[Standardization of enzyme-linked immunosorbent assay ELISA to detect anti-Toxoplasma gondii IgM and IgG antibodies, and comparison with the indirect immunofluorescence technique].
Serology has been the most popular method to diagnose toxoplasmosis. Accordingly, this study standardizes an enzyme-linked immunosorbent assay (ELISA) and compares its results with the IFI technique. In the IgG detection test, the standardized technique presented a sensibility (S) of 96.77%, a specificity (SP) of 75%, with a positive predictive value (PPV) of 83.33%, a negative predictive value (NPV) of 94.74%, and an adjusted concordance (K) of 73.50%. The IFI exhibited 83.87% for S, 79.16% for SP, 83.81% for PPV, 79. 16% for NPV, and 63% for K. The rough concordance between these two tests (ELISA/IFI) was 88.35% for the IgG detection test and 81.55% for the IgM detection test. K was 70.82% and 1.31% for IgG and IgM, respectively, the correlation index (r) being 0.556 for IgG and -0. 023 for IgM. We can conclude that standardized ELISA-IgG is indicated in serologic selection processes, whereas the ELISA-IgM is not recommended for presenting low values for the adjusted concordance with the reference technique, which suggests not very reliable results.
Uchôa
C M
CM
Disciplina de Parasitologia. Departamento de Microbiologia e Parasitologia. Instituto Biomédico, Universidade Federal Fluminense/ FIOCRUZ, São Domingos, RJ, Brasil. uchoa@radnet.com.br
Duarte
R
R
Laurentino-Silva
V
V
Alexandre
G M
GM
Ferreira
H G
HG
Amendoeira
M R
MR
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards*; D019084:Fluorescent Antibody Technique, Indirect / Q000592:standards*; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014122:Toxoplasma / Q000276:immunology*
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M