scholarly journals Serological Evaluation of Specific-Antibody Levels in Patients Treated for Chronic Chagas' Disease

2007 ◽  
Vol 15 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Olga Sánchez Negrette ◽  
Fernando J. Sánchez Valdéz ◽  
Carlos D. Lacunza ◽  
María Fernanda García Bustos ◽  
María Celia Mora ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Treatment Effectiveness ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Recombinant Antigens ◽  
Antibody Titers ◽  
Laboratory Procedures ◽  
The Individual ◽  
Antibody Levels

ABSTRACT Serological tests are the main laboratory procedures used for diagnosis during the indeterminate and chronic stages of Chagas' disease. A serological regression to negativity is the main criterion used to define parasitological cure in treated patients. The aim of this work was to monitor the individual specificities of antibody levels for 3 years posttreatment in 18 adult patients. Conventional serological techniques (hemagglutination assays and enzyme-linked immunosorbent assay [ELISA]) were modified by using recombinant antigens to detect early markers of treatment effectiveness. For this purpose, serum samples were taken before and during treatment and every 6 months after treatment for at least 3 years. When hemagglutination assays were used, a decrease in antibody levels was observed in only one patient. When ELISA with serum dilutions was used, antibody clearance became much more apparent: in 77.7% (14/18) of the patients, antibody titers became negative with time. This was observed at serum dilutions of 1/320 and occurred between the 6th and the 30th months posttreatment. The immune response and the interval for a serological regression to negativity were different for each patient. For some of the recombinant antigens, only 50% (9/18) of the patients reached the serological regression to negativity. Recombinant antigen 13 might be a good marker of treatment effectiveness, since 66.6% (six of nine) of the patients presented with an early regression to negativity for specific antibodies to this antigen (P = 0.002).

scholarly journals Evaluation of Recombinant Antigens for Serodiagnosis of Chagas’ Disease in South and Central America

1999 ◽  
Vol 37 (5) ◽  
pp. 1554-1560 ◽  
Author(s):  
Eufrosina S. Umezawa ◽  
Sueli F. Bastos ◽  
Mario E. Camargo ◽  
Luci M. Yamauchi ◽  
Márcia R. Santos ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Recombinant Proteins ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Recombinant Antigen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Recombinant Antigens ◽  
Fusion Products

The commercially available diagnostic tests for Chagas’ disease employ whole extracts or semipurified fractions ofTrypanosoma cruzi epimastigotes. Considerable variation in the reproducibility and reliability of these tests has been reported by different research laboratories, mainly due to cross-reactivity with other pathogens and standardization of the reagents. The use of recombinant antigens for the serodiagnosis of Chagas’ disease is recommended to increase the sensitivity and specificity of serological tests. Expressed in Escherichia coli, as fusion products with glutathione S-transferase, six T. cruzirecombinant antigens (H49, JL7, A13, B13, JL8, and 1F8) were evaluated in an enzyme-linked immunosorbent assay for Chagas’ disease. The study was carried out with a panel of 541 serum samples of chagasic and nonchagasic patients from nine countries of Latin America (Argentina, Bolivia, Brazil, Chile, Colombia, El Salvador, Guatemala, Honduras, and Venezuela). The optimal concentration of each recombinant antigen for coating of plates was determined with the help of125I-labelled recombinant proteins. While the specificity of the epimastigote antigen was 84% because of false positives from leishmaniasis cases, for the recombinant antigens it varied from 96.2 to 99.6%. Recombinant antigens reacted with 79 to 100% of serum samples from chronic chagasic patients. In this way, it is proposed that a mixture of a few T. cruzi recombinant antigens should be employed in a diagnostic kit to minimize individual variation and promote high sensitivity in the diagnosis of Chagas’ disease.

scholarly journals Diagnostic Performance of Commercially Available Enzyme-Linked Immunosorbent Assay Kit in the Diagnosis of Extrapulmonary Tuberculosis

2013 ◽  
Vol 5 (01) ◽  
pp. 11-16 ◽  
Author(s):  
Manimuthu Mani Sankar ◽  
Veena Balooni ◽  
Jitendra Singh ◽  
Sarman Singh
Keyword(s):  
Developing Countries ◽  
Diagnostic Performance ◽  
Extrapulmonary Tuberculosis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Pulmonary Tb ◽  
The Mean ◽  
The Individual ◽  
Individual Specificity

