Leptospira interrogans insoluble fraction as a potential antigen source for lateral flow immunochromatography

BACKGROUND Leptospirosis is an emerging zoonosis that affects humans and animals. Immunochromatography rapid test is widely used for early diagnosis of leptospirosis, but with low sensitivity and specificity. OBJECTIVES To evaluate Leptospira interrogans insoluble fraction as a potential antigen source for lateral flow immunochromatography. METHODS Insoluble fraction derived from the crude bacterial extract was obtained by serial centrifugation. The polypeptide profile was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Immune reactivity of this fraction was assessed by Western Blotting and lateral flow immunochromatography (LFI). It was tested 160 microagglutination test (MAT)-positive sera from patients in the acute phase, 100 MAT-negative sera from patients with acute febrile illness, and 45 patients with other infectious diseases. FINDINGS There was a predominance of low molecular mass-polypeptide bands, ranging from 2 to 37 kDa. The antibody reactivity of theses polypeptides was found to range from 13-50%, especially between 10 and 38 kDa. Among MAT-positive sera of patients with leptospirosis in the acute phase, 97% were also positive in LFI, indicating high sensitivity. Among MAT-negative sera, all were negative in LFI, indicating high specificity. Only 2% of cross-reactivity was detected. CONCLUSION The insoluble fraction can be a valuable antigen source for development of point-of-care diagnosis test for leptospirosis.

Hepatitis B chronic infection among pregnant women attending the antenatal care in Bor State Referral Hospital, South Sudan

Introduction: Hepatitis B virus (HBV) is a major public health problem affecting 400 million people worldwide, and is a common cause of chronic liver failure (cirrhosis) and hepatocellular carcinoma. Sixty-eight percent of infected people are from the African and Pacific regions. Vertical transmission from mother to newborn baby is one of the mechanisms by which chronic hepatitis virus infection spreads, besides infections from contaminated needles and syringes and sexual contact. Hepatitis B chronic infection is endemic in many poor countries, especially in Africa. Method: A cross-sectional study was conducted between July and August 2021. Pregnant women attending the antenatal care (ANC) in Bor State referral hospital, South Sudan, were interviewed to collect information on their socio-demographic characteristics and risk factors for hepatitis B infection. The objective was to determine the seroprevalence of hepatitis B chronic infection through blood testing. Prevalence ratios for certain risk factors were calculated. Results: Two hundred pregnant women were enrolled. The Prevalence Rate for chronic infection with hepatitis B virus, diagnosed using the rapid immune-chromatographic assay for Hepatitis B surface antigen (HBsAg), was 8.5%. (95% CI; 4.7% - 12.3%). None of the suspected risk factors studied were found to be significantly associated with testing positive for HBV, except for a history of previous jaundice. Conclusion: The prevalence of HBV chronic infection among pregnant women in Bor, Jonglei State, is high hence there is a need for established public health interventions that can lead to a reduction of HBV vertical transmission. Treatment of pregnant women with HBV chronic infection using anti-viral medications during pregnancy might curb the vertical transmission rates.

Evaluation and influencing factor analysis of the detection effect of hepatitis B virus surface antigen and treponema pallidum using rapid screening immunochromatography technology / 中国输血杂志

【Objective】 To evaluate the effectiveness of rapid initial screening using HBsAg and syphilis reagents of immunochromatography technology before blood donation, and explore the influencing factors. 【Methods】 The pre-donation screening of HBsAg and anti-TP and post-donation blood test results of blood donors in Yangzhou region from January 2020 to June 2023 were retrospectively analyzed. The HBsAg and anti-TP reactive samples by ELISA from January to June 2023 were, retested using colloidal gold immunochromatographic reagents, and the results were compared and analyzed. 【Results】 A total of 200 414 blood donors were screened, among which 781 were HBsAg and anti-TP positive, accounting for 0.39%. A total of 191 717 blood donors successfully donated blood, and 986 were HBsAg and anti-TP positive by ELISA, accounting for 0.51%. 62 HBsAg and 61 anti-TP reactive samples were retested using the initial screening reagent, with 24 HBsAg reactive samples and 26 anti-TP reactive samples, accounting for 38.71% and 42.62% respectively. 14 HBsAg and 6 anti-TP gray area samples were retested, but no reactivity was found.The reactivity rates of 9 samples with HBsAg detection S/CO values greater than 25.0 and 10 samples with anti-TP detection S/CO values greater than 15.0 were all 100%.There was a negative correlation between the reaction intensity (S/CO value) of reactive samples and interpretation time of initial screening reaction. 【Conclusion】 The rapid primary screening of hepatitis B and syphilis with immunochromatography technology among blood donors can effectively improve the quality of blood and the qualification rate of blood after collection. Through targeted training of primary screening staff, the quality of primary screening can be further improved, the rate of missed detection can be reduced, and costs can be saved, thus reducing the risk of transfusion transmitted infection and ensuring the health of blood donors.

