Anti-A60 immunoglobulin G in the serodiagnosis of tuberculosis in HIV-seropositive and seronegative patients.
OBJECTIVE
A60 is a high molecular weight mycobacterial antigen complex. The detection of immunoglobulin (Ig) G antibodies to A60 has been advocated as a reasonably sensitive and specific test for active tuberculosis (TB). We aimed to compare the sensitivity of this test among HIV-seropositive and HIV-seronegative patients with pulmonary TB.


METHODS
The presence and concentration of anti-A60 IgG antibodies was assessed by enzyme-linked immunosorbent assay in 208 HIV-seropositive and 91 HIV-seronegative Zaïrian patients with smear-positive pulmonary TB. The relationship between anti-A60 IgG levels and HIV serostatus, CD4+ lymphocyte counts, presence of clinical AIDS, and tuberculin skin test results was verified.


RESULTS
Only 36.5% of the HIV-seropositive, compared with 69.2% of the HIV-seronegative patients had a positive anti-A60 IgG test (P < 0.00001). Among HIV-seropositive patients, anti-A60 IgG levels did not differ according to CD4+ lymphocyte counts, presence of clinical AIDS, or tuberculin skin test results.


CONCLUSIONS
Among patients with pulmonary TB, the sensitivity of testing for anti-A60 IgG was much lower among HIV-seropositive than among HIV-seronegative patients, even from the early stages of HIV-related immunodeficiency. This limits the utility of anti-A60 IgG-antibody testing in the diagnosis of TB among HIV-infected patients.
Pouthier
F
F
Catholic University of Louvain, Mont Godinne, Belgium.
Perriëns
J H
JH
Mukadi
Y
Y
Kayembe
T
T
St Louis
M E
ME
Brown
C
C
Prignot
J
J
D017088:AIDS-Related Opportunistic Infections / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial; D004797:Enzyme-Linked Immunosorbent Assay / Q000706:statistics & numerical data; D005260:Female; D018023:HIV Seronegativity / Q000276:immunology; D006679:HIV Seropositivity / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000706:statistics & numerical data; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G; C055539:mycobacterial A60 antigen