IgA antibody responses to Mycobacterium tuberculosis recombinant MPT-64 and MT-10.3 (Rv3019c) antigens in pleural fluid of patients with tuberculous pleurisy.

SETTING: Microbiological tests lack sensitivity for pleural tuberculosis (TB) and histopathology is expensive, time consuming and needs specialised personnel. Immunoassay (ELISA) may be a promising approach in this respect. OBJECTIVE: To evaluate the reactivity of IgA antibody to MPT-64 and MT-10.3 recombinant mycobacterial protein antigens in pleural fluid as a marker of pleural TB, based on the fact that IgA is the main antibody in the mucosa/serosa of the gastrointestinal and respiratory tract. METHOD: Anti-MPT-64 and MT-10.3 IgA response was determined by ELISA in 72 patients with pleural TB and 27 with other pleural conditions. RESULTS: High sensitivities for IgA were measured against MPT-64 (52/72, 72%) and MT-10.3 (52/72,72%) antigens. Combining the sensitivities of both antigens, further increase in sensitivity (55/72, 76%) was obtained with no loss of specificity (96%). Similar IgA reactivity was obtained from culture-negative and culture-positive specimens. In eight pleural TB patients with human immunodeficiency virus (HIV) co-infection, the sensitivity was 88% (7/8). CONCLUSION: To our knowledge, this is the first description of the presence of IgA antibody pleural TB effusion reactive to MPT-64 and MT-10.3, with sensitivity similar to histopathological examination, which is presently considered the gold standard for pleural TB.

Evolving features of lung adenocarcinoma in Rio de Janeiro, Brazil.

Formerly considered rare, adenocarcinoma has become the commonest form of primary lung cancer in developed countries. Its clinical presentation has changed, with central tumors becoming more frequent. We reviewed all biopsies with a diagnosis of primary lung cancer obtained from October 1988 to April 1997 in a tertiary care hospital in Rio de Janeiro. Medical records from adenocarcinomas were analysed. Adenocarcinoma was the commonest form of lung cancer (168/409, 41%). Central tumors were observed in 43% according to radiological criteria and 47% according to bronchoscopic criteria. The frequency and clinical presentation of adenocarcinoma have evolved lately in Rio de Janeiro.