RAPID DIAGNOSIS OF VIRAL DIARRHEA IN CHILDREN UNDER 5 YEARS, TO STRENGTHEN THE EXISTING ADD PROGRAM

RAPID DIAGNOSIS OF VIRAL DIARRHEA IN CHILDREN UNDER 5 YEARS, TO STRENGTHEN THE EXISTING ADD PROGRAM Original Research Paper Sornajeyanthi P* M.D., Professor, Department of Microbiology, Tirunelveli Medical College, Tirunelveli - 627011, Tamil Nadu, India *Corresponding Author X 67GJRA - GLOBAL JOURNAL FOR RESEARCH ANALYSIS Background: Gastroenteritis in childhood is one of the most prevailing cause of morbidity and mortality across the globe. Rotavirus is the most common etiological agent among viruses causing gastroenteritis in children below ?ve years. Adenovirus has been evidenced as the second most common cause of childhood gastroenteritis in certain parts of the world. The present study was conducted to estimate the incidence of Rotavirus and Adenovirus among diarrhoeal cases in children under 5 years of age. A total of 40 children younger than 5 years of age Materials and methods: suffering from acute diarrhoea were included in the present study. A total of 40 samples were collected and analyzed for Rotavirus and Adenovirus using commercially available Immunochromatography kit. The prevalence of Rotavirus and Results: Adenovirus was found to be 7.5% and 2.5% respectively among children under ?ve years of age with acute diarrhoeal disease. Conclusion: The disease burden of Rota viral illness has decreased due to increased coverage of Rotavirus vaccination through inclusion in National immunization schedule and thus effective and ef?cient vaccination coverage is fundamental rationale in the process of strengthening of Acute Diarrhoeal Disease(ADD) program

Virus de la leucemia e inmunodeficiencia felina: un estudio retrospectivo en clínicas veterinarias particulares en Bogotá y Chía (Colombia), 2015-2019 / Leukemia viruses and feline immunodeficiency: a retrospective study in private veterinary clinics in Bogotá and Chía (Colombia), 2015-2019

Resumen Los virus de inmunodeficiencia y leucemia felina representan un problema de gran envergadura para los felinos domésticos debido a la multiplicidad de sintomatologías que manifiestan. El objetivo del presente estudio fue establecer, retrospectivamente, la prevalencia en la presentación de ViLeF y VIF en pacientes de seis clínicas de pequeños animales en Bogotá y Chía, en relación con factores como su edad, raza y género. Se realizó un estudio transversal y retrospectivo, mediante la recopilación de datos de 1.014 historias clínicas de pacientes felinos que ingresaron a seis clínicas de la ciudad de Bogotá y Chía, para determinar la prevalencia de VIF y ViLeF y la asociación de estas con factores como edad, género y raza, entre 2015 y 2019, a través de la prueba OR. La detección de los virus se realizó mediante una prueba rápida basada en inmunocromatografía. La mayor prevalencia para cada enfermedad por año fue: 12,3% para VIF en 2012 y 18% para ViLeF en 2019. Los machos presentaron mayores seroprevalencias para ambas enfermedades durante la mayoría los años evaluados. Factores como raza (criolla: VIF: 1,85; ViLeF: 2,01), género (macho: VIF: 1,53 OR; ViLeF: 1,64) y edad (> 7 años: VIF: 3,82; ViLeF: 3,21) se relacionaron positivamente con la presentación de ambas enfermedades en la población felina evaluada.

Abstract Immunodeficiency virus and feline leukemia virus represent major problems for domestic felines due to the multiplicity of symptoms they manifest. The objective of the present study was to establish, retrospectively, the prevalence in the presentation of FeLV and FIV in patients from six small animal clinics in Bogota and Chia, related to factors such as age, race, and gender. A cross-sectional and retrospective study was carried out, collecting data from 1.014 clinical records of feline patients who were admitted to six clinics in the city of Bogota and Chia, to determine the prevalence of FIV and FeLV and their association with factors such as age, gender, and race, between 2015 and 2019 through the OR test. The detection of the viruses was carried out through a rapid test based on immunochromatography. The highest prevalence for each disease per year was 12,3% for FIV in 2012 and 18% for FeLV in 2019. Males presented higher seroprevalences for both diseases during most of the years evaluated. Factors such as race (Creole: FIV: 1,85; FeLV: 2,01), gender (male: FIV: 1.53 OR, FeLV: 1,64), and age (> 7 years: FIV: 3.82; FeLV: 3.21) were positively related to the presentation of both diseases in the feline population evaluated.

