Use of larval, parasitic female and egg antigens fromStrongyloides venezuelensisto detect parasite-specific IgG and immune complexes in immunodiagnosis of human strongyloidiasis

Parasitology ◽  
2012 ◽  
Vol 139 (7) ◽  
pp. 956-961 ◽  
Author(s):  
A. L. R. GONÇALVES ◽  
D. S. NUNES ◽  
M. R. F. GONÇALVES-PIRES ◽  
M. T. UETA ◽  
J. M. COSTA-CRUZ

SUMMARYThe aim of this study was to use larval, parasitic female and egg antigens fromStrongyloides venezuelensisto detect parasite-specific IgG and immune complexes in human serum samples by enzyme-linked immunosorbent assay (ELISA). In total, 95 serum samples were analysed, consisting of 30 patients harbouringS. stercoralislarvae, 30 healthy subjects and 35 patients with other parasites. Sensitivity, specificity and diagnostic efficiency were calculated. A significant statistical difference was found in the detection of immune complexes and antibodies in patients harbouringS. stercoralislarvae from larval and eggs antigens, with higher positivity using larval antigen. The larval antigen showed the highest values for sensitivity, specificity and diagnostic efficiency in ELISA from detection of immune complexes. For the first time we used IgG anti-larvae, IgG anti-parasitic females or IgG anti-eggs for immune complex detection. We concluded that the association of antibody and immune complex detection could be used in the diagnosis of human strongyloidiasis.

2015 ◽  
Vol 90 (3) ◽  
pp. 342-346 ◽  
Author(s):  
A.L.R. Gonçalves ◽  
K.C.L. de Araújo ◽  
E.F.G. Carvalho ◽  
M.T. Ueta ◽  
J.M. Costa-Cruz

AbstractIn the present study, antigens from parthenogenetic females and eggs of Strongyloides venezuelensis, or anti-parthenogenetic-female and anti-egg antigens were used to detect specific IgG and immune complex responses, respectively. Serum samples from experimentally infected immunocompetent and immunosuppressed rats were analysed on days 5, 8, 13 and 21 post-infection (dpi). An enzyme-linked immunosorbent assay (ELISA) was performed using alkaline parasite extract for specific IgG detection, and anti-parthenogenetic-female or anti-egg antigens for immune complex detection. The data were analysed using analysis of variance (ANOVA), followed by a Bonferroni test. When parthenogenetic female or egg extracts were used as antigens, specific IgGs were not detected in either immunocompetent or immunosuppressed rats. When anti-parthenogenetic-female or anti-S. venezuelensis-eggs were used, immune complexes were detected for the duration of the infection in immunosuppressed animals and were only detected between 5 and 13 dpi in immunocompetent animals. The duration of infection was not significantly different between the immunocompetent and immunosuppressed groups when anti-parthenogenetic-female or anti-S. venezuelensis-eggs were used. Parthenogenetic female extracts yielded significant differences between antibody and immune complex responses in immunocompetent rats from 5 to 13 dpi, but only on day 5 dpi in immunosuppressed rats. Exposure to S. venezuelensis egg extract yielded significant differences in both antibody and immune complex detection between immunocompetent and immunosuppressed rats for the duration of the infection. In conclusion, ELISA using alternative antigens may be a successful strategy for identifying immune complexes in serum samples and diagnosing active strongyloidiasis, particularly under conditions of immunosuppression.


2012 ◽  
Vol 130 (3) ◽  
pp. 205-208 ◽  
Author(s):  
Ana Lúcia R. Gonçalves ◽  
Claudio V. Silva ◽  
Marlene T. Ueta ◽  
Julia M. Costa-Cruz

2021 ◽  
Author(s):  
Nasamon Wanlapakorn ◽  
Nungruthai Suntronwong ◽  
Harit Phowatthanasathian ◽  
Ritthideach Yorsang ◽  
Thanunrat Thongmee ◽  
...  

