scholarly journals Assessment of humoral response to SARS-CoV-2 using an ELISA kit, developed and validated at references laboratories in Brazil

2021 ◽  
Author(s):  
Flávia Bagno ◽  
Luis Andrade ◽  
Sarah Sérgio ◽  
Maria Figueiredo ◽  
Lara Godoi ◽  
...  
Keyword(s):  
2021 ◽  
Author(s):  
Marcelo S. Conzentino ◽  
Karl Forchhammer ◽  
Emanuel M Souza ◽  
Fábio O. Pedrosa ◽  
Meri B. Nogueira ◽  
...  

AbstractSerological assays are important tools to identify previous exposure to SARS-CoV-2, helping to track COVID-19 cases and determine the level of humoral response to SARS-CoV-2 infections and/or immunization to future vaccines. Here the SARS-CoV-2 nucleocapsid protein was expressed in Escherichia coli and purified to homogeneity and high yield using a single chromatography step. The purified SARS-CoV-2 nucleocapsid protein was used to develop an indirect enzyme-linked immunosorbent assay for the identification of human SARS-CoV-2 seroconverts. The assay sensitivity and specificity were determined analyzing sera from 140 PCR-confirmed COVID-19 cases and 210 pre-pandemic controls. The assay operated with 90% sensitivity and 98% specificity; identical accuracies were obtained in head-to-head comparison with a commercial ELISA kit. Antigen coated plates were stable for up to 3 months at 4°C). The ELISA method described is ready to mass production and will be an additional toll to track COVID-19 cases.


Author(s):  
Salman Khan ◽  
Molly Madan

Objective:- Hepatitis B is noteworthy medical issues that may include the late continuation of liver cirrhosis and hepatocellular carcinoma. The present study aimed for the detection and diffrentiation of Hepatitis B virus HBsAg inactive non-replicative carriers, HBeAg-positive inactive replicative carriers, active carriers & HBeAg-negative chronic hepatitis B by Real Time PCR and their genotyping Methods: This research conducted on 245 positive for HBsAg, 118 (48.16 %) were male and 127 (51.84%) were female patients, which was performed in central research station labortory of Microbiology at netaji subhash Chandra Bose subharti Medical College and Hospital, Meerut Between march 2016 to November 2017 The sera were separated and screened for HBsAg by ELISA kit. Positive samples for HBsAg were tested for HBeAg ELISA kit and DNA Viral load then sequenced for genotying Results:. Of the 245 HBsAg Positive case 55 (1.12%) were HBeAg positive. In 16 PCR positive and HBV genotyping, In HBsAg inactive Non-Replicative 37.5% (n=6) genotype-B and 6.25% (n=1) genotype-A, In HBeAg inactive Replicative 12.5% (n=2) genotype-B and 12.5% (n=2) genotype-A and In HBeAg Active Chronic Hepatitis B 18.75% (n=3) genotype-B and 12.5% (n=2) genotype-A were detected Conclusions: Management strategy, using HBsAg, HBeAg and HBV DNA viral load, seems adequate for the confirmation and diffrentiation of Hepatitis B virus inactive, active carriers & HBeAg-negative chronic hepatitis B patients and genotype B was more prevalent in comparission to genotype A. Distribution of carriers & genotypes, help physicians to prescribe proper antiviral/interferon therapy according to current genotyping pattern in this region Keywords: Hepatitis B virus, Carrier State, HBsAg, HBeAg, RT-PCR


2020 ◽  
Vol 43 (1) ◽  
pp. 75-80
Author(s):  
Md Zulfekar Ali ◽  
Mohammad Moktader Moula ◽  
Zafar Ahmed Bhuiyan ◽  
Muhammad Tariq Javed

AbstractChicken astroviruses (CAstV) are enteric viruses of poultry causing gastroenteritis, malabsorption, gout and white chick disease commonly known as runting-stunting syndrome (RSS). It can affect the wide range of poultry birds, especially chicken, turkey and duck worldwide. To our best knowledge there is no published report on presence of antibodies against CAstV in Bangladesh. Therefore, the study aimed to detect the presence of CAstV antibodies in broilers and sonali chickens (a cross-bread) in Bangladesh through a cross-sectional survey. A total of 454 blood samples from 66 flocks of broiler (n=343) and sonali chickens (n=111) of different ages were obtained during 2017 from four districts. The birds were healthy but were not vaccinated against CAstV. The samples were tested for specific antibodies against CAstV Group B by using commercially available ELISA kit. Overall, 16.74% (76/454) samples and 34.84% (23/66) flocks were positive for CAstV antibodies. The seroprevalence of CAstV was significantly (p=0.001) higher in sonali chickens (36.96%) than broiler (10.20%), while it was significantly higher (p=0.001) in birds of Bogura district (36.94%) than the other three districts. Regarding the age groups, seroprevalence was insignificantly (p=0.192) higher in sonali chicken before laying age (45%) than during laying age (27.45%). Regarding the seasons, CAstV infection was prevalent significantly (p=0.001) higher in winter season. Thus, the present study indicated the presence of CAstV in poultry in Bangladesh, so further studies are required to find out the magnitude of the problem in the country.


