Background: Measurement of antimycobacterial antibody may be used as an accurate diagnostic tool in childhood tuberculosis.
Materials and Methods: This study was conducted to evaluate the value of IgG, IgA, and IgM levels against A60 antigen
by using ELISA method for diagnosis of tuberculosis. 238 children aged from 6 months to 18 years old, divided into 4 groups; group A(n=51),patients with documented diagnosis of tuberculosis ;group B (n=75), patients who had close contact with TB patients; group C (n=51), patients with lung diseases other than tuberculosis; group D(n=40), healthy children
.Serums of 4 different groups of patients were studied. Results: Group A consisted of 22 smear positive, 24 smear negative, and 5 extrapulmonary tuberculosis patients. Sensitivity for bacteriologic study in smear positive cases was 51.2%. The mean levels of IgG, IgA, and IgM were
significantly high in group A compared to other groups. IgM anti-A60 antibody had 70.6% sensitivity and 62% specificity for
tuberculosis. Among the smear negative tuberculosis patients IgM anti A60 had a sensitivity of 62.1%. Sensitivity of IgM
anti-A60 in group B was 53.3% .The sensitivity of combined use of IgG and IgM was 70.6% in group A.
Conclusion: The sensitivity of serologic diagnosis of A60 antigen is higher than bacteriologic findings (77.3% vs. 51.2%).
A60-ELISA test is a simple and rapid diagnostic method, which can facilitate the diagnosis of tuberculosis. (Tanaffos 2002; 1(2): 15-19)