ABSTRACT Objectives: Antibody based serodiagnosis tests for tuberculosis (TB) was used widely in developed and developing countries. Pathozyme Myco® immunoglobulin (Ig) M, IgA, and IgG were evaluated in pulmonary TB in many studies. Materials and Methods: In this study we assessed this commercially available kit in detecting extrapulmonary TB (EPTB). Results: A total of 354 subjects were recruited for the study, of which 217 (61.2%) were EPTB patients and 137 (38.7%) were subjects with no suggestive TB. The mean age was 29.7 ± 13.7 and 31.2 ± 15.2 years, respectively for two groups. Serum samples were tested for IgM, IgA, and IgG using Pathozyme Myco® IgM, IgA, and IgG kit. The individual specificity rates of IgM, IgA, and IgG were 70.8% (95% confidence interval (CI): 62.7-77.7), 77.3% (95% CI: 68.6-83.5), and 68.6%. (95% CI: 60.4-75.7); while their sensitivity was 29% (95% CI: 23.4-35.4), 24.4% (95% CI: 19.1-30.5), and 34.5% (95% CI: 28.5-41.1); respectively. Conclusion: The serological tests either singly or in combination failed or performed poorly to diagnose EPTB.

scholarly journals ELISA Based Anthrax Antibody Titer in Cattle Induced by Locally Prepared Anthrax Vaccine Originated from Sterne F-24 Strain in Bangladesh

2016 ◽  
Vol 4 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Jayedul Hassan ◽  
Md Bahanur Rahman ◽  
Shah Md Ziqrul Haq Chowdhury ◽  
Shushanto Kumar Rabidas ◽  
Md Shafiullah Parvej ◽  
...  
Keyword(s):  
Reference Value ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Post Vaccination ◽  
Blood Samples ◽  
Anthrax Vaccine ◽  
Antibody Titers ◽  
Antibody Levels ◽  
And Control ◽  
Adequate Antibody Response

Vaccination is usually practiced to prevent and control anthrax in Bangladesh. For this purpose, vaccine prepared from Sterne F-24 strain ofBacillus anthracisby Livestock Research Institute (LRI), Mohakhali, Dhakahas long been used in this country. However, in some cases anthrax occurred in vaccinated animals in Bangladesh. A total of 100 cattle at LalTeer Livestock Research and Development Farm, LalTeerLivestock Limited, Bangladesh, aging between 3-6 years and weighing between 250-400 kg were randomly selected for vaccination purpose. Blood samples (n=100) were collected before the vaccination for collecting pre-vaccination serum, andthe animals were vaccinated (at 1 mL/animal; 1x107 spores/mL) with the anthrax vaccine produced by LRI. All blood samples from the vaccinated animals were collected on day 7, 28, 60, 90, 120, 150, 180, 240, 270, 300, 330, and 360 of post-vaccination, and serum samples were prepared. The antibody levels in the serum samples against anthrax were monitored using an Enzyme-Linked Immunosorbent Assay (ELISA). Over the course of 12 months, the antibody titers were found at the level higher than the reference value. Though there were reports on anthrax suspected cases in this farm, no such cases were reported during the study period. Thus, the vaccine appears to induce adequate antibody response against anthrax in Bangladesh.Microbes and Health, January 2015. 4(1): 36-38

scholarly journals Longitudinal analysis of SARS-CoV-2 seroprevalence using multiple serology platforms

2021 ◽  
Author(s):  
Juan Manuel Carreño ◽  
Damodara Rao Mendu ◽  
Viviana Simon ◽  
Masood A Shariff ◽  
Gagandeep Singh ◽  
...  
Keyword(s):  
Longitudinal Analysis ◽  
Early Stage ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Care Workers ◽  
Previous Infection ◽  
Research Grade ◽  
Antibody Levels ◽  
Abbott Architect

