Enzyme-linked immunosorbent assay for the detection of antibodies against Mycobacterium tuberculosis in bronchial washings and serum.
This prospective study evaluates an enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies against Mycobacterium tuberculosis when applied to serum and bronchial washings (BW) of patients requiring bronchoscopy for definitive diagnosis. The ELISA employed an adsorbed fraction of mycobacterial sonicates as antigen. Of the 57 patients tested, 12 had tuberculosis (TB), 13 had malignant disease, 14 acute pneumonia or chronic destructive pneumonia, 13 had no demonstrable disease, and five had miscellaneous diseases. The mean optical density (OD) at 492 nm for a 1 in 40 dilution of serum of patients with TB was 0.338 +/- 0.218 and for control subjects was 0.162 +/- 0.098 (p = 0.0323). Values for neat BW were 0.317 +/- 0.122 for TB patients and 0.191 +/- 0.140 for control subjects (p = 0.0084). Using stepwise discriminant analysis, the ELISA on serum gave a sensitivity of 70.0 percent and specificity of 86.4 percent and 83.3 percent correct classification. When applied to BW, there was a 72.7 percent sensitivity, a 82.2 percent specificity, and patients were correctly classified in 80.4 percent of cases. It is concluded that the assay is a useful and reliable adjunct to conventional tests for tuberculosis.
D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D001992:Bronchoalveolar Lavage Fluid / Q000032:analysis; D001999:Bronchoscopy; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology; D011446:Prospective Studies; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
D000907:Antibodies, Bacterial