Estimation of rotavirus immunoglobulin G antibodies in human serum samples by enzyme-linked immunosorbent assay: expression of results as units derived from a standard curve.

ABSTRACTAnthrax, caused byBacillus anthracis, is primarily a zoonotic disease. Being a public health problem also in several developing countries, its early diagnosis is very important in human cases. In this study, we describe the use of an indirect enzyme-linked immunosorbent assay (ELISA) for detection of anti-lethal factor (anti-LF) IgG in human serum samples. A panel of 203 human serum samples consisting of 50 samples from patients with confirmed cutaneous anthrax, 93 samples from healthy controls from areas of India where anthrax is nonendemic, 44 samples from controls from an area of India where anthrax is endemic, and 16 patients with a disease confirmed not to be anthrax were evaluated with an anti-LF ELISA. The combined mean anti-LF ELISA titer for the three control groups was 0.136 ELISA unit (EU), with a 95% confidence interval (CI) of 0.120 to 0.151 EU. The observed sensitivity and specificity of the ELISA were 100% (95% CI, 92.89 to 100%) and 97.39% (95% CI, 93.44 to 99.28%), respectively, at a cutoff value of 0.375 EU, as decided by receiver operating characteristic (ROC) curve analysis. The likelihood ratio was found to be 49.98. The positive predictive value (PPV), negative predictive value (NPV), efficiency, and Youden's index (J) for reliability of the assay were 92.5%, 100%, 98.02%, and 0.97, respectively. The false-positive predictive rate and false-negative predictive rate of the assay were 2.61% and 0%. The assay could be a very useful tool for early diagnosis of cutaneous anthrax cases, as antibodies against LF appear much earlier than those against other anthrax toxins in human serum samples.

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Seroprevalence of Jamestown Canyon virus in the Japanese general population

BMC Infectious Diseases ◽

10.1186/s12879-020-05517-2 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Hirofumi Kato ◽

Masaaki Satoh ◽

Madoka Kawahara ◽

Satoshi Kitaura ◽

Tomoki Yoshikawa ◽

...

Keyword(s):

General Population ◽

Human Serum ◽

Health Agency ◽

Febrile Illness ◽

Central Nervous System Disease ◽

Enzyme Linked Immunosorbent Assay ◽

Antibody Assay ◽

Serum Samples ◽

Human Serum Samples ◽

Jamestown Canyon Virus

Abstract Background Jamestown Canyon virus (JCV) is a mosquito-borne orthobunyavirus that causes acute febrile illness, meningitis, and meningoencephalitis, mainly among adults. JCV is widely distributed in North America and the number of JCV cases in the U.S. has increased in recent years. Therefore, the central nervous system disease caused by JCV can be considered a potentially re-emerging viral disease. However, the seroprevalence of JCV is unknown in Japan. The purpose of this study is to evaluate the seroprevalence of JCV in the Japanese population. Methods We used an IgG enzyme-linked immunosorbent assay (IgG-ELISA) with JCV-infected cell-lysates and/or a neutralizing (NT) antibody assay. The cut-off value of IgG-ELISA was determined using IgG-ELISA to analyze serum specimens from 37 healthy Japanese donors. IgG-ELISA was validated by assessing its sensitivity and specificity, using 38 human serum samples previously tested for the presence or absence of antibodies against JCV and snowshoe hare virus (SSHV), in an in-house NT antibody assay conducted by the Public Health Agency of Canada. The seroepidemiological study was performed using IgG-ELISA and NT antibody assay to analyze 246 human serum samples from the serum bank of the National Institute of Infectious Diseases (NIID) in Japan. Results The cut-off value of IgG-ELISA was determined at 0.20, based on the mean (− 0.075) and standard deviation (0.092) values using Japanese donors’ sera. The sensitivity and the specificity of IgG-ELISA determined using 25 JCV-positive and 4 JCV-negative serum samples were 96 and 100%, respectively. Analysis of the 246 Japanese serum samples revealed that no specimen showed a higher value than the cut-off value of IgG-ELISA, and no sample tested positive by the NT antibody assay. Conclusions Our results showed that JCV is not circulating significantly in Japan. To the best of our knowledge, this is the first report to demonstrate the seroprevalence of JCV in the general population in Japan.

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Immunoglobulin G, A and M Light Chain Ratio in Children

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456329202900303 ◽

1992 ◽

Vol 29 (3) ◽

pp. 271-274 ◽

Cited By ~ 12

Author(s):

Á Haraldsson ◽

C M R Weemaes ◽

M J H Kock-Jansen ◽

P B J M v Eck-Arts ◽

T de Boo ◽

...

