Estudo de homogeneidade dos soros utilizados em controle de qualidade interno de testes imunodiagnósticos de HIV/Aids / AidsHomogeneity study of the internal quality control sera for immunodiagnosis of HIV/AIDS

Introduction: The present study reports the data from the first homogeneity assessment of samples composing the serum panels produced at the Immunology Center of Instituto Adolfo Lutz, São Paulo. These samples have been distributed to the public laboratories and those partaking in the Brazilian Unified Health System, and to the participants in the Internal Quality Control Program for human immunodeficiency virus (HIV) antibody (Ab) testing. Objective: To assess the homogeneity of serum samples in panels from different lots for HIV/acquired immunodeficiency syndrome (AIDS) immunodiagnosis by using the statistical method to ensure quality of the reference material. Method: Sera homogeneity was evaluated by means of enzyme-linked immunoassay/enzyme immunoassay (ELISA/EIA) for detection of HIV Ab, and the one-way analysis of variance was employed for analyzing the data. No statistically significant differences were found among the several serum vials. Conclusion: The sera dispensed in the vials were homogeneous in the respective lots...

Introdução: No presente estudo estão descritos os resultados das primeiras análises feitas sobre a avaliação da homogeneidade das amostras componentes de painéis de soros produzidos no Centro de Imunologia do Instituto Adolfo Lutz e distribuídos aos laboratórios públicos e conveniados ao Sistema Único de Saúde e participantes do Programa de Controle de Qualidade Interno para imunodiagnóstico de vírus da imunodeficiência humana/síndrome da imunodeficiência adquirida (HIV/AIDS). Objetivo: Avaliar a homogeneidade das amostras de soro componentes de painéis de diferentes lotes para imunodiagnóstico de HIV/Aids por meio de método estatístico para garantir a qualidade do material de referência. Material e método: A homogeneidade das amostras de soro foi avaliada por meio de enzyme-linked immunoassay/enzyme immunoassay (ELISA/EIA) para detecção de anticorpos anti-HIV, e os resultados foram submetidos à análise de variância fator único. Não foram encontradas diferenças significativas entre os resultados obtidos para os diversos frascos de soro. Conclusão: As amostras distribuídas nos frascos foram homogêneas entre si nos respectivos lotes...

Padronização e uso de um método imunoenzimático que utiliza células infectadas como antígeno no diagnóstico rotineiro do dengue / Standardization and use of an immunoenzymatic method using infected cells as antigens in routine diagnosing of dengue

INTRODUÇÃO: Este trabalho mostra a padronização e o uso do método imunoenzimático utilizando células infectadas como antígeno (EIA-ICC) no diagnóstico sorológico rotineiro do dengue. MÉTODOS: Na otimização do teste, com a dose de 1.000 TCID50 de vírus do dengue tipo 3 (DENV-3), foram utilizadas 100.000 células C636 infectadas 1000 TCID50 (DENV-3). RESULTADOS: Os resultados obtidos com EIA-ICC foram comparados com o kit comercial de dengue HUMAN. Os resultados foram altamente coincidentes; o EIA-ICC mostrou-se moderadamente sensível e com alta especificidade. O teste foi usado no diagnóstico sorológico de 1.797 amostras sorológicas de casos suspeitos de dengue durante a epidemia de Ribeirão Preto, em 2006. Na avaliação sorológica, 228 amostras foram positivas para IgM contra DENV-3, e 235 amostras foram positivas para IgG contra DEV-3, e em 35 amostras detectou-se positividade para IgM e IgG. CONCLUSÕES: O EIA-ICC mostrou-se confiável e simples sendo adequado ao diagnóstico sorológico do dengue.

