[Enzyme immunoassay and immunochromatographic assay in the differential diagnosis of tuberculosis and cancer of the respiratory organs].

The informative value of immunodiagnostic assays aimed at identifying specific antibodies in the peripheral blood was studied. Indirect solid-phase enzyme immunoassay (Antitub test system, Moscow) and rapid immunochromatographic assay (TB-CHECK, France) were used. Fifty-six diagnostic patients and 18 healthy individuals were examined. The diagnosis of active tuberculosis was verified in 29 patients (Group 1) and that of lung cancer was in 27 patients (Group 2). The detection rate of and the level of antituberculosis antibodies in patients with active tuberculosis greatly differed from those in patients with lung cancer (p < 0.01). In the diagnostic patients, the sensitivity of enzyme immunoassay was 79.3%, its specificity was 88.9; the sensitivity and specificity of the rapid assay were 72.4 and 96.3%, respectively. The high specificity of the immunochromatographic assay in patients with lung cancer may reduce the number of false-positive results of the enzyme immunoassay. The concurrent use of both methods is an essential adjunct to the clinical examination of diagnostic patients, it makes it possible to reduce the time of pre-examination of cancer patients and to restrict a group of patients who need for invasive studies to specify a diagnosis.