2017 ◽  
Vol 68 (9) ◽  
pp. 2132-2134
Author(s):  
Daniela Roxana Albu (Matasariu) ◽  
Elena Mihalceanu ◽  
Alina Pangal ◽  
Carmen Vulpoi ◽  
Mircea Onofriescu ◽  
...  

Endometriosis is a multifactorial disease that is manifested by infertility and pelvic pain. The purpose of the study was to evaluate the effect of progesterone treatment on the serum level of osteopontin, a multipotent cytokine, in patients with endometriosis. The study was prospective and we evaluated osteopontin levels that were measured in the serum of 40 patients with endometriosis and 12 healthy women using a standardized Enzyme-Linked Immunosorbent Assay (ELISA) kit. Osteopontin seric levels were lower in endometriosis patients and increased after progesterone treatment. Because of the large dispersion of data even in the control group, we find the association between osteopontin and endometriosis questionable.


1977 ◽  
Vol 146 (2) ◽  
pp. 571-578 ◽  
Author(s):  
M E Dorf ◽  
J H Stimpfling

The ability of various B10 congenic resistant strains to respond to the alloantigen H-2.2 was tested. High and low antibody-producing strains were distinguished by their anti-H-2.2 hemagglutinating respones. However, these strains do not differ in their ability to respond to these antigenic differences in the mixed lymphocyte culture. The humoral response to the H-2.2 alloantigen was shown to be controlled by two interacting genes localized within the H-2 complex. Thus, F1 hybrids prepared between parental low responder strains could yield high level immune responses. In addition, strains bearing recombinant H-2 haplotypes were used to map the two distinct genes controlling the immune response. The alleles at each locus were shown to be highly polymorphic as evidenced by the asymmetric complementation patterns observed. The restricted interactions of specific alleles was termed coupled complementation. The significance of the results in the terms of mechanisms of Ir gene control are discussed.


Author(s):  
Jack Arnold ◽  
Kevin Winthrop ◽  
Paul Emery

Abstract The coronavirus disease 2019 (COVID-19) vaccination will be the largest vaccination programme in the history of the NHS. Patients on immunosuppressive therapy will be among the earliest to be vaccinated. Some evidence indicates immunosuppressive therapy inhibits humoral response to the influenza, pneumococcal and hepatitis B vaccines. The degree to which this will translate to impaired COVID-19 vaccine responses is unclear. Other evidence suggests withholding MTX for 2 weeks post-vaccination may improve responses. Rituximab has been shown to impair humoral responses for 6 months or longer post-administration. Decisions on withholding or interrupting immunosuppressive therapy around COVID-19 vaccination will need to be made prior to the availability of data on specific COVID-19 vaccine response in these patients. With this in mind, this article outlines the existing data on the effect of antirheumatic therapy on vaccine responses in patients with inflammatory arthritis and formulates a possible pragmatic management strategy for COVID-19 vaccination.


Author(s):  
Jelena Drulovic ◽  
Jovana Ivanovic ◽  
Vanja Martinovic ◽  
Olivera Tamas ◽  
Nikola Veselinovic ◽  
...  

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1244
Author(s):  
Iulia Nedelcu ◽  
Raluca Jipa ◽  
Roxana Vasilescu ◽  
Cristian Băicuș ◽  
Costin-Ioan Popescu ◽  
...  

The number of serological assays for SARS-CoV-2 has skyrocketed in the past year. Concerns have been raised regarding their performance characteristics, depending on the disease severity and the time of the analysis post-symptom onset (PSO). Thus, independent validations using an unbiased sample selection are required for meaningful serology data interpretation. We aimed to assess the clinical performance of six commercially available assays, the seroconversion, and the dynamics of the humoral response to SARS-CoV-2 infection. The study included 528 serum samples from 156 patients with follow-up visits up to six months PSO and 161 serum samples from healthy people. The IgG/total antibodies positive percentage increased and remained above 95% after six months when chemiluminescent immunoassay (CLIA) IgG antiS1/S2 and electro-chemiluminescent assay (ECLIA) total antiNP were used. At early time points PSO, chemiluminescent microparticle immunoassay (CMIA) IgM antiS achieved the best sensitivity. IgM and IgG appear simultaneously in most circumstances, and when performed in parallel the sensitivity increases. The severe and the moderate clinical forms were significantly associated with higher seropositivity percentage and antibody levels. High specificity was found in all evaluated assays, but the sensitivity was variable depending on the time PSO, severity of disease, detection method and targeted antigen.


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