Alternate Anti-Leprosy Regimen for Multidrug Therapy Refractory Leprosy: A Retrospective Study from a Tertiary Care Center in North India

Role of histopathological, serological and molecular findings for the early diagnosis of treatment failure in leprosy

BACKGROUND

Treatment failure (TF) in leprosy following multidrug therapy (MDT) presents a significant challenge. The current World Health Organization (WHO) fixed-duration MDT regimen, based on lesion count, might not be adequate. Leprosy lacks clear-cut objective cure criteria, and the predictive value of post-MDT histopathological findings remains uncertain. This study aims to identify predictive factors for TF among leprosy patients who have completed the WHO-recommended MDT.

METHODS

An analysis was conducted on 80 individuals from a national leprosy reference center, comprising 40 TF cases (with a mean relapse at 13.0 months) and 40 controls (with a mean of 113.1 months without disease signs). Various epidemiological and clinical-laboratory parameters were assessed post-MDT.

RESULTS

In skin samples, the presence of foamy granuloma (OR = 7.36; 95%CI2.20-24.60; p = 0.0012) and histological bacillary index (hBI) ≥ 1+ (OR = 1.55; 95%CI1. 22-1.99; p = 0.0004) were significantly associated with TF, with odds ratios of 7.36 and 1.55, respectively. Individuals who experienced TF had a mean hBI of 3.02+ (SD ± 2.02), while the control group exhibited a mean hBI of 1.8+ (SD ± 1.88). An hBI ≥ 3 + showed a sensitivity of 73% and a specificity of 78% for TF detection (AUC: 0.75; p = 0.0001). Other histopathological features like epithelioid granulomas, and skin changes did not show significant associations (p > 0.05). Additionally, higher anti-phenolic glycolipid-I (anti-PGL-I) ELISA index (EI) levels were linked to a 1.4-fold increased likelihood for TF (OR = 1.4; 95%CI1.13-1.74; p = 0.0019). A mean EI of 4.48 (SD ± 2.80) was observed, with an EI ≥ 3.95 showing a sensitivity of 79% and a specificity of 59% for TF detection (AUC: 0.74; p = 0.0001). Moreover, the presence of Mycobacterium leprae (M. leprae) DNA in real-time polymerase chain reaction (qPCR) was associated with a 3.43-fold higher likelihood of TF. Multivariate regression analysis indicated that concurrent presentation of neural/perineural lymphocytic infiltrate, foamy granuloma, hBI ≥ 1+, and EI ≥ 1 markedly increased the likelihood of TF by up to 95.41%.

CONCLUSION

Persistence of nerve-selective lymphocytic infiltrate, foamy granulomas, and bacilli in skin biopsies, and elevated EI post-MDT, may serve as predictive factors for identifying individuals at higher probability of TF.

Exploring the therapeutic and prophylactic potential of bedaquiline in leprosy

Leprosy remains a significant public health concern despite major strides in treatment and control efforts. The Global Leprosy Strategy 2021-2030 and the National Strategic Plan for Leprosy 2023-2027 majorly focus on facilitating action to reach the goal of zero leprosy. Exploration of new treatment regimens is emphasized as one of the verticals of the multipronged approach for reaching the aforementioned goals. This becomes particularly pertinent in the wake of growing evidence for resistance to the drugs currently being used in the management of leprosy. Repurposed molecules present a very good approach in this direction. The present review aims to explore the potential of bedaquiline, a drug used for multidrug-resistant tuberculosis, as a potential addition to the therapeutic armamentarium of leprosy. Through this narrative review, the authors attempt to look into the available proof of concept, clinical evidence, potential risks, and possible ways forward with bedaquiline in leprosy.