Frecuencia de la leucemia felina (ViLeF) en un refugio municipal de Rionegro, Colombia, durante 2020 / Frequency of Feline Leukemia (FeLV): Municipal Shelter Rionegro, Colombia 2020

RESUMEN La leucemia viral felina (ViLeF) es una enfermedad retroviral letal, de una elevada prevalência en Colombia, que afecta a felinos de diferentes edades y sexos. El objetivo de esta investigación fue determinar la frecuencia por serodiagnóstico de ViLeF en felinos del centro integral de bienestar animal Ceiba, ubicado en Rionegro, Antioquia (Colombia), en 2020. Para ello, se realizó un estudio descriptivo longitudinal de serofrecuencia de ViLeF desde enero hasta diciembre de 2020. Fueron muestreados 92 gatos, a los cuales se les efectuó una prueba p27 por inmunoensayo comercial Elisa (Idexx©, Snap Combo Plus®, Maine, EE. UU.). La frecuencia de felinos positivos fue 30/92 (32,60%) y el mes de mayo fue el de mayor frecuencia (9,78%). Los machos positivos fueron 17/92 (18,47%) y las hembras 13/92 (14,13%). La edad promedio de seropositividad fue 2,14 años. La frecuencia de ViLeF en 2020 para Ceiba, Rionegro (Colombia) es de 32,60%, un valor elevado con respecto a descripciones en otros albergues para felinos. ViLeF es una enfermedad que está siendo reportada con mayor frecuencia en Colombia, debido a que las medidas de prevención no se están adoptando rutinariamente.

ABSTRACT Feline viral leukemia (ViLeF) is a lethal retroviral disease with a high prevalence in Colombia that affects felines of different ages and sexes. The purpose of this investigation was to determine the frequency by serodiagnosis of ViLeF in felines of the integral center of animal welfare Ceiba, located in Rionegro, Antioquia (Colombia), during 2020. For that, a longitudinal descriptive study of ViLeF serofrequency from were made January to December 2020. 92 cats were sampled, which were tested for p27 by commercial Elisa immunoassay (Idexx©, Snap Combo Plus®, Maine, USA). The frequency of positive felines was 30/92 (32,60%). May was the month with the highest frequency (9,78%). The positivity frequency for males was 17/92 (18,47%) and the frequency for females 13/92 (14,13%). The main age of seropositivity was 2,14 years. The frequency of ViLeF in 2020 for Ceiba, Rionegro (Colombia) is 32,60%. This is a high value in comparison to descriptions in other shelters for felines. ViLeF, in Colombia, is a disease that has been reported with more frequency because prevention measures are not being adopted routinely.

Development of a colloidal gold based immunochromatographic strip for 8-OHdG detection / 生物工程学报

8-hydroxy-2'-deoxyguanosine (8-OHdG) is a sensitive and stable biomarker for evaluating DNA oxidative damage. A rapid and sensitive colloidal gold immunochromatographic strip was developed for 8-OHdG detection by a competitive method. The sample pad (glass cellulose film), bonding pad (glass cellulose film), nitrocellulose film and absorbent pad were pasted on the polyvinyl chloride (PVC) base plate to construct the test strip. Colloidal gold (AuNPs) was prepared by the reduction of chloroauric acid with sodium citrate. 8-OHdG antibody (Ab) was coated on the outer layer of AuNPs to form Ab@AuNPs as a probe. Bovine serum albumin (BSA) and 8-OHdG were conjugated with carbodiimide hydrochloride to prepare an artificial antigen, which was used as the coating antigen of detection line. Goat anti mouse polyclonal antibody IgG was used as the coating antibody of control line. The experimental parameters were optimized including the type of nitrocellulose membrane, the formula of loading solution, and the spraying amount of gold labeled antibody. The results showed that the appropriate nitrocellulose membrane was CN 95. The optimal loading solution included BSA (1%), Tween-20 (3%), sucrose (3%) and NaCl (0.9%). The optimal spraying amount of gold labeled antibody was 4 μL. 8-OHdG can be detected by the strip under visible light, and the level of 8-OHdG in urine can be preliminarily determined by comparing the color intensity of T line and C line. The 8-OHdG concentration in urine was further calculated by the gray value of T line and the threshold of detection was 2.55 μg/L. This colloidal gold immunochromatographic strip is simple, rapid and specific for detecting 8-OHdG in human urine to preliminarily evaluate the human status.

