Serologic response to a secreted and a cytosolic antigen of Mycobacterium tuberculosis in childhood tuberculosis.
OBJECTIVE
Bacteriologic diagnosis of childhood tuberculosis is difficult, and alternate methods are needed. The utility of a serologic test for major secretory antigen (30 kDa) and a cytosolic antigen (16 kDa) of Mycobacterium tuberculosis was evaluated for the diagnosis of tuberculosis in children.


METHODS
Enzyme-linked immunosorbent assay was used. Specific IgG, IgA and IgM antibodies were measured in the sera from 26 clinically and/or bacteriologically diagnosed cases of childhood tuberculosis and 61 normal children.


RESULTS
Anti-IgG antibodies alone, against both 30- and 16-kDa antigens, were detected in 65.4% of patients. However, by combination of all three isotypes, increased sensitivities of 84.6 and 73%, with a specificity of 96.7% each, were obtained for 30- and 16-kDa antigens, respectively.


CONCLUSIONS
We found good specificity and reasonably good sensitivity for detection of antibodies by enzyme-linked immunosorbent assay to 30-kDa antigen alone. The 16-kDa antigen did not perform as well.
Raja
A
A
Department of Immunology, Tuberculosis Research Centre, Chennai, India.
Ranganathan
U D
UD
Bethunaickan
R
R
Dharmalingam
V
V
D000217:Acyltransferases; D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003600:Cytosol / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D000217:Acyltransferases; C121433:antigen 85B, Mycobacterium tuberculosis