Keyword(s):

Immunosorbent Assay ◽

Light Chain ◽

Immunoglobulin G ◽

Age Groups ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Λ Light Chain

Values for the κ/λ light chain ratio in immunoglobulins G, A and M and the total κ/λ ratio, measured by enzyme linked immunosorbent assay, were evaluated in serum samples from different age groups (114 children, aged from 1 month to 15 years, and 20 adults). The IgG κ/λ ratio decreased in the first 6 months and subsequently increased slowly during childhood towards the adult value of 2·0. The IgM κ/λ ratio increased at a greater rate than IgG κ/λ ratio in the first years of life and thereafter rose slightly throughout childhood to reach an adult value of 1·7. A decreasing IgA κ/λ ratio was found from 1 month of age onwards to an adult value of 1·1. The pattern of total κ/λ ratio was similar to the IgG κ/λ ratio with an adult value of 2·0.

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Development of the ELISA Test System for Quantitative Determination of IgG to the Varizella zoster virus in Human Serum and Assessment of its Diagnostic Efficiency

Epidemiology and Vaccinal Prevention ◽

10.31631/2073-3046-2021-20-6-72-80 ◽

2022 ◽

Vol 20 (6) ◽

pp. 72-80

Author(s):

L. N. Lukhverchyk ◽

G. L. Alatortseva ◽

L. N. Nesterenko ◽

V. Y. Kabargina ◽

V. V. Dotsenko ◽

...

Keyword(s):

Herpes Zoster ◽

Blood Serum ◽

Human Serum ◽

Immunosorbent Assay ◽

Test System ◽

Enzyme Linked Immunosorbent Assay ◽

Diagnostic Efficiency ◽

Functional Characteristics ◽

Serum Samples ◽

Population Immunity

Relevance. The introduction of Varicella vaccine prophylaxis explains the need to develop a methodology for monitoring the vaccination effectiveness and the intensity of population immunity. This problem can be solved using quantitative immunoassay methods. Aim. Development of an enzyme-linked immunosorbent assay for the concentration of class G immunoglobulins (AB) to Varicella zoster virus (VZV) determining and assessing its functional characteristics and diagnostic efficiency. Materials and methods. Recombinant antigen GE VZV. WHO International Standard for Antibodies to VZV W1044. Blood serum samples from healthy people and patients with Chickenpox and Herpes zoster, blood serum samples containing IgG antibodies to herpes simplex viruses of the first and second types, cytomegalovirus, Epstein-Barr virus. Anti-VZV ELISA (IgG) reagent kit (Euroimmun, Germany). Indirect enzyme-linked immunosorbent assay. Immunization of animals with recombinant antigen GE, isolation, and purification of specific antibodies. Conjugation of monoclonal antibodies to human IgG with antibodies to antigen GE and with horseradish peroxidase. Results. An enzyme-linked immunosorbent assay in «an indirect» format has been developed to determine the specific antibodies to VZV concentration (IU/ml) in human serum/plasma. An artificial calibrator for determining the concentration of AB-VZV had been synthesized and standardized according to the International WHO-standard W1044. The main functional characteristics of the developed enzyme-linked immunosorbent assay are determined in accordance with GOST 51352-2013. The diagnostic kit was tested on blood serum samples from children with chickenpox (n = 43), adults with Herpes zoster (n = 158), healthy individuals (n = 781). The diagnostic sensitivity of the test system was 85%, the diagnostic specificity was 87% according to the ROC analysis. The absence of cross-reactivity of the test system was shown on samples with serological markers of other herpesvirus infections (n = 94). Comparative trials of the developed test system and its commercial analog, the Anti-VZV ELISA (IgG) reagent kit, did not reveal statistically significant differences between their functional characteristics. Conclusions. The developed test system for determining of the AB-VZV concentration in human serum/plasma in terms of its functional characteristics meets the GOST requirements, is characterized by high diagnostic efficiency, can be used to monitor the effectiveness of vaccine prophylaxis and strength of population immunity, as well as to assess the immune response in chickenpox and Herpes zoster.

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Analysis of UK Sera for Aflatoxin by Enzyme-linked Immunosorbent Assay

Human Toxicology ◽

10.1177/096032718800700410 ◽

1988 ◽

Vol 7 (4) ◽

pp. 353-356 ◽

Cited By ~ 18

Author(s):

A.P. Wilkinson ◽

D.W. Denning ◽

M.R.A. Morgan

Keyword(s):

Human Serum ◽

Direct Measurement ◽

Immunosorbent Assay ◽

Human Exposure ◽

Blood Donors ◽

Enzyme Linked Immunosorbent Assay ◽

Fungal Metabolites ◽

Serum Samples ◽

Imported Food ◽

The Uk

1 Aflatoxins are toxic, carcinogenic secondary fungal metabolites produced by certain moulds that commonly infest foods. Measurement of aflatoxins in human serum would give a direct measurement of exposure. 2 Twenty-seven serum samples from UK blood donors were found to contain aflatoxin levels not greater than 64 pmol/1 (20 pg/ml) by an enzyme-linked immunosorbent assay. 3 These findings may indicate that present UK guideline tolerances for aflatoxin in imported food are effective in limiting human exposure to toxic aflatoxins in the UK diet, though further work would be needed to confirm this. In particular, sub-populations suspected of being at higher risk may need special considerations.

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