INTRODUCTION: This paper show the standardization and use of the immunoenzymatic method using infected cells as antigens (EIA-ICC) for routine serological diagnosing of dengue. METHODS: In optimizing the test, a dose of 1,000 TCID50 of dengue type 3 virus (DENV-3) was used, and 100,000 C636 cells infected with 1,000 TCID50 (DENV-3) were used. RESULTS: The results obtained with EIA-ICC were compared with the HUMAN commercial dengue kit. The results were highly concordant. The EIA-ICC showed moderate sensitivity and high specificity. The test was used for serologically diagnosing 1,797 blood samples from suspected dengue cases during the 2006 epidemic in Ribeirao Preto. From the serological evaluation, 228 samples were positive for IgM against DENV-3; 235 samples were positive for IgG against DENV-3; and 35 samples were positive for both IgG and IgM. CONCLUSIONS: EIA-ICC was shown to be reliable and simple, and suitable for serologically diagnosing dengue.

Evaluación de neoantígenos en concentrados de factor VIII analizados por enzimoinmunoensayo / Neoantigens evaluation on F VIII concentrates analyzed by enzymeimmunoassay (EIA)

El propósito de este estudio fue evaluar la inmunogenicidad de concentrados de factor VIII producidos en UNC-Hemoderivados antes y después del tratamiento térmico empleando un enzimoinmunoensayo (EIE) desarrollado en nuestro laboratorio. Materiales y método: Para ese propósito se obtuvieron anticuerpos contra factor VIII calentado y no-calentado por inmunización de conejos y la inmunoglobulina G específica fue aislada por afinidad a Proteína A-Sepharosa. El EIE fue realizado empleando como antígeno de captura el factor VIII con o sin tratamiento térmico (0.5 ug/pocillo), los sitios inespecíficos bloqueados con albúmina al 2 por ciento y el anticuerpo revelado con un anti-IgG de conejo conjugada a peroxidasa. La presencia de neoantígenos fue estudiada por incubar durante 2 hs a 37°C y luego a 4°C toda la noche, con cantidades crecientes de factor VIII antes y después del tratamiento térmico (0.03 a 600 ug de proteínas), con cantidades adecuadas de IgG anti-factor VIII calentado y no-calentado. Luego de centrifugar la muestra para la separación de los inmunocomplejos, se valoró la presencia de anticuerpos en el sobrenadante por EIE tanto para factor VIII calentado y no calentado. Resultados: Los resultados obtenidos permitieron observar que para ambos anticuerpos (calentado y no calentado) se neutralizaba la misma cantidad de factor VIII calentado y no calentado (0.30 ug) y además, se pudo comprobar que esta conducta se repetía cuando se empleaban en el EIE como antígeno de captura, factor VIII con y sin tratamiento térmico. Conclusiones: Los datos obtenidos de este estudio nos permiten concluir que el tratamiento térmico aplicado a los concentrados de factor VIII elaborados en la UNC-Hemoderivados no producen ninguna formación de neoantígenos. A juzgar por el sensible y específico EIE desarrollado en nuestro laboratorio.

Introduction: with the purpose of improving viral security, plasma-derived products are generally subjects of solvent/detergent and heating (100°C for 30 minutes) treatment which are introduced during the manufacturing process. The formation of neoantigens in factor VIII concentrates produced after the heat treatment could trigger an immune response against the modified protein and the native protein. Objetives: the purpose of this study was to evaluate the immunogenicity of factor VIII concentrates produced in UNC-Hemoderivados before and after heat treatment, using an EIA developed in our laboratory. Materials and methods: antibodies against factor VIII with and without heating treatment were obtained by rabbit immunization. The specific IgG was isolated by protein-A-Sepharose affinity chromatograpy. Two EIA plates were coated (0.5 ug/well) one with factor VIII heated (H) and the other one with factor VIII no-heat (no-H) and the antibodies detection were performed using rabbit anti-lgG peroxidase conjugated. The neoantigens were studied by incubation of increasing concentrations of factor VIII (0.03-600 ug of proteins) before and after heating treatment during 2 hours at 37 °C and overnight at 4 °C with adequate concentrations of anti-factor VIII IgG (with and without treatment). The immunocomplexes were removed by centrifugation and the free antibodies in the supernatant were measured by EIA in plates H and no-H. Results: the EIA showed a linear behavior between antibodies dilution ranged from 1/8000 to 1/512000. With these results we can conclude that the same concentration of factor VIII heated and unheated (0.30 ug) were neutralized with either antibodies (heated and unheated). These results were similar in both EIA plates coated with factor VIII H and no-H...