AbstractSerological tests are important tools helping to determine previous infection with severe acute respiratory disease coronavirus 2 (SARS-CoV-2) and to monitor immune responses. The current tests are based on spike (S), the receptor binding domain (RBD), or the nucleoprotein (NP) as substrate. Here, we used samples from a high seroprevalence cohort of health care workers (HCWs) to perform a longitudinal analysis of the antibody responses using three distinct serological assays. 501 serum samples were tested using: a) a research-grade RBD and spike based tandem enzyme-linked immunosorbent assay (MS–RBD ELISA, MS-spike ELISA), b) a commercial RBD and spike based tandem ELISA (Kantaro-RBD, -spike), and c) a commercial NP-based chemiluminescent microparticle immunoassay (CMIA, Abbott Architect). Seroprevalence ranged around 28% during the early stage of the pandemic (a: 28.4% positives; b: 28.1%; c: 27.3%). Good correlation was observed between the MS and Kantaro RBD ELISAs and between the MS and Kantaro spike ELISAs. By contrast, modest correlations were observed between the Abbott Architect and both RBD and spike-based assays. A proportion of HCWs (n=178) were sampled again 3-5 months after the first time point. Although antibody levels declined in most of the positive individuals, the overall seroprevalence measured by RBD-spike based assays remained unchanged. However the seroprevalence of NP-reactive antibodies significantly declined. Lastly, we tested six samples of individuals who received two doses of SARS-CoV-2 mRNA vaccine and found that seroconversion was detected by the RBD-spike assays but – of course as expected - not the NP based assay. In summary, our results consolidate the strength of different serological assays to assess the magnitude and duration of antibodies to SARS-CoV-2.

Comparison of an enzyme-linked immunosorbent assay for quantitation of rotavirus antibodies with complement fixation in an epidemiological survey

1978 ◽  
Vol 8 (3) ◽  
pp. 268-276
Author(s):  
L H Ghose ◽  
R D Schnagl ◽  
I H Holmes
Keyword(s):  
Immunosorbent Assay ◽  
Complement Fixation ◽  
Age Groups ◽  
Enzyme Reaction ◽  
Epidemiological Survey ◽  
Enzyme Linked Immunosorbent Assay ◽  
Marker Enzyme ◽  
Aminosalicylic Acid ◽  
Antibody Titers ◽  
Antibody Levels

The development of a micro-scale enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase as the marker enzyme for the detection and measurement of human rotavirus antibodies is described. A semipurified preparation of the serologically related simian agent, SA-11 virus, was used as the antigen. Test sera were reacted with antigen-sensitized wells in disposable poly-vinyl microplates. Any attached antibody was detected by the addition of peroxidase-labeled anti-species immunoglobulin (conjugate) followed by assay of the enzyme reaction with its substrate, hydrogen peroxide plus 5-aminosalicylic acid. This micro-ELISA was compared with complement fixation in a seroepidemiological study of the age prevalence of rotavirus antibody in Aboriginal and European populations living in the same outback area in Australia. The ELISA (results read with the naked eye) proved to be approximately 16 times more sensitive than complement fixation. Of Aborigines, 71% had rotavirus complement-fixing antibody, as compared to 45% of Europeans. By ELISA 100% of both populations had rotavirus antibodies. Mean antibody titers in the different age groups were higher in Aborigines than in Europeans. Antibody levels rose steeply throughout the first 20 years of life, remained high during the next 20 years, then increased again at least up to the age of 60 years. The micro-ELISA was practical, simple to perform, and more suitable than complement fixation for large seroepidemiological rotavirus studies. It also has potential for serodiagnosis of the disease, both in the laboratory and in the field.

Study of Antibody Levels in Children with Purulent Otitis Media

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 117-120 ◽  
Author(s):  
P. Branefors ◽  
T. Dahlberg ◽  
O. Nylén
Keyword(s):  
Otitis Media ◽  
Serum Antibody ◽  
Acute Otitis Media ◽  
High Serum ◽  
Haemophilus Influenzae Type ◽  
Enzyme Linked Immunosorbent Assay ◽  
Polysaccharide Antigens ◽  
Antibody Titers ◽  
Iga Antibody ◽  
Antibody Levels

