45/47 kilodalton (APA) antigen capture and antibody detection assays for the diagnosis of tuberculosis.
METHODS
APA complex (45/47 kDa) is an antigen specifically excreted by Mycobacterium tuberculosis and could therefore be a good candidate for diagnosis.


OBJECTIVE
To develop three APA immunocapture ELISA assays using monoclonal antibodies (Mabs) and one IgG anti-APA ELISA test, and to determine their usefulness for the diagnosis of tuberculosis in Madagascar.


METHODS
For the Ag assays, 23 negative sputum and serum samples and 64 pairs of sputum and serum from active smear-positive patients (PTM+) were tested. For antibody assay, 116 negative controls, 143 PTM+ and 54 extra-pulmonary tuberculosis patients were tested.


RESULTS
The sensitivities of the APA antigen detection assays were low (less than 40%) for a specificity of 95.6%, using either monoclonal antibodies or clinical specimens. The anti-APA serology was more sensitive (76.9% for PTM+ patients) but less specific (73.2%). Due to their poor predictive values, these tests cannot be recommended for the routine diagnosis of tuberculosis in Madagascar.
Chanteau
S
S
Institut Pasteur de Madagascar, Antananarivo. chanteau@pasteur.mg
Rasolofo
V
V
Rasolonavalona
T
T
Ramarokoto
H
H
Horn
C
C
Aurégan
G
G
Marchal
G
G
D000907:Antibodies, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008270:Madagascar; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014376:Tuberculosis / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology* / Q000382:microbiology
C095715:45-47 kDa antigen complex, Mycobacterium; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D006023:Glycoproteins; D007074:Immunoglobulin G