SEROLOGICAL RESPONSE IN LEPROSY AND TUBERCULOSIS PATIENTS TO THE 18-KDA ANTIGEN OF MYCOBACTERIUM-LEPRAE AND ANTIGEN 85B OF MYCOBACTERIUM-BOVIS BCG

Two enzyme-linked immunosorbent assays (ELISAs) for the detection of l eprosy antibodies were developed. These assays were based on the recom binant 18-kDa protein of Mycobacterium leprae and the 85B antigen of M . bovis. Sera from leprosy and tuberculosis patients were analyzed, an d a phenolic glycolipid-I (PGL-I) ELISA was used as a reference test. The 18-kDa ELISA reached a sensitivity of 70% on lepromatous leprosy s era. The corresponding results for the 85B and the PGL-I ELISAs were 9 3% and 96%, respectively. The sensitivity on tuberculoid leprosy sera was 72% for the 18-kDa antigen, 95% for the 85B antigen, and 60% for t he PGL-I antigen. The 18-kDa antigen ELISA was found to have crossreac tivity to sera from patients with tuberculosis, while the 85B and PGL- I assays had high specificity.