Evaluation of the concomitant use of two different EIA tests for HIV screening in blood banks

OBJECTIVE: In 1998, the Brazilian Ministry of Health made it mandatory for all blood banks in the country to screen donated blood for human immunodeficiency virus (HIV) concomitantly using two different enzyme immunoassay (EIA) tests. Concerned with the best use of available resources, our objective with this study was to evaluate the usefulness of conducting two EIA screening tests instead of just one. METHODS: We analyzed data from 1999 through 2001 obtained by testing 698 191 units of donated blood using two EIA HIV screening tests concomitantly at the Pro-Blood Foundation/Blood Center of Säo Paulo (Fundaçäo Pró-Sangue/Hemocentro de Säo Paulo), which is a major blood center in the city of Säo Paulo, Brazil. All samples reactive in at least one of the two EIA tests were submitted for confirmation by a Western blot (WB) test, and the persons who had donated those samples were also asked to return and provide a follow-up sample. RESULTS: Out of the 698 191 blood units that were donated, 2 718 of them (0.4 percent) had to be discarded because they were reactive to at least one of the EIA tests. There were two WB-positive donation samples that were reactive in only one HIV EIA screening test. On their follow-up samples, both donors tested WB-negative. These cases were considered false positive results at screening. Of the 2 718 donors who were asked to return and provide a follow-up sample, 1 576 of them (58 percent) did so. From these 1 576 persons, we found that there were two individuals who had been reactive to only one of the two EIA screening tests and who had also been negative on the WB at screening but who were fully seroconverted on the follow-up sample. We thus estimated that, in comparison to the use of a single EIA screening test, the use of two EIA screening tests would detect only one extra sample out of 410 700 units of blood. CONCLUSIONS: Our data do not support the use of two different, concomitant EIA screening tests for HIV. The great majority of HIV-positive donors have already seroconverted and will be detected using only a single EIA screening test. Only persons who are going through the process of seroconversion may be missed by using a single EIA test and detected using two EIAs for screening. To screen out these individuals and decrease the residual risk of HIV transmission from the blood donated in our center, the use of other techniques, such as nucleic acid testing (NAT) or a p24 antigen assay, would be more effective

Padronizaçäo de ensaio imunoenzimático para pesquisa de anticorpos das classes IgM e IgG anti-Toxoplasma gondii e comparaçäo com a técnica de imunoflorescência indireta / Standardization of enzyme-linked immunosorbent assay ELISA to detect anti-Toxoplasma gondii IgM and IgG antibodies, and comparison with the indirect immunofluorescence technique

A sorologia tem sido o método de escolha para o diagnóstico da toxoplasmose. Devido a isto, padronizamos um ensaio imunoenzimático (ELISA) e comparamos seus resultados com a técnica de imunofluorescência indireta (IFI). A técnica padronizada apresentou na pesquisa de IgG sensibilidade (S) de 96,7 por cento e especificidade (E) de 75 por cento, com valor de prediçäo de positividade (VPP) de 83,3 por cento e de negatividade (VPN) de 94,7 por cento, com uma concordância ajustada (K) de 73,5 por cento. A IFI apresentou S de 83,8 por cento, E de 79,1 por cento com VPP de 83,8 por cento e VPN de 79,1 por cento com K de 63 por cento. A concordância bruta entre os dois testes (ELISA/IFI) foi de 88,3 por cento para pesquisa de IgG e de 81,5 por cento para pesquisa de IgM, sendo o K de 70,8 por cento para IgG e de 1,3 por cento para IgM, sendo o índice de correlaçäo (r) de 0,556 para IgG e de -O,023 para IgM. Podemos concluir que a ELISA-IgG padronizada é indicada nos processos de triagem sorológica, sendo a ELISA-IgM desaconselhada uma vez que apresentou baixos índices de concordância ajustada com a técnica de referência, sugerindo pouca confiabilidade dos resultados

