COMPARISON OF THE IMMUNE-RESPONSE AGAINST MYCOBACTERIUM-TUBERCULOSIS ANTIGENS BETWEEN A GROUP OF PATIENTS WITH ACTIVE PULMONARY TUBERCULOSIS AND HEALTHY HOUSEHOLD CONTACTS

The mycobacterial antigens and the factors related to protection for t he development of active tuberculosis are not known. In a natural mode l of tuberculosis, we studied 10 patients with active pulmonary tuberc ulosis (non-protective immune response) and 38 healthy household conta cts (protective immune response). We tested the lymphocyte proliferati ve response by T cell Western blotting to eight different antigen frac tions and to two purified mycobacterial antigens of 30 and 64 kD. Pati ents with active tuberculosis recognized fractions with molecular weig hts of 80-114, 60-80, 28-41 and 14-19 kD. Household contacts recognize d the same fractions except the 14-19 kD. The response to the 64-kD an tigen was not significantly different between groups. In contrast, 10% of the patients with active tuberculosis and 73% of the household con tacts responded to the 30-kD antigen. The humoral response against the 30-kD antigen by ELISA showed a significantly higher production of an tibodies in tuberculosis patients compared with household contacts. We conclude that patients with active pulmonary tuberculosis develop an immune response characterized by poor proliferative response to the 30 -kD antigen with a strong humoral response, whereas the opposite occur s in healthy subjects infected by Mycobacterium tuberculosis.