Mandating nerve biopsy: A step towards personalizing therapy in pure neuritic leprosy.

Pure neuritic leprosy (PNL) accounts for 5% to 10% of leprosy patients who usually present with asymmetrical neuropathy in the absence of lepra bacilli on slit-skin smears. However, nerve biopsies in PNL lack appropriate categorization in current immunologic terms. We aimed to classify nerve biopsies according to the immune spectrum of leprosy and assess the role of histologic classification of nerve biopsies in treating PNL. Patients from two tertiary care referral centres were enrolled in this incident case study. Patients presenting with mononeuropathy and multiple mononeuropathies presumably with leprosy, without skin lesions, underwent nerve biopsy and slit-skin smear examination. Amongst 78 patients with mononeuropathy, 38 were diagnosed with leprosy on nerve biopsy. Leprosy was classified as tuberculoid in 16, lepromatous in 5 and borderline in 17 patients. Lepra bacilli were present in 15 biopsies. On comparing histologic subtypes with number of nerves involved clinically, a significant number of cases with single nerve involvement showed multibacillary (BB, BL or LL) histology and vice versa. Nerve biopsy helps in diagnosing patients presenting with PNL and aids in classifying it to customize the treatment for best results. Current treatment recommendations for PNL from WHO and National Leprosy Eradication Program are based on clinical assessment only, which are likely to result in inconsistent treatment and possibly relapse in cases where histomorphology shows disparity. Inclusion of nerve biopsy to guide therapy in patients with PNL is suggested.

Evaluation of polymerase chain reaction in nerve biopsy specimens of patients with Hansen's disease.

BACKGROUND: Pure neuritic variety of leprosy (PNL) presents as peripheral neuropathy with absent skin lesions and negative skin smears. Diagnosing PNL is an uphill task as most of these patients have nonspecific changes on nerve biopsy. In such circumstances, additional molecular diagnostic tools like polymerase chain reaction (PCR) has proven to be useful in diagnosing leprosy. The present study was planned to evaluate the role of PCR in nerve biopsy specimens of patients with PNL. METHODS: Patients attending the neuromuscular clinic from January 2013 to June 2014 with mononeuropathy multiplex underwent detailed diagnostic evaluation to ascertain the cause of neuropathy. Patients where this evaluation failed to establish an etiology underwent a nerve biopsy. RESULTS: Nerve biopsy was done in 52 patients, of which 35 were diagnosed as pure neuritic leprosy. Definite leprosy with positive wade fite staining for lepra bacilli was seen in 13 patients and 22 biopsies revealed a probable leprosy without lepra bacilli being identified. PCR for M. leprae was positive in 22 patients (62%). 12 of the 13 cases with definite leprosy on histopathology were PCR positive while in the AFB negative group, PCR was positive in 10 cases. PCR had a sensitivity of 92.3%, specificity of 54.5%. The positive and negative predictive value of PCR was 54.5% and 92.3% respectively. CONCLUSIONS: PCR helps in diagnosing PNL in doubtful cases. A positive PCR increases the sensitivity of detection of M. leprae especially in cases of probable PNL group where AFB cannot be demonstrated on histopathology.

Nerve biopsy in Indian patients with mononeuropathy multiplex of undetermined etiology.

INTRODUCTION: A diagnosis of mononeuropathy multiplex (MM) requires detailed evaluation to determine etiology. We performed nerve biopsy on patients with MM in whom the etiology could not be established via other investigations. METHODS: Sixty-eight patients with MM seen between January 2013 and June 2014 underwent detailed diagnostic evaluation. Those in whom the investigations failed to establish an etiology underwent nerve biopsy. RESULTS: A diagnosis of leprosy was confirmed in 14 patients and was highly probable in 17 others. Eleven patients had vasculitic neuropathy, and in 1 patient there were amyloid deposits on nerve biopsy. CONCLUSIONS: In 43 of 68 Indian patients (63%) with MM, nerve biopsy identified a definite (26 patients) or probable (17 patients) etiology. Nerve biopsy is a valuable investigation in MM that frequently results in a diagnosis of leprosy in India. Muscle Nerve, 2016 Muscle Nerve 55: 23-27, 2017.