Abstract Limited data are available on the responses to heterologous vaccine regimens for SARS-CoV-2, especially among countries using inactivated and adenoviral-vectored vaccines. A total of 77 participants who received heterologous prime/booster-inactivated COVID-19 vaccine and adenoviral-vectored vaccine were enrolled in our study. There were two comparison groups vaccinated with the homologous CoronaVac (N = 79) and AZD1222 (N = 80) regimen. All sera samples were tested for SARS-CoV-2 spike receptor-binding-domain (RBD) IgG using a chemiluminescent microparticle immunoassay (CMIA). The neutralizing activity in a subset of serum samples was tested against the original Wuhan strain and variants of concern, B.1.1.7 and B.1.351, using an enzyme-linked immunosorbent assay (ELISA)-based surrogate virus neutralization test (sVNT). The CoronaVac followed by the AZD1222 vaccine induced higher levels of spike RBD-specific IgG than that of two-dose CoronaVac or AZD1222 vaccines (p < 0.001). Sera samples of the CoronaVac/AZD1222 vaccine recipients elicited higher neutralizing antibody activity against the original Wuhan and the B.1.351 strain than in the recipients of the two-dose CoronaVac or AZD1222. Following the inactivated CoronaVac/adenoviral-vectored (AZD1222) vaccination administered 14–72 days apart, participants receiving the heterologous vaccine regimen had higher spike RBD-specific IgG and neutralizing activities than the homologous CoronaVac vaccine recipients.


1982 ◽  
Vol 28 (6) ◽  
pp. 1259-1271 ◽  
Author(s):  
S E Ritzmann ◽  
J C Daniels

Abstract Immune-complex-mediated injury is thought to play a role in diseases such as rheumatoid arthritis, systemic lupus erythematosus, serum sickness, various infectious diseases, and malignancies. With increased appreciation of the biological and pathological significance of circulating immune complexes has come efforts to develop appropriate techniques for identifying and measuring them. Common approaches exploit such phenomena as the attachment of complement components to antigen-antibody complexes, the presence of specialized receptors for immune complexes at the surface of cells, and the ability of rheumatoid factor to bind with immune complexes. This variety of assay systems for immune complexes has yielded abstruse results in numerous human pathological conditions. Unfortunately, these results seldom correlate with one another in a given disease. Thus, use of a panel of immune complex assays has been recommended. Indirect consequences of immune complex disease may still be appraised and evaluated with some confidence in clinical medicine: measurements of C3 and C4, cryoglobulins, serum viscosity, and turbidity of serum samples. Measurement of immune complexes may be useful in diagnosis, prognosis, and therapeutic monitoring, but it is the characterization of immune complexes that holds the greatest potential for better understanding of disease mechanisms.


2015 ◽  
Vol 22 (11) ◽  
pp. 1154-1159 ◽  
Author(s):  
D. Goldblatt ◽  
C. Y. Tan ◽  
P. Burbidge ◽  
S. McElhiney ◽  
L. McLaughlin ◽  
...  

ABSTRACTThe pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, has been in use since 1990 and was replaced in 2013 with a new reference standard, 007sp, that is projected to be available for the next 25 years. 007sp was generated under an FDA-approved clinical protocol; 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II, and a unit of blood was obtained twice from each immunized subject within 120 days following immunization. Pooled serum was prepared from the plasma of 262 subjects, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments for 89SF to the new reference standard, 007sp, to establish equivalent reference values for 13 pneumococcal capsular serotypes (1,3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) by using the WHO reference ELISA. In a second study involving three laboratories, a similar protocol was used to assign weight-based IgG concentrations in micrograms per ml to 007sp of seven serotypes (8, 10A, 11A, 12F, 15B, 22F, and 33F) also present in the 23-valent pneumococcal unconjugated polysaccharide vaccine. In addition, the IgG assignments for a 12-member WHO quality control (QC) serum panel were also extended to cover these seven serotypes. Agreement was excellent, with a concordance correlation coefficient (rc) of >0.996 when each laboratory was compared to the assigned values for the 12 WHO QC serum samples. There are four remaining pneumococcal serotypes (2, 9N, 17F, and 20) found in Pneumovax II for which IgG assignments exist for 89SF and remain to be bridged.


2008 ◽  
Vol 82 (3) ◽  
pp. 251-254 ◽  
Author(s):  
P. Mesén-Ramírez ◽  
E. Abrahams-Sandí ◽  
K. Fernández-Quesada ◽  
P. Morera

AbstractAngiostrongylus costaricensis is the aetiological agent of human abdominal angiostrongyliasis, a parasitic disease reported from the United States to Argentina, with a widespread occurrence of the nematode throughout Central and South America. This study assesses the performance of A. costaricensis eggs as antigen in an enzyme-linked immunosorbent assay (ELISA), for the determination of parasite-specific IgG1 antibodies. The specificity and the sensitivity of the method were 87% and 90.5%, respectively. Through this test it was possible to demonstrate a sharp and early decline in IgG1 antibody in serum samples taken from patients with histopathological diagnosis of abdominal angiostrongyliasis at different time points after surgical treatment. The present work demonstrated the usefulness of the egg antigen in the development of a specific diagnostic test for abdominal angiostrongylosis.