El diagnóstico serológico de la hidatidosis humana con ELISA y hemaglutinación indirecta / Serologic diagnosis of human hydatidosis

El diagnóstico serológico de la hidatidosis humana es fundamental ya que su detección temprana posibilita el éxito de la quimioterapia. El objetivo de este trabajo fue demostrar la validez del ELISA y la importancia de su asociación con la determinación del antígeno circulante. Se estudiaron 870 muestras por los métodos: HAI y ELISA para dosaje de anticuerpos (EAc) y antígeno circulante mediante un ELISA de captura (EAg). De los 870 sujetos estudiados 144 tenían hidatidosis. De los 144 sujetos con hidatidosis, veintiséis correspondían a sujetos operados en el período 1990-1993 observándose una buena correspondencia entre los resultados obtenidos por la HAI y el EAc. El resto (118) corresponden a sujetos con diagnóstico prequirúrgico por imágenes y sus resultados muestran que el EAc permitió detectar mayor número de portadores de quistes pulmonares (veintitrés) que la HAI (catorce), significando una mayor sensibilidad diagnóstica (Chi cuadrado: 9,8). La sensibilidad de estos métodos fue de 83 por ciento para la HAI y 91 por ciento para el EAc. Fueron detectados cuatro falsos negativos por EAc mediante el EAg lográndose as161 una sensibilidad del 95 por ciento al asociar ambos métodos. También mediante el EAg se logró detectar recidivas y no se observó influencia del tamaño de los quistes en la reactividad

Estandarización de una técnica de enzimoinmunoensayo para el diagnóstico de la hidatidosis humana / Standardization of enzimoimmunoassay for human hydatidosis

Una de las actividades que realizan los programas de control de hidatidosis causada por Echinococcus granulosus es la búsqueda de portadores asintomáticos de quistes hidatídicos en la población general, que habita en las zonas de riesgo. Se propone un método inmunoenzimático sensibilizando las placas con antígeno de líquido hidatídico total (EIE-ALHT), siguiendo la técnica descrita en el trabajo. El "valor de corte" del EIE-ALHT para posibles portadores de quistes hidatídicos fue una densidad óptica mayor que X + 4 DS, donde el número de desviaciones estándares fue denominado i (i = 4). Se comparó EIE-ALHT con HAI y DD5. La Sensibilidad fue 94 por ciento vs. 88 por ciento y 44 por ciento; la Especificidad, 100 por ciento vs. 95 por ciento y 100 por ciento; el Valor Predictivo de un Resultado Negativo, 99 por ciento vs. 98 por ciento y 31 por ciento; la Eficiencia 99 por ciento vs. 94 por ciento y 55 por ciento, respectivamente. No se obtuvieron resultados reactivos en pruebas cruzadas con cisticercosis, sífilis, tuberculosis, artritis, reumatoidea y lupus eritematoso. El método resultó de bajo costo, práctico y sencillo y adaptable para estudios de detección de la hidatidosis en población general

Further evaluation of alternative strategy for HIV testing in India.

A total 320 sera from groups at risk for HIV were evaluated by two (198 specimens) or three (122 specimens) screening tests for confirmatory anti-HIV testing in comparison to Western Blot as gold standard. Sera positive by both screening tests showed 100% correlation with Western Blot although with a false positivity rate of 3.2%. In specimens positive by 1st screening test but negative by the second, (considered negative for anti-HIV antibody as per WHO algorithm), 8.7% were found to be Western Blot positive showing the serious problem of false negativity of the proposed WHO algorithm. Employing the system of three screening test systems did not provide additional benefit for the specimens positive by initial two screening tests since all of them were positive by third test also. However, the study involving three screening tests substantiated the need for Western Blot in discordant specimens (i.e. positive by first test but negative by second), since in this group one out of 22 (4.6%) such specimens were Western Blot positive. Considering the serious consequences of both false positive and false negative results, it is felt that alternative strategy of confirmatory anti-HIV serology, although economical may not be suitable substitute for Western Blot in India at this juncture when the prevalence of HIV infection is relatively low.

