[Serodiagnosis in pulmonary tuberculosis. Clinical evaluation].

The IgA, IgG, IgM and IgG subsets antibodies levels were determined in 200 patients with pulmonary tuberculosis and compared to three control groups: 80 healthy individuals (50 with negative PPD skin test, 30 with positive PPD skin test), 30 leprosy patients and 20 patients with different pulmonary diseases. The technique used was an enzyme linked assay. As antigens, purified tuberculin and Ag60 from M. bovis were used. There were not statistically significant differences between antibody levels among all control groups studied, but when we compare the level in control groups with that observed in tuberculous patients, they showed higher levels of IgA, IgG, IgM, IgG2 (p less than 0.01) and IgG4 (p less than 0.05). A definite diagnosis of tuberculosis of the lung should only be established if the patient showed to be positive to IgG plus IgA or IgM and in special cases to IgG1, reaching then a diagnostic efficacy of 90% in a patient population with a 68% of positive smears for acid-fast bacilli.