BACKGROUND/OBJECTIVES: An ELISA test based on mycobacterial antigen A60 for the estimation
of Anti (A60) IgG in the serum has been used successfully for the rapid diagnosis of tuberculosis
in studies done in the European countries, China and India. To demonstrate and
evaluate anti-tuberculosis anti-body IgG for rapid diagnosis of both pulmonary and extra pulmonary
tuberculosis, this study was carried out in our set up.
METHODS: ELISA assay based on mycobacterial antigen A60 (Anda Biologicals, France) was
used to the sera obtained from 69 cases of tuberculosis and 136 controls in the population of
Karachi, Sindh -Pakistan.
RESULTS: Of 136 controls, only 17.7% were positive for IgG antibodies and showing 82.3%
specificity. A very high sensitivity (88.8%) was seen in sputum positive active pulmonary tuberculosis.
Relatively low (75%) sero-positivity was seen in cases of sputum negative active pulmonary
tuberculosis compared to those of sputum positive active pulmonary tuberculosis. In
cases of extra pulmonary tuberculosis, 47.3% sensitivity was observed. In case of healed tuberculosis
quite a large number of cases was found positive for IgG (62.5%).
CONCLUSION: The estimation value of anti tuberculosis antibody IgG against A60 for the rapid
diagnosis is proved from our data. Considering all the cases of active tuberculosis and the controls
the global sensitivity of 69.8% and specificity of 82.4% were obtained when IgG antibodies
estimation were taken into account.
Tuberculosis. Sensitivity. Specificity. Diagnosis. Antibody IgG.