A challenging case of borderline lepromatous leprosy non-responsive to WHO-MDT: exploring approaches beyond WHO-MDT

Just as we prioritize personalized medicine for various other medical conditions, we should also include a neglected disease like leprosy, ensuring that patients receive the best care possible and improving their quality of life. Our case highlights the importance of instituting an alternate therapeutic regimen in a scenario where there is a lack of clinical response to multidrug therapy, even in the absence of documented drug resistance of the currently available molecular diagnostics. The search for the perfect regimen tailored for each individual leprosy patient should continue. Alternate anti-leprosy therapy is highly useful in cases with confirmed drug resistance or clinically non-responsive cases; however, their misuse should also be strictly avoided to prevent the development of resistance to them.

Reverse Koebner phenomenon in erythema nodosum leprosum

BACKGROUND

Erythema nodosum leprosum (ENL) is an immunologically mediated phenomenon complicating the course of leprosy. Reverse Koebner phenomenon is the term used to describe the sparing of previously injured or diseased skin by new skin lesions of the disease.

METHODS

A middle-aged woman with a known case of lepromatous leprosy for the past year presented with an eruption of reddish painful nodules over her body. The lesions were found to characteristically spare the sites of previous scars.

RESULTS

This sparing phenomenon of previous scar sites has been termed reverse Koebner phenomenon, a site of the body that offers greater resistance than the rest of the body to the onset of the disease, seen in various diseases, but it has never been described in ENL.

CONCLUSION

This sparing of scar sites in ENL can be attributed to reverse Koebner phenomenon.

High frequency of ofloxacin resistance patterns of Mycobacterium leprae from India: An indication to revisit second line anti-leprosy treatment regimen

OBJECTIVES

Drug resistance in leprosy is an emerging concern, leading to treatment failures, recurrences, and potential spread of resistant Mycobacterium leprae in the community. In this study, we aimed to assess drug resistance prevalence and patterns amongst leprosy patients at a tertiary care referral hospital in India.

METHODS

Mutations in drug resistance determining regions for dapsone, rifampicin, and ofloxacin of the M. leprae genome in DNA extracted from skin biopsies of 136 leprosy patients (treatment-naive = 67, with persistent skin lesions = 35, with recurrence = 34) were analysed by polymerase chain reaction followed by Sanger sequencing. Wild-type strain (Thai-53) was used as a reference strain.

RESULTS

Resistance mutations were identified in a total of 23 patients, constituting 16.9% of the cohort. Within this subset of 23 cases, resistance to ofloxacin was observed in 17 individuals (12.5%), while resistance to both dapsone and rifampicin was detected in three patients each (2.2% for both). The occurrence of ofloxacin resistance showed minimal disparity between recurrent and treatment-naive cases, at 17.6% and 16.4%, respectively. Dapsone resistance emerged in two treatment-naive cases and one case with persistent skin lesions. Notably, none of the treatment-naive cases or those with recurrence/relapse exhibited rifampicin resistance. Subsequently, no statistically significant correlation was identified between other clinical variables and the presence of antimicrobial resistance.

CONCLUSIONS

The occurrence of resistance to the current multidrug therapy regimen (specifically dapsone and rifampicin) and to ofloxacin, a secondary antileprosy medication in M. leprae, represents a concerning scenario. This calls for an expansion towards bactericidal drug options and the establishment of robust surveillance for drug resistance in countries burdened with high leprosy rates. Moreover, the introduction of stringent antimicrobial stewardship initiatives is imperative. As a single centre study, it represents a limited, cross-sectional view of the real situation in the field.

Equal rates of drug resistance in leprosy cases with relapse and recurrent /chronic type 2 reaction; Time to revise the guidelines for drug resistance testing in leprosy

BACKGROUND

Leprosy relapse/recurrence is a serious concern especially in a leprosy endemic nation like India. It is believed that bacilli persisting even after multi-drug therapy could cause relapse; recently however drug resistance as a cause for recurrences and chronic erythema nodosum leprosum (ENL) has been speculated. Our objective was to study drug resistance patterns in cases of leprosy relapse and chronic/recurrent ENL's.

METHODOLOGY

This cross-sectional study conducted over a period of 1 year included patients diagnosed as leprosy relapse and those with chronic/recurrent (c/r) ENL. Skin biopsy specimens were subjected to conventional PCR for resistance testing for rifampicin, dapsone and ofloxacin, targeting rpoB, folP and gyrA gene of M.leprae respectively.

