISA para el serodiagnóstico de NCC se encuentra validada. El ensayo validado proporcionó resultados coherentes y repetidos que permitieron discriminar entre dos resultados dicotómicos y establecer con exactitud la condición de una posible infección, con un nivel de certidumbre estadística predeterminado.


Neurocysticercosis (NCC) is the location in the human central nervous system (CNS) of the parasitosis caused by the larval stage of Taenia solium, the cysticercus which prevails in urban and rural areas, constituting a public health problem. Diagnosis can be made by CNS imaging with magnetic resonance or computerized axial tomography, not always available, and by blood immunoassay (EIA) tests, which provide rapidity, low cost and transferability. In order to evaluate its diagnostic capacity and validate the ELISA (Enzyme- Linked ImmunoSorbent Assay) technique in the detection of anti-cysticercus antibodies in human sera, a collection of sera was designed in a randomized and double-blind manner, and the ELISA was performed with the samples, using plates sensitized with antigens obtained from the vesicular fluid of T. solium cysticerci. Twenty trials were conducted, using positive and negative controls, in quadruplicate, on different days, and performed by more than one operator; the cutoff for this method was an optical density of 0.325. The intralaboratory precision for the weak control (mean=0.532±0.09) was %CV=17.51±0.09, and a repeatability value of %CV=7.04±0.04, figures that are within the expected limits for the method, It can be concludedthat the accuracy of the ELISA for serodiagnosis of NCC is validated. The validated test provided consistent and repeated results, which made it possible to discriminate between two dichotomous outcomes, and to establish with accuracy the condition of a possible infection, with a predetermined level of statistical certainty.


A neurocisticercose (NCC) é o local no sistema nervoso central (SNC) humano de parasitose causada pelo estágio larval da Taenia solium, o cisticerco, prevalecente em áreas urbanas e rurais, constituindo um problema de saúde pública. O diagnóstico pode ser feito por varredura imagenológica do SNC com ressonância magnética ou tomografia axial computadorizada, nem sempre disponível, e por testes de imunoensaio (EIA) em sangue, que fornecem ao diagnóstico rapidez, baixo custo e portabilidade. Para avaliar a sua capacidade de diagnóstico e validar a precisão da técnica de ELISA (ensaio imunoabsorvente ligado a enzimas), na detecção de anticorpos anti-cisticercos em soros humanos, um serrarium foi projetado em forma aleatória e em duplo cego, e foi realizado com as amostras o ELISA, utilizando placas sensibilizadas com antígenos derivados do fluido vesicular de cisticercos de T. solium. 20 testes para validação foram realizados, utilizando controles positivos e negativos, em quadruplicado, em dias diferentes, e realizados por mais de um operador; o ponto de corte para este método era uma densidade óptica de 0,325. A precisão intralaboratorial para o controle fraco (média=0,532±0,09) foi de CV%=17,51±0,09, e um valor de repetibilidade de CV%=7,04±0,04, valores que estão dentro dos limites esperados para o método, podendo concluir com esses resultados que a precisão do ELISA para diagnóstico sorológico de NCC é validado. O ensaio validado forneceu resultados consistentes e repetidos, o que permitiu discriminar entre dois resultados dicotômicos e identificar com exatidão a condição de possível infecção com um nível de certeza pré-determinado estatisticamente.


Subject(s)
Humans , Cysticercosis/diagnosis , Neurocysticercosis/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Taenia solium , Antibodies/blood
18.
Rev. cuba. med. trop ; 71(2): e382, mayo.-ago. 2019. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1093566

ABSTRACT

El diagnóstico de fasciolosis humana, enfermedad zoonótica causada por el parásito Fasciola hepatica reúne los resultados de las técnicas: concentración por sedimentación (copa-cónica), FasciDIG en heces y FasciDIG en suero, además de los criterios clínico-epidemiológicos. FasciDIG constituye un ensayo inmunoenzimático que detecta antígenos de excreción-secreción de F. hepatica a partir de muestra de suero y heces. Permite diagnosticar la infección en cada una de las formas clínicas de la enfermedad y presenta una sensibilidad diagnóstica superior a las técnicas convencionales que detectan huevos del parásito (copa-cónica), por lo que se consideró oportuno abordar algunos conceptos relacionados con esta técnica inmunodiagnóstica y analizar su aplicabilidad para el diagnóstico oportuno y eficaz de esta parasitosis(AU)


