Lepromatous leprosy is associated with suppressed cell-mediated immunity (CMI). This results in failure of the body to mount an efficient immune response and may render chemotherapy ineffective. The lack of sufficient response may mimic drug resistance. Three case reports in which the immunity was stimulated by administering Injection BCG are presented. All three patients were initially anergic and showed no reaction at the Mantoux testing site, showing an inability to mount type IV hypersensitivity and characterized by live bacilli in smears. Following 1-4 doses of Injection BCG, all three showed dead bacilli in smears.
The first case, a 61-year-old man with lepromatous leprosy who continued to show live bacilli in smears after prolonged chemotherapy, was administered a total of four BCG injections, following which he achieved clearance. The second, a 40-year-old man with borderline lepromatous leprosy and severe type 2 reactions, achieved bacterial clearance and control of severe reactions following a single injection. The third, a 67-year-old man with histoid leprosy, achieved effective bacterial killing with a single dose of Injection BCG.
All three patients achieved good results when chemotherapy was combined with Injection BCG. Following Injection BCG, all three showed a reaction at the Mantoux testing site.
Suppressed CMI may be responsible for the lack of response in recalcitrant cases of lepromatous leprosy. These case reports would lead to the trend in combination therapy (immunotherapy combined with chemotherapy) for such cases, and help lower the tendency for inappropriate diagnosis of drug-resistant leprosy.