Immunotherapy may be a useful tool in the management of leprosy, especially in highly bacillated patients because of immunological memory. This open-label randomized controlled trial assessed changes in the molecular viability assay (esxA and hsp18 transcript expression) and serology (anti-ND-O-BSA levels) in patients with multibacillary leprosy treated with multibacillary multidrug therapy (MB-MDT) with Mycobacterium indicus pranii (MIP) vaccine or MB-MDT with bacille Calmette–Guérin (BCG) vaccine. Secondary outcomes were changes in histopathological parameters (granuloma fraction and bacillary index of the granuloma), differences in the incidences of type 1 and type 2 lepra reactions, and incidence of immunotherapy-associated adverse drugs reactions among the two groups. The study included 40 patients with multibacillary leprosy randomized into the MIP + MB-MDT and BCG + MB-MDT groups. Thirty patients (15 in each group) completed the 12-month follow-up. Molecular viability assays based on esxA and hsp18 transcript expression, and anti-NO-O-BSA levels were measured in 23 of 30 patients (13 in the MIP group and 10 in the BCG group). In the MIP group, 77% of patients (10 of 13) and in the BCG group, 50% (5 of 10) showed decreased esxA (P = 0.09) and hsp18 transcript expression (P = 0.4). The median decrease in bacteriological index was 1 (interquartile range 0–2) in the MIP group and 1 (interquartile range 0–1) in the BCG group (P = 0.9). A decrease in IgM anti-ND-O-BSA levels was seen in 77% of patients (10 of 13) in the MIP group and 80% (8 of 10) in the BCG group (P = 0.9). Histopathological upgrading was noted in 85% of patients (11 of 13) in the MIP group and 90% (9 of 10) in the BCG group (P = 0.3). Most of the patients had clinical improvement (26 of 30, 87%), which was comparable between the two groups (P = 0.5). None of these patients had primary drug resistance to the first-line MDT drugs. Two patients in the MIP group (13%) and five in the BCG group (33%) had reactional episodes, but only one had an increase in disability. The adverse effect profiles of both vaccines were similar, the majority being injection-site reactions. BCG was associated with neuritis in two patients (12%). This study demonstrates the usefulness of immunotherapy in reducing bacillary viability, improving histopathological and serological markers, and potentially preventing lepra reactions and associated disability. The comparability of MIP and BCG is noteworthy, especially considering BCG’s wider availability and lower cost. The use of molecular viability assays and anti-ND-O-BSA enzyme-linked immunosorbent assay as diagnostic and predictive tools for reactions and/or relapse could advance future research in leprosy.
a0007-0963, 1365-2133