Diagnostic value of different serological tests for tuberculosis in Poland

The aim of the study was to test the diagnostic accuracy of several serological assays for the diagnosis of tuberculosis (TB) in the Polish population. ELISA based assays detecting: 38 kDa+LAM - MycoM, MycoA and MycoG, 38 kDa - Pathozyme TB complex, 38 kDa+16 kDa - Pathozyme TB complex plus were used. The humoral immune response was analyzed in a group of 319 TB patients (289 adults and 30 children) and in a control group consisting of 66 sarcoidosis cases, 16 cases of mycobacterial infections other than tuberculosis, 35 lung cancer patients, and 70 healthy volunteers. Among the TB patients, there were 267 cases of pulmonary TB and 52 cases of extrapulmonary TB. Sensitivity varied between 32% (IgM) and 63% (IgA) and increased in culture positive tuberculosis and in chronic cases. Specificity was the highest for the tests based on recombinant antibodies (98%). Sensitivity of the IgG test in extrapulmonary TB was comparable with that in pulmonary TB. Overall, sensitivity of the examined tests was lower in children than in adults, but it varied depending on the age and phase of the disease. We conclude that the ELISA-based tests may be a useful tool for improving the diagnosis of TB, especially in adults and in those countries where the prevalence of culture positive and chronic cases is high.