Alanine aminotransferase activity in mammary tissue, muscle and liver of dam rat during lactation and weaning

Transamination reaction is the first step in the catabolism of most of the L-amino acids. Alanine is an important molecule in the inter-organ nitrogen transport, conveying them from muscle to the liver Amino groups from this amino acid are generally first transferred to alfa-ketoglutarate in the cytosol of liver cells to form glutamate and leaving behing the corresponding alfa-keto acid analog. Measurements of the alanine aminotransferase (EC2.6.1.2.) activity were compared in liver, mammary gland an skeletal muscle in virgin, lactating and weaning dam rats. In this study liver was the principal tissue involved in alanine transamination, while muscle showed a reduction in the enzyme activity during lactation. Results indicate an increase in alanine aminotransferase activity in the mammary gland during lactation and weaning when compared with virgin rats. This suggest that mammary gland during lactation is an importan extra-hepatic tissue involved in the metabolism of alanine and probably shunted into hte pathways for amino group metabolism in terms of nitrogen economy

Hartmannella vermiformis isolated from the cerebrospinal fluid of a Young male patient with meningoencephalitis and bronchopneumonia

Meningoencephalitis and bronchopneumonia were documented in a patient from Puebla, Mexico. The patient began with symptoms and signs of a common flu and 12 days after the onser of his disease he was admitted to the hospital presentin symptoms and signs of meningoencephalitis. The clinical course evolved into an endocraneal hypertension syndrome with bronchopneumonia, coma and death. Wide-spectrum antibiotics, immunosuppressive and anti-tuberculosis therapy were unsuccessfully administered. Important antecedents were degree I malnutrition and repeated contact with polluted water. Post-mortem autopzy was not performed. Gram-positive cocci were isolated from the spinal fluid 2 days after admission, and then active amebae were isolated from three different samples of the spinal fluid at days 16, 18 and 19 after admission. Such samples were concentrated and inoculated onto specific culture media. Identification of amebae was based on their morphology and biochemistry. All amebae were hartmannella veriformis. Amebae were apparently not the cause of the disease and might be considered as an opportunistic colonizer which may have caused the evolution of the disease to become worse

Retrospective review of dot enzyme immunoassay test for typhoid fever in an endemic area.

Typhoid fever remains a common problem in Malaysia, but for its diagnosis both blood culture and the Widal test have drawbacks. A dot enzyme immunoassay (EIA) has been developed which detects IgM and IgG antibodies to a specific 50 kDa outer membrane protein on Salmonella typhi. This study was performed among outpatients attending the university hospital in Kelantan, a state on the east coast of Peninsular Malaysia where typhoid is endemic. The dot EIA was done on 149 outpatients of all ages in whom typhoid was suspected. Of these, 60 were not analysable due to insufficient data. The other 89 were retrospectively classed as typhoid (total = 21), or not typhoid (total = 68). The criteria for diagnosis of typhoid was either, blood culture was positive, or with blood culture negative, temperature was at least 38 degrees C and Widal O and/or H titer greater than or equal to 1/160. We then compared the diagnosis with the EIA result. For the result where either IgM or IgG was positive, sensitivity was 90%, specificity 91% and negative predictive value 97%. For IgM positive, specificity was 100%. But the specificity of IgG positive alone was reduced by six false positives, which were probably due to persistence of IgG after acute infection. Other cases were found where IgG positive alone appeared in the first week of typhoid fever, probably due to rapid response in a second or subsequent infection. We also found that IgM-producing patients were significantly younger than those showing IgG alone positive.

Anti-dengue IgG detection by an indirect ELISA.