Antigenemia temprana de Cryptococcus en pacientes asintomáticos VIH positivos en Barranquilla, Colombia / Cryptococcus early antigenemia in HIV positive asymptomatic patients in Barranquilla, Colombia

Resumen La criptococosis meníngea presenta alta mortalidad mundial, especialmente en población VIH/sida. La OMS recomienda detectar el antígeno capsular de Crypto coccus como estrategia para un diagnóstico temprano y poder minimizar complicaciones. Objetivo: realizar antigenemia temprana de Cryptococcus mediante in munocromatografía/ensayo de flujo lateral en pacientes asintomáticos VIH+. Material y método: estudio descriptivo observacional; entre julio-2016 y mayo-2019 se procesaron mediante ensayo de flujo lateral, muestras de suero de 169 pacientes asintomáticos VIH+, con CD4 ≤120 cel/μL en Barranquilla, Colombia. Ante resultado positivo, se indicó profilaxis con fluconazol; se hizo seguimiento a todos los casos. Resultados: la antigenemia fue positiva en cinco pacientes (2,96%); uno falleció, cuatro recibieron profilaxis y la prueba se negativizó en dos. Los pacientes con resultado negativo inicial no desarrollaron durante el estudio sinto matología compatible con esta micosis. Discusión: el ensayo de flujo lateral de Cryptococcus está recomendado para el diagnóstico temprano de la criptococosis en población VIH/sida. Conclusión: detectar tempranamente el antígeno circulante de Cryptococcus mediante ensayo de flujo lateral en pacientes asintomáticos VIH+, permitió instaurar profilaxis oportuna, hacer seguimiento y control para reducir la mortalidad asociada con la criptococosis meníngea.

Abstract Meningeal cryptococcosis presents high levels of global mortality, especially in the HIV/AIDS population. The WHO recommends detecting the capsular antigen as an important strategy for early diagnosis and be able to minimize complications. Objective: Perform early cryptococcal antigenemia by immunochromatographic/ lateral flow assay in asymptomatic HIV+ patients. Material and method: descriptive observational study; between July-2016 and May-2019, serum samples from 169 asymptomatic HIV+ patients with CD4 ≤120 cells/μL were processed by lateral flow assay in Barranquilla, Colombia. Given a positive result, prophylaxis with fluconazole was indicated; all cases were followed up. Results: antigenemia was positive in five (2.96%) patients; one died; four received prophylaxis, and the test turned negative in two. The patients with an initial negative result, did not developed symptoms compatible with this mycosis during the study period. Discussion: lateral flow assay for Cryptococcus is recommended for the early diagnosis of cryptococcosis in the HIV/AIDS population. Conclusion: early detection of circulating Cryptococcus antigen by lateral flow assay in HIV+ patients allowed the establishment of timely prophylaxis, follow-up, and control to reduce mortality associated with meningeal cryptococcosis.

Hábitos alimentarios y de higiene asociados a la seroprevalencia de Helicobacter pylori en estudiantes universitarios peruanos / Dietary and hygiene habits associated with the Helicobacter pylori seroprevalence in Peruvian university students / Hábitos alimentares e de higiene associados à soroprevalência do Helicobacter pylori em estudantes universitários peruanos

RESUMEN Introducción: La infección por Helicobacter pylori es cada vez más frecuente en los jóvenes peruanos e incrementa su riesgo de padecer neoplasias gástricas. Objetivo: Determinar los hábitos alimentarios y de higiene asociados a la seroprevalencia de infección por Helicobacter pylori en estudiantes universitarios del departamento de Cajamarca, Perú, durante los meses de septiembre a octubre de 2019. Método: Estudio observacional, transversal, prospectivo con un diseño no experimental. La población estuvo conformada por 367 estudiantes de la carrera profesional de Tecnología Médica. El tamaño de la muestra fue de 188 estudiantes de ambos géneros. Se detectaron anticuerpos IgG frente a Helicobacter pylori en suero, mediante el método de inmunocromatografía. Los hábitos alimentarios y de higiene se recopilaron utilizando una encuesta estructurada. Resultados: El 51,1 % de estudiantes presentó anticuerpos IgG frente a Helicobacter pylori. El 31,38 % de los estudiantes que consumía "a veces" alimentos elaborados en la calle resultaron seropositivos a Helicobacter pylori. Aquellos estudiantes que manifestaron lavarse las manos "a veces" (29,79 %) y "siempre" (21,28 %) antes de ingerir los alimentos presentaron anticuerpos IgG contra la bacteria. Además, los estudiantes seropositivos frente a Helicobacter pylori lavaban sus frutas y verduras con el agua del grifo (43,62 %) y consumían agua de grifo no tratada (29,79 %). Conclusión: El consumo de alimentos preparados en la calle, lavado de manos antes de consumir alimentos, tipo de agua para consumo y lavado de frutas y verduras antes de ingerirlas son hábitos alimentarios y de higiene asociados a la seroprevalencia de Helicobacter pylori.