Diagnosis of human fasciolosis, a zoonotic disease caused by the parasite Fasciola hepatica, combines the results of the following techniques: conical cup, feces FasciDIG and serum FasciDIG, as well as clinical-epidemiological criteria. FasciDIG is an enzyme immunoassay that detects F. hepatica excretion / secretion antigens in serum and feces samples. It makes it possible to diagnose infection at each of the clinical stages of the disease with a higher diagnostic sensitivity than conical cup. Therefore, it was considered appropriate to address a number of concepts regarding this immunodiagnostic technique and analyze its applicability in the timely and effective diagnosis of this helminth infection(AU)


Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/methods , Immunoenzyme Techniques , Fasciola hepatica/immunology , Antibodies, Monoclonal/therapeutic use , Communication
19.
Braz. j. biol ; 79(2): 169-173, Apr.-June 2019. tab, graf
Article in English | LILACS | ID: biblio-989440

ABSTRACT

Abstract Even today, an effective diagnostic test for aspergillosis in penguins is unknown, being the gold standard post-mortem examinations. The fungal antigen galactomannan (GM) has been used as a biomarker of disease in humans and is detected by the Platelia Aspergillus EIA (BioRad)®, a commercial kit based on the sandwich ELISA technique. It is standardized for use in neutropenic patients, however studies have demonstrated its usefulness also possible for birds. The aim of our study was to evaluate the effectiveness of Platelia Aspergillus EIA® test (BioRad-US) in the diagnosis of aspergillosis in Magellanic penguins, determining sensitivity, specificity, and positive and negative predictive values for different cut-off points. Were included in the study, blood serum samples (n = 29) Magellanic penguins in captivity that died by aspergillosis. Detection of GM was performed following manufacturer's instructions and the GM index was obtained by dividing the average value of OD of the duplicate of the clinical sample by duplicate OD of the average value of the cut-off sample provided by the kit. Through information database results were obtained for the presence of anti-Aspergillus fumigatus antibodies detected by agar gel immunodiffusion (AGID) for all serum samples. Results were analyzed using chi-square test and Kruskal-Wallis from SPSS 20.0, IBM®. ROC curve was obtained and from this, rates of sensitivity, specificity, positive and negative predictive values were also calculated based on four different cutoff points (0.5, 1.0, 1.5 and 2.0). The serum GM index did not differ between animals of the case and control group (pkw =0.097). In determining the ROC curve for serum GM detection the value of area under the curve was 0.635. From the values ​​determined by the coordinate of the curve, four different cut points (0.5, 1.0, 1.5 and 2.0) were analyzed, resulting in sensitivity rates ranging from 86.2 to 34.5% % and specificity between 87% and 26.1%. By comparing the serum GM index in group case as the presence or absence of antibodies detected by AGID was found p=0.503. The detection of GM the Platelia Aspergillus EIA® test seems is not be useful for the diagnosis of aspergillosis in naturally infected penguins.


Resumo Ainda hoje, um teste diagnóstico eficaz para aspergilose em pinguins não é conhecido, sendo o padrão-ouro os exames post-mortem. O antígeno fúngico galactomanana (GM) tem sido utilizado como biomarcador da doença em humanos, sendo detectado pelo Platelia Aspergillus EIA (BioRad)®, um kit comercial que se baseia na técnica ELISA sanduíche. É padronizado para utilização em pacientes neutropênicos, no entanto estudos tem demonstrado sua possível utilidade também para aves.O objetivo de nosso estudo foi avaliar a eficácia do teste Platelia Aspergillus EIA® (BioRad-US) no diagnóstico da aspergilose em pinguins-de-Magalhães, determinando sensibilidade, especificidade e valores preditivos positivos e negativos em diferentes pontos de corte. Foram incluídas no estudo, amostras de soro sanguíneo (n=29) de pinguins-de-Magalhães em cativeiro que vieram a óbito por aspergilose. A detecção de GM foi realizada seguindo instruções do fabricante e o índice de GM foi obtido dividindo o valor da média da DO da duplicata da amostra clínica pelo valor da média da DO da duplicata da amostra de cut-off fornecida pelo kit. Através de informações em banco de dados foram obtidos resultados sobre a presença de anticorpos anti-Aspergillus fumigatus, detectada por Imunodifusão em gel de ágar (IDGA) em todas as amostras séricas. Os resultados foram analisados utilizando-se teste de qui-quadrado e Kruskal-Wallis a partir do programa estatístico SPSS 20.0, IBM®. Curva ROC foi obtida e a partir desta, taxas de sensibilidade, especificidade, valores preditivo positivo e negativo foram igualmente calculados considerando quatro diferentes pontos de corte (0.5, 1.0, 1.5 e 2.0). O índice de GM sérica não diferiu entre os animais do grupo caso e controle (pKW = 0.097). Na determinação da curva ROC para detecção de GM sérica o valor da área sobre a curva foi de 0.635. A partir dos valores determinados pelas coordenadas da curva, quatro diferentes pontos de corte (0.5, 1.0, 1.5 e 2.0) foram analisados, resultando em taxas de sensibilidade variando de 86.2% a 34.5%, e de especificidade entre 87% e 26.1%. Ao comparar o índice de GM sérica nos animais do grupo caso quanto a presença ou não de anticorpos detectados pela IDGA foi encontrado p=0.503. A detecção de GM pelo teste Platelia Aspergillus EIA® não parece ser útil para o diagnóstico da aspergilose em pinguins naturalmente infectados.


