Serodiagnosis of pericardial tuberculosis

The AIDS epidemic has led to the resurgence of tuberculosis. Extrapulmonary manifestations may appear in over half of the patients who are dually infected. This has resulted in a rising incidence of tuberculous pericarditis in several parts of Africa such as Tanzania. We tested a solid-phase antibody competition sandwich ELISA (SACT-SE) as a potential means of diagnosing tuberculous pericarditis. Fifty-one African patients with clinically diagnosed tuberculous pericardial effusion (of whom 25 had confirmation by pericardial fluid culture) were tested using a monoclonal antibody (CDC/WHO ref. no. IT39) which was raised against a specific epitope on the Mycobacterium tuberculosis 30 kDa antigen. All but one patient had negative sputum microscopy for acid-fast bacilli. A sensitivity of 61% (at 96% specificity) was achieved. Sera from 25 African patients with smear-positive tuberculosis were also examined; of which 20 tested positive (sensitivity 80%). This is the largest study to date on the potential application of serology in diagnosing pericardial tuberculosis.