ABSTRACT Introduction: Helicobacter pylori infection is becoming more frequent in the young population of Peru and at the same time increases the risk of gastric neoplasms. Objective: To identify the dietary and higiene habits associated with the seroprevalence of Helicobacter pylori infection in university students at the Cajamarca Department. Assesed period from September throughout October 2019. Method: An observational, cross-sectional, prospective study with a non-experimental design was carried out. A population of 367 students on Medical technology career were involved and 188 of them, in both sex, were selected as trial. It was detected, using the immunochromatography method in serum assay, IgG antibodies against Helicobacter pylori. Dietary and hygiene habits were collected using a well-structed enquiry. Results: It was identified IgG antibodies against Helicobacter pylori infection in 51.1% of students. The 31.38% of those who, not frequently, had consumed food prepared outdoors were seropositive for Helicobacter pylori. Those students who revealed wash their hands, not frequently (29.79%) and frequently (21.28%) before eating, produced antibodies against this bacterial infection. In addition, Helicobacter pylori seropositive students washed their fruits and vegetables with obtained water from the tap (43.62%) and consumed untreated water fom the tap too (29.79%). Conclusions: Food intake outdoors, wash of hands, fruits and vegetables before eating, and the quality of water to be consumption are dietary and hygiene habits associated with the Helicobacter pylori seroprevalence.

RESUMO Introdução: A infecção por Helicobacter pylori é cada vez mais comum em jovens peruanos e aumenta o risco de neoplasias gástricas. Objetivo: Determinar os hábitos alimentares e de higiene associados à soroprevalência da infecção por Helicobacter pylori em universitários do departamento de Cajamarca, Peru, durante os meses de setembro a outubro de 2019. Método: Estudo observacional, transversal, prospectivo com um não experimental. A população foi composta por 367 alunos da carreira de Tecnologia Médica. O tamanho da amostra foi de 188 alunos de ambos os sexos. Os anticorpos IgG contra Helicobacter pylori foram detectados no soro pelo método de imunocromatografia. Os hábitos alimentares e de higiene foram coletados por meio de questionário estruturado. Resultados: 51,1% dos alunos apresentaram anticorpos IgG contra Helicobacter pylori. 31,38% dos alunos que comeram "às vezes" alimentos preparados na rua eram soropositivos para Helicobacter pylori. Os alunos que relataram lavar as mãos "às vezes" (29,79%) e "sempre" (21,28%) antes de comer apresentaram anticorpos IgG contra a bactéria. Além disso, os alunos soropositivos para Helicobacter pylori lavavam frutas e vegetais com água da torneira (43,62%) e consumiam água da torneira não tratada (29,79%). Conclusão: O consumo de alimentos preparados na rua, a lavagem das mãos antes de consumir os alimentos, o tipo de água para consumo e a lavagem de frutas e verduras antes de ingeri-los são hábitos alimentares e de higiene associados à soroprevalência do Helicobacter pylori.

A Review on COVID-19 Diagnosis Tests Approved for Use in Brazil and the Impact on Pandemic Control

Abstract With the COVID-19 pandemic, many diagnostic tests (molecular or immunological) were rapidly standardised, given the urgency of the situation, many are still in the process of being validated. The main objective of this study was to review the aspects of the diagnostic kits approved in Brazil and their application in the different federative units to gather epidemiological information. In order to achieve these objectives, a survey was carried out on the data available at the regulatory agency (ANVISA) and in the literature. The main countries that have registered products in Brazil are China (51.4%), Brazil (16.6%), South Korea (9.2%), USA (8.8%) and Germany (3.6%). The methodologies of these products are based on the detection of nucleic-acid (15.8%), antigen (13%) and antibody (71.2%). In the immunological tests, it was verified that the sensitivity ranged from 55 to 100% and the specificity from 80 to 100%. The percentage of cases in the samples tested in Brazil is elevated in almost all federative units since eight states showed 40% of positive cases in tested samples, while 18 states displayed between 20 and 40%. In conclusion, this review showed that Brazil is dependent on external technology to respond to pandemics, epidemics and endemics disease and needs to improve its biotechnological scheme to solve further diseases outbreaks.

Establishment and performance evaluation of a quantitative detection method for immunoglobulin G4 based on fluorescence immunochromatography / 中华胰腺病杂志

