A LONGITUDINAL-STUDY OF IMMUNOLOGICAL REACTIVITY IN LEPROSY PATIENTS TREATED WITH IMMUNOTHERAPY

More than 150 leprosy patients treated with multidrug therapy (MDT) pl us immunotherapy (IMT) with a mixture of heat-killed Mycobacterium lep rae plus live BCG were studied in relation to humoral and cell-mediate d immune responses. Many previously had received prolonged sulfone mon otherapy. Patients received 2 to 10 doses of IMT in a period of 1 to 3 years, depending upon their clinical form of leprosy. The patients we re followed up for 5 to 10 years with repeated determinations of antib ody levels to phenolic glycolipid-I; lymphoproliferative (LTT) respons es to soluble extract of M. leprae, to whole bacilli and to BCG, skin- test responses and bacterial indexes (BIs). After MDT plus IMT there w as a statistically significant decrease of antibody levels in the mult ibacillary (MB) group. The BI decreased proportionally to the ELISA re sults. LTT increased to M. leprae antigens, especially to soluble extr act, in a high percentage of these patients (34% of LL patients positi ve). Lepromin positivity in MB patients increased from 5% initially po sitive to 75% at the cut-off during this follow up. These results show substantial early and persistent cell-mediated reactivity to M. lepra e in many MB patients treated with MDT-IMT, confirming and expanding p reviously published data.