02695nas a2200301   4500000000100000008004100001260001200042100001500054700001400069700001200083700001200095700002200107700001700129700001400146700001100160700002800171700001900199700001600218700001200234700001500246700001700261700001300278700001500291700001300306245016000319520190000479022001402379       2020                            d  c04/20201 aVengalil S1 aLavania M1 aSingh I1 aNashi S1 aPreethish-Kumar V1 aPolavarapu K1 aMahajan N1 aRaju S1 aPradeep-Chandra-Reddy C1 aKeerthipriya M1 aMahadevan A1 aYasha T1 aNandeesh B1 aGnanakumar K1 aParry GJ1 aSengupta U1 aNalini A00aAppropriately Selected Nerve in Suspected Leprous Neuropathy Yields High Positive Results for Mycobacterium leprae DNA by Polymerase Chain Reaction Method.3 a<p>Identification of  DNA by polymerase chain reaction (PCR) is a reliable and an affordable method to confirm leprosy. DNA from 87 nerve samples (56 from paraffin blocks and 26 fresh samples) was extracted.  DNA was amplified by PCR from 80/87 (92%) specimens. Patients were seen over a period of 11 years (2007-2019), and leprosy was diagnosed based on clinical and characteristic histopathology findings. The clinical diagnostic possibilities were as follows: leprous neuropathy in 73/80 (91.3%), mononeuritis multiplex of unknown etiology in four (5.0%), vasculitic neuropathy in two (2.5%), and distal symmetric sensory motor neuropathy in one (1.3%). The biopsied nerves were as follows: superficial radial = 34 (42.6%), dorsal cutaneous branch of ulnar = 19 (23.8%), sural = 18 (22.5%), and superficial peroneal = 9 (11.3%), and corresponding neurological deficits were recorded in 77 (96.3%) cases. The histopathological diagnoses in total group were as follows: (borderline tuberculoid = 52, TT = 8, BL = 8, BB = 3, nonspecific inflammation = 3, healed/fibrosed = 4, and axonopathy = 2). AFB was demonstrated in 11 (13.7%) samples. For comparison, 31 clinically and histopathologically defined non-leprous disease control nerves (inherited neuropathy = 20, vasculitis = 8, and nutritional neuropathy = 3) subjected to PCR were negative for  DNA. In most instances, there are multiple thickened peripheral nerves in suspected cases of leprosy, but neurological deficits pertaining to the thickened nerve are not as widespread. The current findings emphasize the importance of selecting the most appropriate nerve for biopsy to obtain a positive PCR result. We infer that clinical, histopathological, and PCR tests complement each other to help achieve a definitive diagnosis of leprosy particularly in pure neuritic leprosy and in leprous neuropathy with negative skin smears/biopsy.</p>  a1476-1645