Objective:To establish a rapid and quantitative method for the determination of immunoglobulin G4 (IgG4) by fluorescence immunochromatography and to analyze its clinical application value.Methods:Fluorescence immunoassay for quantitative detection of IgG4 was obtained by means of preparation of kits in a competitive reaction mode and combining immunoassay with fluorescence quantitative assay. The linearity, precision, accuracy, anti-interference ability and stability of the method were evaluated, and compared with immune-scattering turbidimetry, receiver operating characteristic curve (ROC) was plotted, area under the curve (AUC) was calculated, and the critical value for the diagnosis of pancreatitis related diseases was determined, and sensitivity and specificity were calculated.Results:The linear range of fluorescence immunoassay for IgG4 was 0.2-10.0 g/L. The accuracy coefficient of variation was less than 15%, and the accuracy deviation was within ±15%. Bilirubin (2.5 g/L), triglyceride (10 g/L) and hemoglobin (10 g/L) had no significant effect on the quantitative determination. Within 14 months, 1.20 g/L and 2.65 g/L reference samples were detected with concentration deviations within ±15%. The kit validity period was >12 months. Serum samples of 200 healthy people were detected by fluorescence immunochromatography, and the normal reference value of IgG4 was <2.03 g/L. fluorescence immunochromatography and Immunoturbidimetry were used to detect IgG4 concentrations in 383 clinical serum samples. The results showed that the two methods were consistent ( P>0.05). Using 2.01g/L IgG4 as the critical value, the sensitivity and specificity of fluorescence immunochromatography were 96.3% and 95.5% by ROC curve analysis, respectively. Conclusions:Fluorescence immunochromatography was a simple, rapid and accurate method for the quantitative detection of IgG4, and had high sensitivity and specificity for the diagnosis of pancreatitis related diseases. It was suitable for quantitative detection of bulk samples in outpatient and emergency departments.

Comparison of the Consistency and Difference of Three Detection Methods in Blood Concentration Monitoring of Mycophenolic Acid / 中国药房

OBJECTIVE：To investigate the consistency and difference of f luorescence immunochromatographic and liquid chromatography-tandem mass spectrometry （LC-MS/MS）and enzyme multiplied immunoassay technique （EMIT）in the blood concentration monitoring of mycophenolic acid. METHODS ：Fluorescence immunochromatography ，LC-MS/MS and EMIT were used to detect the blood concentration of mycophenolic acid in 61 blood samples of children treated with mycophenolate mofetil ester orally at different time points. Kolmogorov-Smirnov method ，Wilcoxon pairing test ，Passing-Bablok regression ，Cusum method，Spearman correlation analysis ，Bland-Altman scatter diagram were adopted for statistical analysis. RESULTS ：Blood concentrations of mycophenolic acid ，which were determined by fluorescence immunochromatography ，LC-MS/MS and EMIT ， showed non-normal distribution. Passing-Bablok regression analysis showed that regression equation of fluorescence immunochromatography and LC-MS/MS ，fluorescence immunochromatographic method and EMIT were CFI=0.928 3CLC-MS/MS+0.961 7 and CFI＝0.880 7CEMIT－0.488 2（FI means fluorescence immunochromatographic ）. Spearman correlation analysis showed that the correlation coefficients between fluorescence immunochromatography and LC-MS/MS ，fluorescence immunochromatography and EMIT were 0.968 and 0.929， respectively （P＜0.000 1）. Bland Altman scatter plot analysis showed that 3.28％ of the 358341451@qq.com difference between fluorescence immunochromatography and LC-MS/MS was outside the consistency limit （±1.96SD）， and 1.64％ of the difference between fluorescence immuno- chromatography and EMIT was outside the consistency limit （± 1.96SD）. Wilcoxon pairing test showed that the results of fluorescence immunochromatography were higher than those of LC-MS/MS （Z＝3.76，P＝0.000 2）and lower than those of EMIT （Z＝－5.96，P＜0.000 1）. CONCLUSIONS ：Fluorescence immunochromatography shows good consistency and correlation with LC-MS/MS and EMIT ；the blood concentrations of mycophenolic acid detected by fluorescence immunochromatography were higher than those by LC-MS/MS and lower than those by EMIT . It can be used for bedside rapid detection. When using the test results of different methods for clinical medication ，the differences of test methods need to be considered.

Establishment of fluorescence immunochromatography detection for cytoskeleton-associated protein 4 / 生物工程学报

A rapid and simple method to detect tumor markers in liver cancer was established by combining immunochromatography technique with fluorescent microsphere labeling. According to the principle of double antibody sandwich, the cytoskeleton-associated protein 4 (CKAP4) paired antibody was used as the labeled and coated antibody, and the goat anti-rabbit polyclonal antibody was used as the quality control line coated antibody in the preparation of the CKAP4 fluorescent immunochromatographic test strips. After the preparation, the test strips were evaluated on various performance indicators, such as linearity, precision and stability. The CKAP4 immunochromatographic strip prepared by time-resolved fluorescent microspheres had high sensitivity, and good specificity. Its precision was within 15%, recovery between 85% and 115%, and linear range between 25 and 1 000 pg/mL. The test strip could be kept stable at 37 °C for 20 days, and it correlated well with commercial ELISA kits. The CKAP4 fluorescence immunochromatography method can quantitatively detect the content of CKAP4 in serum. Furthermore, it is rapid, sensitive, simple, economical and single-person operation. This method has the potential of becoming a new method for the diagnosis and treatment of liver cancer.

