Humoral response to M. tuberculosis antigens in patients with tuberculosis in the Gambia

Abstract

New tests to diagnose active tuberculosis (TB) that are simple, rapid and inexpensive, yet sensitive and specific are urgently needed. We assessed the sensitivity and specificity of seven different M. tuberculosis antigens for the diagnosis of active pulmonary TB in The Gambia. Three of the antigens tested were restricted, i.e. absent from BCG and some non-tuberculous mycobacteria (ESAT6, CFP-10 and Rv3871), and four shared, i.e. common to most mycobacteria (38kDa, GLU-S, 19kDa and 14kDa). Sera from 100 patients with active pulmonary TB, 100 household contacts, and 100 healthy neighborhood controls, in the Gambia, were tested by ELISA for antibodies to these 7 antigens. The sensitivity and specificity of both the shared and the restricted antigens were unacceptably low. In countries with high, rates of TB, such as the Gambia, the clinical utility of serologic testing to diagnose active tuberculosis remains limited