A comparative study on detection of Mycobaterium leprae derived anti-recombinant early secretory antigenic target-6 (rESAT-6) antibodies in leprosy patients, classified clinically and bacteriologically.

A homologue of Mycobacterium tuberculosis derived early secretory antigenic target-6 (ESAT-6) protein, has recently been documented to be present in Mycobacterium leprae as well. Though there is some similarity between the two homologues of ESAT-6, we have found employing M.leprae recombinant ESAT-6 (rESAT-6) that it is a potential serological reagent and seems to be promising candidate for its exploration in serological application in leprosy patients. In the present study we have observed that ESAT-6 serology correlated better with bacteriological approach than the clinical (lesion/thickened nerve count) approach for classification of leprosy patients into multibacillary (MB) and paucibacillary (PB) groups for treatment purpose.