A series of episodes of acute otitis media were studied with reference to the bacterial findings in the nasopharynx and the specific antibody response in a group of children nine months to ten years of age, with previous frequent episodes of acute otitis media, Serum IgG, IgM and IgA antibody levels against five polysaccharide antigens, namely Haemophilus influenzae type b and Streptococcus pneumoniae types 3, 6, 19 and 23, were studied by means of an enzyme-linked immunosorbent assay. The selection of polysaccharide antigens was based on isolation frequency. The sera to be tested were tenfold serially diluted. An extinction of 0.2 over the base was taken as the end-point titer and expressed as in-log10. The results showed that most children including those under three years of age showed increasing homologous antibody titers at an infection, or had already initially very high antibody titers, especially of the IgG class. The titers reached levels of 104 to 105. In some cases, however, it could be shown that high serum antibody titers did not give protection against a new infection with the same serological type of bacteria. It was also demonstrated that most children, regardless of age, had IgG and IgM titers against the heterologous antigens. In some cases the levels were quite high (103 to 104). However, the IgA antibody levels were lower and in a considerable number of samples antibodies were not even detectable.

scholarly journals Serodiagnosis of Louse-Borne Relapsing Fever with Glycerophosphodiester Phosphodiesterase (GlpQ) fromBorrelia recurrentis

2000 ◽  
Vol 38 (10) ◽  
pp. 3561-3571 ◽  
Author(s):  
Stephen F. Porcella ◽  
Sandra J. Raffel ◽  
Merry E. Schrumpf ◽  
Martin E. Schriefer ◽  
David T. Dennis ◽  
...  
Keyword(s):  
Serological Test ◽  
Geometric Mean ◽  
Eastern Africa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Relapsing Fever ◽  
Serum Samples ◽  
Serological Tests ◽  
Whole Cell ◽  
Convalescent Phase ◽  
Glycerophosphodiester Phosphodiesterase

Human louse-borne relapsing fever occurs in sporadic outbreaks in central and eastern Africa that are characterized by significant morbidity and mortality. Isolates of the causative agent,Borrelia recurrentis, were obtained from the blood of four patients during a recent epidemic of the disease in southern Sudan. TheglpQ gene, encoding glycerophosphodiester phosphodiesterase, from these isolates was sequenced and compared with the glpQ sequences obtained from other relapsing-fever spirochetes. Previously we showed that GlpQ of Borrelia hermsii is an immunogenic protein with utility as a serological test antigen for discriminating tick-borne relapsing fever from Lyme disease. In the present work, we cloned and expressed theglpQ gene from B. recurrentis and used recombinant GlpQ in serological tests. Acute- and convalescent-phase serum samples obtained from 42 patients with louse-borne relapsing fever were tested with an indirect immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA) that used whole cells ofB. recurrentis and with immunoblotting to whole-cell lysates of the spirochete and Escherichia coli producing recombinant GlpQ. The geometric mean titers of the acute- and convalescent-phase serum samples measured by IFA were 1:83 and 1:575, respectively. The immunoblot analysis identified a high level of reactivity and seroconversion to GlpQ, and the assay was more sensitive than the whole-cell IFA and ELISA using purified, recombinant histidine-tagged GlpQ. Serum antibodies to GlpQ and other antigens persisted for 27 years in one patient. We conclude that assessment of anti-GlpQ antibodies will allow serological confirmation of louse-borne relapsing fever and determination of disease prevalence.

Toxoplasmosis: Maternal and Pediatric Findings in 23,000 Pregnancies

PEDIATRICS ◽  
1988 ◽  
Vol 82 (2) ◽  
pp. 181-192
Author(s):  
John L. Sever ◽  
Jonas H. Ellenberg ◽  
Anita C. Ley ◽  
David L. Madden ◽  
David A. Fuccillo ◽  
...  
Keyword(s):  
Fluorescent Antibody ◽  
Congenital Toxoplasmosis ◽  
High Risk Group ◽  
Enzyme Linked Immunosorbent Assay ◽  
Laboratory Findings ◽  
Indirect Hemagglutination ◽  
Mother And Child ◽  
Antibody Titers ◽  
Low Iq ◽  
Antibody Levels