Performance of urea-mediated dissociation in reducing false-positive of 2019-nCoV IgM test / 中华检验医学杂志

Objective@#To investigate the interference factors causing false-positive result of novel coronavirus IgM antibody (SARS-CoV-2 IgM) detected by gold immunochromatography assay (GICA) and enzyme-linked immunosorbent assay (ELISA).@*Methods@#A total of 71 serum from different pathogen infections and related chronic diseases patients were collected from the Affiliated Hospital of North Sichuan Medical College from January 25, 2020 to February 15, 2020. GICA and ELISA were used to detect 2019-nCoV IgM in 71 serum, including 5 influenza A virus (Flu A) IgM positive serum, 5 influenza B virus (Flu B) IgM positive serum, 5 Mycoplasma pneumonia (MP) IgM positive serum, 5 Legionella pneumophila (LP) IgM positive serum, 29 rheumatoid factor (RF) IgM positive serum, 5 hypertension patients serum, 5 diabetes mellitus patients serum, 6 human immunodeficiency virus (HIV) infection patients serum and 6 Corona Virus Disease 2019 (COVID-19) patients serum. The interference factors causing false positive results of the two methods were analyzed, and urea dissociation test was employed to dissociate the 2019-nCoV IgM positive serum using the best dissociation concentration. Statistical analyses were performed by SPSS, version 19.0.@*Result@#s 2019-nCoV IgM was positive in 18 cases of middle-high level RF-IgM positive serum and 6 cases of 2019-nCoV-infected serum detected by two methods, and the other 47 serum were negative. When the dissociation concentration of urea was 6 mol/L, 2019-nCoV IgM was negative in 17 cases of middle-high level RF-IgM positive serum and positive in 6 cases of 2019-nCoV-infected serum detected by GICA. When the urea dissociation concentration was 4 mol/L, dissociation time was 10 min and the avidity index<0.46 was set as negative, 2019-nCoV IgM was negative in 15 cases of middle-high level RF-IgM positive serum and positive in 6 cases of 2019-nCoV-infected serum detected by ELISA.@*Conclusion@#The middle-high level of RF-IgM could cause false positive results of SARS-CoV-2 IgM detected by GICA and ELISA, and the urea dissociation test would be helpful for reducing the probability of false-positive results of SARS-CoV-2 IgM test.

Performance Evaluation of Two Immunochromatographic Assays for Rotavirus Detection in Stool Specimens

BACKGROUND: Rotavirus is a major pathogen causing enteritis worldwide in children under five years of age. In recent years, immunochromatographic assay (ICA) has been widely used as a diagnostic test for rotavirus detection. This study aimed to compare and evaluate the performance of ICA-based rotavirus rapid test kits from two manufacturers. METHODS: Residual stool samples from a total of 130 children with acute enterocolitis from November 2017 to January 2018 were used. We compared the results of the two immunochromatographic methods (SD BIOLINE Rotavirus kit and GENEDIA Rotavirus Ag Rapid Test) with those of the currently used enzyme immunoassay method. RESULTS: Positive agreement, negative agreement, and total agreement rates between the SD BIOLINE rotavirus kit and the enzyme immunoassay were 98.0%, 100%, and 99.2%, respectively. Positive agreement, negative agreement, and total agreement rates between the GENEDIA Rotavirus Ag Rapid Test and the enzyme immunoassay were 96.0%, 100%, and 98.4%, respectively. CONCLUSIONS: Both rotavirus rapid test kits showed very good agreement with the conventional enzyme immunoassay. Therefore, it could be a useful test to detect rotavirus directly from stool samples in a short time.

Development and application of monoclonal antibodies anti-human lipoprotein-associated phospholipase A2 / 生物工程学报

The aim of this study is to prepare monoclonal anti-human Lp-PLA2 antibodies, and establish a rapid and accurate immunochromatographic Lp-PLA2 assay used in community medical institution. The gene sequence of human Lp-PLA2 was obtained from NCBI to construct the expression plasmid. Lp-PLA2 protein expressed in CHO-K1 cells was used to immune BALB/c mice. The monoclonal antibodies were produced in mouse ascites after hybridoma cells screening. Antibodies were evaluated by SDS-PAGE, ELISA and other methods. The Lp-PLA2 test strip was prepared based on sandwich method and evaluated with the portable detection instrument. The affinity of the paired antibodies, PLA1 and PLA5, both reached 1×10⁻⁸. The antibody subclass was IgG1. Both antibodies recognized the Lp-PLA2 protein in the blood specifically. The Lp-PLA2 test strip was prepared based on sandwich method, with linear range of 20-2000 ng/mL. The Lp-PLA2 test strip correlated well with the diaDexus ELISA test kit. In conclusion, the paired antibodies were successfully prepared with high affinity and specificity. The immunochromatographic test of Lp-PLA2 provided a fast and accurate method to detect the concentration of Lp-PLA2 in blood sample for clinical use in the community medical institution and could contribute to the management of cardiovascular diseases.