Protein-free culture media were originally developed for hybridomas to simplify downstream processing and purification. For the same reasons, we have used these protein-free media for passaging dengue 2 virus in C6/36 cells. This provided us with an infected supernatant (DenPF) which could then be used as coating antigens for an indirect enzyme-linked immunosorbent assay (ELISA) to determine dengue IgG levels. Using this preparation, the main immunogenic band as seen by immunoblot appeared to be viral envelope protein (E). Without the high concentrations of "competing" proteins from fetal calf serum (FCS), the Den2PF could be directly coated onto 96-well ELISA plates. The amount of viral proteins in Den2PF appeared to be sufficient so that there was no need for further purification steps, eg polyethylene glycol (PEG) precipitation, which made this preparation cost effective. It compared favorably with the dengue dot enzyme immunoassay (DEIA; sensitivity of 95.7% and specificity of 95.2%).

El tratamiento de las intoxicaciones agudas causadas por carbamazepina, digoxina y ácido acetilsalicílico, mediante la administración de dosis repetidas de carbón activado / Treatment of acute intoxication caused by carbamazepine, digoxin and acetylsalycilic acid with repeated dose of activated charcoal

Se informa de doce pacientes pediátricos intoxicados en forma aguda, cuatro con carbamazepina, cuatro con digoxina y cuatro más con ácido acetilsalicílico. El tratamiento, además de las medidas generales de sostén y sintomáticas, consistió en la administración de dosis múltiples de carbón activado (superficie de adsorción aproximado de 950 m2/g), y un catártico salino al inicio, a la mitad y al final del tratamiento, cuya duración total fue de 24 a 36 horas. El procedimiento se consideró eficaz, pues además de la mejoría clínica de los pacientes, concomitantemente redujo las cifras plasmáticas de los fármacos responsables. Las cifras promediadas inicales de carbamazepina fueron de 21.64 ug/ml y las finales de 0.9 ug/ml, con un descenso neto de 95.8 por ciento (p<0.05). La digoxina de 5.14 y 1.1 ng/ml, con descenso de 78.6 por ciento (p<0.05), y finalmente, el ácido acetilsalicílico, cifra de 418.5 y 57.5 ug/ml respectivamente, con descenso de 86.3 por ciento (p<0.05). Estos resultados sugieren el papel del carbón activado en la depuración sistemática de los fármacos estudiados

Rendimiento diagnostico de la inmunodeficiencia y el ensayo inmunoenzimatico en sueros de pacientes con leishmaniasis del norte y del nordeste de Brasil / Diagnostic performance índices for immunofluorescent tests and enzyme immunoassays of leishmaniasis sera from northern and northeastern Brazil

Se examino un total de 341 muestras de suero para detectar anticuerpos IgA, IgG e IgM anti-Leishmania mediante pruebas de inmunofluorescencia (IF) y ensayos inmunoenzimaticos (ELISA). En conjunto, 292 de los sueros pertenecian a pacientes con diagnosticos clinicos y parasitologicos de leishmaniasis cutanea (resultados positivos en la impronta de lesiones o en la prueba cutanea de Montenegro) y 49, a controles de la misma poblacion. Los índices de rendimiento diagnostico de los ELISA-IgG e IgM fueron de utilidad diagnostica y el valor predictivo positivo del ELISA-IgG fue de 94,6. . La especificidad de la prueba de IF-IgA fue notablemente alta (100. ), pero su sensibilidad fue muy baja

Estudio de cervicopatías en la II región usando la técnica de inmunoperoxidasa con complejo de avidina biotina / Study of cervical pathology in the II region using immunoperoxidase technic with avidin-biotin complex

En Chile se diagnostican alrededor de 1.500 cánceres invasores de cuello uterino cada año, la mayoría en etapas avanzadas, lo que determina una mortalidad cercana al 50 por ciento. Ultimamente se ha ido aportando evidencia del rol etiológico de los virus papiloma en el cáncer cérvico uterino, basada en la confirmación epidemiológica que este cáncer se comporta como una enfermedad de transmisión sexual altamente asociada a infección por estos virus. Un programa destinado a controlar exitosamente esta patología debe incluir elementos diagnósticos que permitan conocer la realidad nacional. Para detectar la presencia de estos virus en las mujeres de la II Región que asisten al Servicio de Oncología, Unidad de Patología cervical del Hospital Regional Dr. Leonardo Guzmán, se analizaron 83 muestras de exocervix, aplicando los criterios de Toki, para el diagnóstico histopatológico de infección por virus papiloma y la técnica de inmunoperoxidasa con complejo Avidina Biotina para confirmar la presencia de antígenos virales. La positividad obtenida fue de 32.53 por ciento y se presentó de preferencia en las lesiones intraepiteliales escamosas de bajo grado

Comparison of an IgM capture ELISA with a dot enzyme immunoassay for laboratory diagnosis of dengue virus infections.

