T-LYMPHOCYTE REACTIVITY OF LEPROSY PATIENTS AND HEALTHY CONTACTS FROMA LEPROSY-ENDEMIC POPULATION TO DELIPIDIFIED CELL COMPONENTS OF MYCOBACTERIUM-LEPRAE

In this study, we measured in vitro proliferative responses of periphe ral blood mononuclear cells from both leprosy patients across the clin ical spectrum and also healthy contacts from a leprosy-endemic populat ion to delipidified cell components of Mycobacterium leprae (DCC) and Dharmendra lepromin. Dharmendra lepromin was poor in inducing in vitro T cell proliferation in all the study groups, even though it elicited marked in vivo skin test reaction in tuberculoid leprosy patients and healthy contacts. In contrast, Dharmendra preparation of BCG induced marked T-cell response in tuberculoid as well as bacterial index negat ive lepromatous patients. DCC induced a significantly higher lymphopro liferative response than Dharmendra lepromin in all study groups. A si gnificant positive correlation was observed between the lymphoprolifer ative responses to DCC and BCG. The present study, based on a large nu mber of leprosy patients and healthy contacts, clearly demonstrates th at DCC, depleted of glycolipids and lipopolysaccharides, is a good ant igenic preparation for evaluating T-cell reactivity to M. leprae.