Colloidal gold immunochromatographic strip for rapid detection of Haemophilus influenzae / 生物工程学报

To establish a novel colloidal gold immunochromatography assay (GICA) for rapid, sensitive and accurate detection of Haemophilus influenzae infection by using the outer membrane protein P6 as detection target. First, the linear antigen epitope located in the extracellular domain of the P6 protein (GenBank accession number: AGH02799) was predicted by bioinformatics analysis. The region (62-75 aa of the protein) with strong antigen specificity was chosen and synthesized. Two rabbits were then immunized by the polypeptides (14 aa) for production of polyclonal antibodies. Then, the recombinant P6 proteins were also obtained to produce polyclonal antibodies. Finally, based on the two antibodies, a novel colloidal GICA for detection of Haemophilus influenzae infection was established and the specificity, sensitivity, repeatability and stability of this method were evaluated. At the same time, the method was tested in clinical simulation, and the plate culture method was used to verify its accuracy. The test strip for Haemophilus influenzae infection was successfully prepared. The detection limit of the test strip was as low as 1×105 CFU/mL and the whole process can be completed within 15 minutes. The strip specifically recognized Haemophilus influenzae and did not react with nine of other common respiratory pathogens such as Streptococcus pneumoniae, Moraxella catarrhalis, Mycoplasma pneumonia, and Legionella pneumophila. And the strips could be stored at 25 °C for at least 6 months without losing sensitivity or specificity. The coincidence rate between the results of 200 clinical samples and the plate culture method was 90.5%. Haemophilus influenzae protein P6, which possessed a high degree of surface antigen accessibility and antigencity, could be used as a marker for Haemophilus influenzae detection. The immunochromatographic colloidal gold test strip which bears the features of rapidity, convenience and sensitivity provides a unique tool for the on-site surveillance and diagnosis of Haemophilus influenzae infection in clinical test.

Point-of-care testing in the diagnosis of infectious diseases / 中华检验医学杂志

Rapid diagnosis is important for the prevention and control of infectious disease.Point-of-care testing (POCT) technology is simple,mobile,rapid,sensitive and accurate.In recent years,POCT has been widely used in the detection of infectious agents.This article reviews the development of POCT in the diagnosis of infectious diseases,focusing on immuno-chromatographic technology,microfluidic chip technology and loop-mediated isothermal amplification (LAMP) technology.

Evaluation of a Rapid Diagnostic Antigen Test Kit Ribotest Mycoplasma® for the Detection of Mycoplasma pneumoniae

PURPOSE: Early detection of Mycoplasma pneumoniae is important for appropriate antimicrobial therapy in children with pneumonia. This study aimed to evaluate the diagnostic value of a rapid antigen test kit in detecting M. pneumoniae from respiratory specimens in children with lower respiratory tract infection (LRTI). METHODS: A total of 215 nasopharyngeal aspirates (NPAs) were selected from a pool of NPAs that had been obtained from children admitted for LRTI from August 2010 to August 2018. The specimens had been tested for M. pneumoniae by culture and stored at −70°C until use. Tests with Ribotest Mycoplasma® were performed and interpreted independently by two investigators who were blinded to the culture results. RESULTS: Among the 215 NPAs, 119 were culture positive for M. pneumoniae and 96 were culture negative. Of the culture-positive specimens, 74 (62.2%) were positive for M. pneumoniae by Ribotest Mycoplasma®, and 92 of the 96 (95.8%) culture-negative specimens were negative for M. pneumoniae by Ribotest Mycoplasma®. When culture was used as the standard test, the sensitivity and specificity of Ribotest Mycoplasma® were 62.2% and 95.8%, respectively. Additionally, the positive predictive value, negative predictive value, and overall agreement rates with Ribotest Mycoplasma® were 94.9%, 67.2%, and 77.2%, respectively. CONCLUSIONS: A positive test result of Ribotest Mycoplasma® suggests a high likelihood of culture-positive M. pneumoniae infection. However, a negative test result should be interpreted with caution because nearly one-third of negative test results reveal culture-positive M. pneumoniae infections.

Review of detection methods for neutrophil extracellular traps (NETs) / 中国药理学通报

Neutrophil extracellular trap nets (NETs) are complex networks of proteins and DNA. Many studies have shown that NETs are important participants in the pathophysiological processes of various immune inflammatory diseases, thrombosis, cancer and so on. The dynamic changes of NETs at each stage can predict the course of the disease to a certain extent. This article systematically reviews the current detection methods for ef-fectively quantifying NETs in order to provide the latest theoretical reference for the early detection of chronic inflammation and targeted therapy of cancer.