An analysis of the antibody titers to toxoplasmosis for 22,845 pregnant women in the Collaborative Perinatal Project was conducted in relation to clinical and laboratory findings in the mothers and children through 7 years of age. More than 900 observations were considered for each mother and child. The major findings were in the children and included a predicted doubling in the frequency of deafness among children born to women with antibody to toxoplasmosis, a predicted 60% increase in microcephaly, and a 30% increase in low IQ (<70) in association with the presence of high maternal antibody titer (256 to 512) to toxoplasma. A serologically defined high-risk group of mothers was identified on the basis of high indirect hemagglutination antibody levels or seroconversions and increased IgM toxoplasma antibody levels (indirect fluorescent antibody ≥32, enzyme-linked immunosorbent assay ≥0.7). Of the 15 pregnancies in this group, two children had congenital toxoplasmosis and three were stillborn.

scholarly journals Expression of the Campylobacter jejuni FliD protein and its reaction to chicken sera

2020 ◽  
Vol 367 (14) ◽  
Author(s):  
Xiao-Yan Zhang ◽  
Qian Zhou ◽  
Meng-Jun Tang ◽  
Jun-Hua Pu ◽  
Yan-Feng Fan ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Broiler Chickens ◽  
Human Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Capping Protein ◽  
Cultural Status ◽  
Bacterial Gastroenteritis ◽  
Antibody Levels ◽  
Culture Negative

ABSTRACT Campylobacter is a leading causative pathogen of acute bacterial gastroenteritis among humans. Contaminated chicken products are regarded as major sources of human infection. The flagellar capping protein (FliD), which plays important roles in colonization and adhesion to the mucosal surface of chicken ceca, is conserved among Campylobacter jejuni strains. In this study, the recombinant C. jejuni FliD protein was expressed, purified and used as a coated protein to examine the prevalence of C. jejuni antibodies in chickens. The anti-FliD antibody was prevalent among chicken serum samples taken from different farms in the diverse regions of Jiangsu province by using enzyme-linked immunosorbent assay. The Campylobacter antibody was present in culture-negative chickens. No strong dose–response relationships were observed between serum FliD antibody levels and Campylobacter cultural status. These results provide a basis for further evaluating FliD as a vaccine candidate for broiler chickens or for examining host–C. jejuni interactions, with implications for improving food safety.

scholarly journals IgM and IgA Antibody Responses in 12 Cases of Human Acquired Toxoplasmosis

1997 ◽  
Vol 39 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Emília E. H. TAKAHASHI ◽  
Cláudio L. ROSSI
Keyword(s):  
Serological Test ◽  
Clinical Manifestations ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Iga Antibodies ◽  
Direct Elisa ◽  
Acute Toxoplasmosis ◽  
Antibody Levels ◽  
Acquired Toxoplasmosis

The persistence, in some subjects, of specific IgM antibodies to Toxoplasma gondii for several months after the acute phase of infection has complicated the interpretation of serological test results for toxoplasmosis. Several reports have emphasized the value of the detection of Toxoplasma-specific IgA antibodies for the diagnosis of acute toxoplasmosis. In this article, we report the follow-up profiles of Toxoplasma-specific IgM and IgA antibodies in serum samples obtained from 12 patients at various intervals after the onset of the clinical manifestations of infection. IgM antibodies were detected by the indirect immunofluorescence (IIF) test, antibody capture enzyme-linked immunosorbent assay (cELISA) and enzyme-mediated chemilluminescent technique (CmL). IgA antibodies were quantified by the direct ELISA (dELISA) and cELISA procedures. As defined by the manufacturer of the cELISA test for IgA used, most patients with acute toxoplasmosis have antibody levels > 40 arbritary units per ml (AU/ml). At values > 40 AU/ml, the cELISA for IgA detected significant antibody levels for a shorter time than the other techniques used for IgM and IgA detection. However, IgA levels <FONT FACE="Symbol">£</font> 40 AU/ml do not exclude the possibility of acute toxoplasmosis since such levels can be reached very soon after infection with T. gondii. The results obtained in the present study show that the serological diagnosis of acute toxoplasmosis may not be such an easy task. Our data suggest that use of the IgA-cELISA concomitantly with IgM antibody screening could permit, in some circumstances, a more efficient diagnosis of acute acquired toxoplasmosis

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