2020 ◽  
Vol 114 (8) ◽  
pp. 585-592
Author(s):  
Gabriela B da Silva ◽  
Lucas S da Faria ◽  
Camila A Lopes ◽  
Daniela S Nunes ◽  
Vanessa S Ribeiro ◽  
...  

Abstract Background Neurocysticercosis (NCC) is a neglected tropical disease and its diagnosis is still a challenge due to non-specific manifestations. Neuroimaging techniques are used in the diagnosis of NCC, however, due to the high cost of these methods and the advantages presented in the use of immunological tests, such as ease of performance and satisfactory results, immunoassays are commonly used to detect antibodies against Taenia sp. antigens. The aim of the present study was to produce, characterize and apply specific polyclonal immunoglobulin Y (IgY) anti-Taenia crassiceps extracted from egg yolk of hens immunized with T. crassiceps metacestodes. Methods Indirect enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence tests were performed for characterization of IgY antibodies. Diagnostic performance was verified by ELISA for immune complex detection testing 90 serum samples. Results Values of sensitivity, specificity, positive and negative likelihood ratios (LR+/LR−) and area under the curve (AUC) were calculated and presented the following results: sensitivity 83.3%, specificity 96.7%, AUC 0.966, LR+ 25.0 and LR− 0.17. Conclusions Results of this pioneering and innovative study demonstrate that anti-T. crassiceps IgY antibodies present potential applicability and can be used as an efficient tool in human NCC serodiagnosis.


2022 ◽  
Vol 20 (6) ◽  
pp. 72-80
Author(s):  
L. N. Lukhverchyk ◽  
G. L. Alatortseva ◽  
L. N. Nesterenko ◽  
V. Y. Kabargina ◽  
V. V. Dotsenko ◽  
...  

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.


2021 ◽  
Author(s):  
Nasamon Wanlapakorn ◽  
Nungruthai Suntronwong ◽  
Harit Phowatthanasathian ◽  
Ritthideach Yorsang ◽  
Thanunrat Thongmee ◽  
...  

Abstract Limited data are available on the responses to heterologous vaccine regimens for SARS-CoV-2, especially among countries using inactivated and adenoviral-vectored vaccines. A total of 77 participants who received heterologous prime/booster-inactivated COVID-19 vaccine (CoronaVac) and adenoviral-vectored vaccine (AZD1222) were enrolled in our study. There were two comparison groups vaccinated with the homologous CoronaVac (N = 80) and AZD1222 (N = 80) regimen. All sera samples were tested for SARS-CoV-2 spike receptor-binding-domain (RBD) IgG using a chemiluminescent microparticle immunoassay (CMIA). The neutralizing activity in a subset of serum samples was tested against the original Wuhan strain and variants of concern, B.1.1.7, B.1.617.2 and B.1.351, using an enzyme-linked immunosorbent assay (ELISA)-based surrogate virus neutralization test (sVNT). The heterologous CoronaVac/AZD1222 vaccine induced higher levels of spike RBD-specific IgG than that of two-dose homologous CoronaVac or AZD1222 vaccines (p < 0.001). Sera samples of the CoronaVac/AZD1222 vaccine recipients elicited higher neutralizing antibody activity against the original Wuhan and all variants of concern than in the recipients of the two-dose CoronaVac. Nevertheless, there were no difference in neutralizing activity against the original Wuhan and B.1.1.7 strain among heterologous CoronaVac/AZD1222 and homologous AZD1222 vaccine recipients.


1980 ◽  
Vol 26 (3) ◽  
pp. 396-402
Author(s):  
R H Kelly ◽  
M A Scholl ◽  
V S Harvey ◽  
A G Devenyi

Abstract On binding of antibody to antigen an immune complex is formed that has a net surface charge different from that of either of the two components. This, together with clonal restriction of the antibody response, gives rise to distinctive patterns that are readily apparent in stained agarose gels after routine zone electrophoresis. Most circulating immune complexes appear as a rectangular pattern, with well-defined edges, located in the gamma-region. The identity of the material responsible for these patterns has been established by three different experimental approaches: analysis of tetanus/anti-tetanus complexes formed in vitro, analysis of sera from rabbits with experimental immune complex disease, and analysis of human type II and type III cryoglobulins. Studies of reproducibility, interfering substances, and correlation with other assays for detecting immune complexes indicate that zone electrophoresis in agarose gel is a sensitive, highly specific technique for immune complex detection, of potential value as a screening tool.


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