RESULTS

A total of 61 patients (25 smear negative) were included in the study. Of these, 37 were diagnosed as leprosy relapse and 24 had c/r ENL. Drug resistance to at least one drug was identified in 10 (16.4%) cases. Rates of drug resistance were 5.4% (2/37) for dapsone, 10.8% (4/37) for rifampicin and 2.7% (1/37) for ofloxacin amongst cases of relapse where as it was 12.5% (3/24) and 8.3% (2/24) for dapsone and rifampicin respectively amongst those with c/rENL.. Multi drug resistance was seen in 3.3% (2/61) patients.

CONCLUSION

Drug resistance rate amongst those with c/rENL was almost equaled that of relapse. Smear negative leprosy relapse cases also had resistance to bactericidal drugs. These findings call for modifications in criteria for testing under leprosy drug resistance surveillance and all cases of relapse and those with recalcitrant c/rENL should be tested.

Persistent plaques after release from treatment in slit-skin smear negative leprosy patients: Wait and watch or adopt a proactive approach?

A subset of leprosy patients has clinical and histopathological activity in the form of persistent plaques and granulomas after completion of multidrug therapy (MDT) which can have significant impact on their quality of life. In the absence of clear guidelines regarding management of such patients, majority of the times they are treated either as late reversal reaction with corticosteroids or no active treatment is offered. We observed 11 patients of leprosy with persistent plaques after completing the 6/12-months MDT who were treated favorably with minocycline 100 mg once daily for 16 weeks. Complete clinical resolution was observed in 9/11 patients while two patients had partial improvement. Histopathological improvement in the form of disappearance of granulomas corroborated with the clinical improvement. All the patients tolerated the treatment well and hyperpigmentation was the only adverse effect noted. Minocycline may be considered as a useful and well tolerated therapeutic option for this subset of leprosy patients due to its immune modulatory and anti-inflammatory effects.

Clofazimine: an old drug for never-ending diseases

Clofazimine (CFZ), an old hydrophobic riminophenazine, has a wide range of antimycobacterial activity ranging from leprosy to nontuberculous mycobacterial diseases. CFZ has several advantages such as a favorable pharmacokinetic profile, dose-dependent side effects as well as low price. In this narrative review, we have assessed the clinical development of CFZ, starting from the potential in vitro mechanism of actions, to the spectrum of side effects and potential drug-drug interactions, highlighting its current place in therapy and future possible use in leprosy, nontuberculous mycobacterial diseases and drug-resistant tuberculosis.

Metabolism and interactions of antileprosy drugs

Leprosy is a chronic infectious disease caused my Mycobacterium leprae that primarily affects peripheral nervous system and extremities and is prevalent in tropical countries. Treatment for leprosy with multidrug regimens is very effective compared to monotherapy especially in multibacillary cases. The three major antileprosy drugs currently in use are 4, 4'-diaminodiphenyl sulfone (DDS, dapsone), rifampicin, and clofazimine. During multidrug therapy, the potent antibiotic rifampicin induces the metabolism of dapsone, which results in decreased plasma half-life of dapsone and its metabolites. Furthermore, rifampicin induces its own metabolism and decreases its half-life during monotherapy. Rifampicin upregulates several hepatic microsomal drug-metabolizing enzymes, especially cytochrome P450 (CYP) family that in turn induce the metabolism of dapsone. Clofazimine lacks significant induction of any drug-metabolizing enzyme including CYP family and does not interact with dapsone metabolism. Rifampicin does not induce clofazimine metabolism during combination treatment. Administration of dapsone in the acetylated form (acedapsone) can release the drug slowly into circulation up to 75 days and could be useful for the effective treatment of paucibacillary cases along with rifampicin. This review summarizes the major aspects of antileprosy drug metabolism and drug interactions and the role of cytochrome P450 family of drug metabolizing enzymes, especially CYP3A4 during multidrug regimens for the treatment of leprosy.