Subject(s)
Animals , Aspergillosis/diagnosis , Aspergillosis/veterinary , Aspergillus/isolation & purification , Enzyme-Linked Immunosorbent Assay/methods , Spheniscidae/microbiology , Biomarkers/analysis , Mannans/analysis
20.
Rev. cuba. med. trop ; 71(1): e325, ene.-abr. 2019. tab
Article in Spanish | LILACS, CUMED | ID: biblio-1093546

ABSTRACT

Introducción: En el diagnóstico microbiológico de la brucelosis, los métodos serológicos son los más utilizados. Brucellacapt® ofrece la ventaja de detectar en cualquier momento de la enfermedad anticuerpos aglutinantes y no aglutinantes contra Brucellaspp. Objetivos: Evaluar y aplicar el sistema serológico comercial Brucellacapt® para la detección de anticuerpos contra Brucella spp. Métodos: Se realizó una investigación en servicios y sistemas de tipo observacional con un estudio de caso control anidado, en el periodo de enero de 2015 a junio de 2016, en el Laboratorio Nacional de Referencia de Espiroquetas y Brucelas. Se evaluaron 50 sueros de casos y 100 de controles por Brucellacapt®. Se aplicó Brucellacapt® en 695 sueros de casos con sospecha clínica o epidemiológica de la enfermedad, los cuales fueron confirmados por ELISA. Resultados: Brucellacapt® mostró 100 por ciento de sensibilidad, 83 por ciento de especificidad, 54,6 por ciento de reactividad y 16,4 por ciento de positividad en las muestras estudiadas. Se confirmó por ELISA la presencia de anticuerpos IgM (21, 2 por ciento), IgG (6,1 por ciento) e IgM + IgG (7,6 por ciento). Doscientas cuarenta y seis muestras y otras siete fueron reactivas y positivas respectivamente, solo por Brucellacapt®. Conclusiones: Brucellacapt® contribuyó a la detección de anticuerpos en los sueros de pacientes sospechosos de la enfermedad con valores aceptables de sensibilidad y especificidad diagnóstica. Este resultado sugiere su implementación en la red nacional de laboratorios cubanos para fortalecer el diagnóstico y la vigilancia de la brucelosis humana en Cuba(AU)


Introduction: Serological methods are the most commonly used for the microbiological diagnosis of brucellosis. Brucellacapt® has the advantage of detecting agglutinating and non-agglutinating antibodies against Brucella spp. at any point in the evolution of the disease. Objectives: Evaluate and apply the commercially available serological system Brucellacapt® for detection of antibodies against Brucella spp. Methods: A nested case-control observational study was conducted of services and systems from January 2015 to June 2016 at the Spirochaete and Brucella National Reference Laboratory. Evaluation was performed of 50 serum samples from cases and 100 from controls using Brucellacapt®. The system was also used in 695 serum samples from clinically or epidemiologically suspected cases, which were confirmed by ELISA. Results: Brucellacapt® showed 100 percent sensitivity, 83 percent specificity, 54.6 percent reactivity and 16.4 percent positivity in the samples studied. Presence of the following antibodies was confirmed by ELISA: IgM (21.2 percent), IgG (6.1 percent) and IgM + IgG (7.6 percent). Two hundred forty-six samples and another seven were reactive and positive, respectively, only by Brucellacapt®. Conclusions: Brucellacapt® contributed to antibody detection in serum samples from suspected cases, with acceptable diagnostic sensitivity and specificity values. This result suggests its implementation in the Cuban national network of laboratories to strengthen the diagnosis and surveillance of human brucellosis in Cuba(AU)


Subject(s)
Humans , Brucellosis/diagnosis , Serologic Tests/methods , Enzyme-Linked Immunosorbent Assay/methods , Cuba
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