HUMORAL RESPONSE TO MYCOBACTERIUM-TUBERCULOSIS-SPECIFIC ANTIGENS IN AFRICAN TUBERCULOSIS PATIENTS WITH HIGH PREVALENCE ON HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

Setting: The applicability of serodiagnosis of tuberculosis using Myco bacterium tuberculosis-complex-specific antigens in a Tanzanian popula tion with high prevalence of HIV. Objective: This study was performed to evaluate the usefulness, sensitivity and specificity of serology us ing M. tuberculosis-specific antigens in the diagnosis of tuberculosis in patients with and without HIV co-infection. Design: Patients with proven pulmonary and extrapulmonary tuberculosis at a major referral c entre in Tanzania were enrolled in the study. The control group consis ted of patients without a history of previous tuberculosis admitted to the trauma ward and of healthy volunteers. Sera were analysed by an e nzyme linked immunoassay (ELISA) using two M. tuberculosis specific pr oteins as antigen: the 38 kDa protein [3T] and a 17 kDa protein. In ad dition was recorded presence or absence of BCG scar and tuberculin sen sitivity and the sera were tested for HIV and analysed for beta-2-micr oglobulin content. Result: Sensitivity and specificity were markedly r educed in tuberculosis patients with HIV co-infection compared to pati ents without this disease (73% and 70% versus 52% and 50% respectively ). Conclusion: Serology for diagnosis of tuberculosis is not feasible in an HIV endemic region.