This study describes the use of an IgM capture ELISA using cell culture derived antigens and a polyclonal rabbit antiflavivirus antisera for the detection of dengue positive cases. The IgM capture ELISA is compared with the dot enzyme immunoassay and the results are discussed in the context of dengue endemicity.

Two competitive enzime immunoassays for the detection of IgG class antibodies to hepatitis a antigen

Foram desenvolvidos dois ensaios imunoenzimáticos (EIA) competitivos: no primeiro (COMP-1) colocou-se numa placa sensibilizada com anti-HASV IgG as amostras teste juntamente como antígeno HAV e aseguir o conjugado anti-HAV HRP; no segundo (COMP-2), as amostras teste e o conjugado anti-HAV competem pelos epitopos do antígeno HAV previamente absorvido na placa sensibilizada do anti-HAV IgG. O substrato utilizado foi tetrametilbenzidina (TMB). Ambas as técnicas mostraram ser produtíveis e aplicáveis para fins de diagnóstico e pesquisa

Aspectos da padronizacao de testes sorologicos para a doenca de Chagas: um teste imunoenzimatico para a triagem de doadores de sangue / Standardization of serological tests for Chagas disease: an immunoenzymatic test for blood donors triage

No diagnostico sorologico da doenca de Chagas podem ser encontradas acentuadas divergencias mesmo entre laboratorios de grande experiencia. Para a padronizacao de um teste imunoenzimatico destinado primariamente a selecao de doadores de sangue foram cuidadosamente escolhidos paineis de soros que se buscaram como representativos das populacoes de chagasicos e de nao chagasicos. Produzido para maxima sensibilidade e estabilidade, o novo reagente (bioElisa - cruzi) foi testado em 1648 soros, com diagnostico clinico de doenca de Chagas em 219 e de outras afeccoes em 104. O teste foi comparado com testes ja bem padronizados, de imunofluorescencia (IF) e de hemaglutinacao (HA), em 1325 doros. O limiar de reatividade (cut off), estabelecido como ideal, foi indicado nos testes pela absorbancia de um soro de reatividade minima. A sensibilidade do teste imunoenzimatico foi de 0,9954 e a especificidade, como conegatividade, de 0,9969. Nao foram vistos resultados falso-positivos em casos de sifilis, toxoplasmose, mononucleose e de soros com altos titulos de anti-estreptolisina 0, mas foram encontrados em 5 de 15 casos de leishmaniose tegumentar, 10 de 24 casos de calazar, 1 de 15 casos de artrite reumatoide e 1 de 12 casos de lupus eritematoso sistemico....

Detección de chlamydia trachomatis en muestras endocervicales por un método rápido de ensayo inmunoenzimático / Detection of chlamydia trachomatis in endocervical samples by a quickly method of inmunoenzimatic essay

Se evaluó la utilidad de un método rápido de ensayo inmunoenzimático (TestPack, Chlamydia, Abbott Laboratories), en comparación con la técnica de cultivo celular, para la detección de Chlamydia trachomatis de muestras endocervicales obtenidas de 120 mujeres provenientes d dos poblaciones de Santiago. La sensibilidad global del ensayo inmunoenzimático fue 88,9% y su especificidad 99,1%. Los valores predictivos positivo y negativo fueron 90 y 99,1% respectivamente. En síntesis, la técnica evaluada demostró ser muy simple y rápida de realizar y de alta especificidad. No obstante, su sensibilidad inferior al cultivo celular, permite sugerir su uso en pacientes sintomáticos o población femenina de alto riesgo de infección por C. trachomatis