[Serum reactivity of antigen fractions of atypical mycobacteria in patients with lung diseases].

In connection with studies on the pathogenesis of sarcoidosis antigen fractions were isolated from 8 mycobacteria species, three out of each strain. These fractions were tested for their reactivity to serum antibodies by means of RIA-technique, using 40 selected sera from controls, and patients with sarcoidosis, tuberculosis and asthma. Comparing the results (average titer steps) sera from asthmatics showed the lowest and those from sarcoidosis patients the highest reactivities to the mycobacterial antigen fractions. The reactivities clearly differed in dependence on the mycobacteria species. The highest mean reactivity in sarcoidosis patients was found with the HIP-antigen fraction of M. xenopi. It was 8 times higher compared to the control sera as well as the tuberculosis sera and 32 times higher than that of the asthma sera. There were also clear differences in the reactivities within the sarcoidosis sera tested. In sera from patients with clinically inactive sarcoidosis there were found nearly the same or only slightly higher titer steps than in control sera as well as tuberculosis sera, however in clinically active sarcoidosis the titer steps were clearly elevated. The findings are seen in connection with the role of atypical mycobacteria (MOTT) in the pathogenesis of sarcoidosis. The potential applications of the HIP- and Triton X-100 antigen fractions for in vitro diagnostics are discussed.