BCG immunotherapy as an adjunct to chemotherapy in BL-lL patients--its effect on clinical regression, reaction severity, nerve function, lepromin conversion, bacterial/antigen clearance and 'persister' M. leprae.

BACKGROUND AND OBJECTIVE: Multidrug therapy in leprosy has failed to eliminate the problem of persister bacilli. Clearance of bacterial antigens is extremely slow which could predispose to continued nerve damage even after release from treatment. In the present study the immunomodulatory efficacy of BCG vaccine administered post-MDT in BL-LL leprosy patients was investigated in depth with a view to determining if augmenting chemotherapy with immunotherapy would help in faster clearance of M. leprae/antigens, bring down the level of persisters and minimise the occurrence/severity of reaction and nerve damage. METHODS: This is a placebo-controlled study in treated BL-LL patients. The patients are matched with respect to age, sex, bacteriological index and history of reaction, stratified and allocated to the two groups. One group (Gr A) received two doses of BCG-MOSCOW (3-33 x 10(5) cells) and the other (Gr B) normal saline (0.85%), injected intra-dermally at 3 month intervals. The Primary outcomes assessed at the end of 6 months were bacterial/antigen clearance, lepromin conversion, granuloma clearance and the occurrence of persisters. The secondary outcomes were clinical regression, occurrence and severity of reaction and changes in nerve functions. MATERIAL: A total of 107 BL-LL patients comprised of 49 in Gr A and 58 in Gr B; of which 36 and 42 respectively completed the study as per protocol, and are included in the final analysis. FINDINGS: The study findings show that both the primary and the secondary out comes were comparable in the two groups. Two doses of BCG administered post-MDT (Gr A) did not significantly alter the level of persisters or help in hastening the bacterial/antigen clearance, clinical regression of lesions and granuloma clearance. Lepromin conversion rates were also comparable. While the frequency of lepra reaction/neuritis following the intervention was comparable, the severity of reactions was significantly higher in Gr A. On the positive side neural functions assessed by nerve conduction studies showed that deterioration of motor nerve conduction was significantly lower in the BCG arm. Since all patients developing moderate to severe reactions, immediately received a course of corticosteroids, it is possible that timely use of it might have helped.

The effect of corticosteroids usage on bacterial killing, clearance and nerve damage in leprosy; part 3--Study of two comparable groups of 100 multibacillary (MB) patients each, treated with MDT + steroids vs. MDT alone, assessed at 6 months post-release from 12 months MDT.

OBJECTIVE: To investigate effects of therapeutic usage of corticosteroids on M. leprae killing and clearance, on clearance of granuloma and on nerve damage in multibacillary (MB) leprosy patients. DESIGN: From a cohort of 400 untreated MB patients, a comparable group of 100 each receiving MDT + steroids (group A) vs MDT alone (group B) were assessed at 18 months as compared to month zero with respect to clinical and granuloma regression, M. leprae killing and clearance, and nerve functions. Analysis was performed using SPSS version 10.0. The significance of association was tested using Chi square and Fisher's exact tests. RESULTS: Regression of lesions assessed clinically and by histopathology was seen in 52% and 53% patients in group A and 46% and 63% in B respectively (P not significant). Clearance of bacteria assessed by bacteriological index (BI) in slit skin smears (SSS) and extent and intensity of antigen using anti-BCG staining were also comparable in the two groups. Multiplication of M. leprae in the mouse foot pad (MFP) indicating the presence of viable bacilli was seen in 14% and 16% of SSS positive BL-LLs patients in groups A and B respectively (P not significant). The occurrence of viable M. leprae was higher among patients with repeat reaction (19%) than single (11%). Using clinical tests (nerve palpation, monofilament and voluntary muscle testing), the proportion of sensory and motor nerves showing improvement or deterioration were similar in the two groups. However using nerve conduction studies, the overall proportion of nerves showing deterioration (22%) was significantly higher than improvement (9%) (P < 0.001). CONCLUSIONS: Treatment with MDT + corticosteroids does not adversely affect the clearance of granuloma, M. leprae and/or its antigens and M. leprae killing. However the continued presence of viable bacteria in > 14% of BL-LLs patients indicate that 12 months of MDT may be insufficient for complete bacterial killing. In both groups nerve conduction studies indicated that deterioration of nerves was high suggesting, MDT + corticosteroids was not very efficacious in the prevention or reversal of nerve damage. A better immuno-modulatory drug or a modified corticosteroid regime is needed.

The effect of corticosteroid usage on the bacterial killing, clearance and nerve damage in leprosy: a prospective cohort study: part 1--study design and baseline findings of 400 untreated multibacillary patients.

OBJECTIVE: To investigate possible adverse effects of therapeutic usage of corticosteroids on the killing and clearance of M. leprae and the clearance of granuloma, in patients with multibacillary (MB) leprosy. DESIGN: A cohort of 400 untreated MB patients were sub-grouped into those to be treated with corticosteroids (prednisolone 40 mg daily tapered to 5 mg over 12 weeks) along with MB-MDT for reaction and/or neuritis or silent neuropathy (SN) of <6 months duration (group A), and those with no reaction and to be treated with MDT only (group B). Clinical, bacteriological, histopathological and neurological test findings at fixed time points were compared. Analysis was performed using SPSS version 10.0. The significance of association was tested using Chi-square test. In the current report, we describe the study design and baseline findings of 400 untreated MB patients, with special emphasis on differences between patients in groups A and B. RESULTS: At baseline, applying Ridley-Jopling classification, 39% patients were BT, 20% BB, 24% BL, 12% sub-polar LL and 5% pure neural (PN). Overall, 60% patients were slit skin smear (SSS) negative and 33% presented with disability either grades 1 or 2. Overall 140/400 (35%) patients presented with reaction and/or neuritis and 11/400 (3%) presented with SN of <6 months duration. Comparing groups A and B, the percentage of patients presenting with DG2 was significantly higher in group A (43%). By clinical tests, monofilaments (MF) and voluntary muscle testing (VMT), the percentage of patients and nerves showing functional impairment was also significantly higher in group A. However, in the more sensitive nerve conduction velocity (NCV) test, the percentage of patients that showed nerve abnormalities was closely comparable; 94% and 91% in groups A and B respectively while number of affected nerves was higher in group A. CONCLUSION: At baseline, as recorded by NCV, peripheral nerve function abnormality was observed in almost all the MB patients regardless of reaction; but among those presenting with reaction or neuritis, the nerve damage was more severe and extensive.