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Morphometric analysis of nerve fibers in neural leprosy
Author(s) -
Antunes Sérgio Luiz Gomes,
Fazan Valéria Paula Sassoli,
Jardim Márcia Rodrigues,
Santos Pereira Mário José,
Costa Eduardo Alves Freire,
Pascarelli Bernardo Oliveira,
Hacker Mariana Andrea Vilasboas,
Sarno Euzenir Nunes,
Barreira Amilton Antunes
Publication year - 2021
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.27152
Subject(s) - leprosy , wallerian degeneration , axon , nerve biopsy , medicine , atrophy , pathogenesis , pathology , degeneration (medical) , axonal degeneration , anatomy , peripheral neuropathy , endocrinology , diabetes mellitus
Background The present study assesses the contributions of axonal degeneration and demyelination in leprosy nerve damage. New clinical strategies can emerge from an in‐depth understanding of the pathogenesis of neural leprosy (NL). Methods Morphometric analysis of myelinated nerve fibers was performed on 44 nerve biopsy samples collected from leprosy patients. Measures of density, diameter distribution, g‐ratios, and the counting of axonal ovoids on the myelinated fibers were taken and compared to those in the control group. Results The proportion of small myelinated fibers increased in the leprosy group while large fiber frequency decreased. Indicative of axonal atrophy, the g‐ratio was lower in the leprosy group. The frequency of axonal ovoids was identical to that found in the non‐leprosy neuropathies. Conclusions Axonal atrophy, Wallerian degeneration, and demyelination coexist in NL. Axonal degeneration predominates over demyelination in the chronic course of the disease; however, this may change during leprosy reactive episodes. This study regards demyelination and axon degeneration as concurrent mechanisms of damage to nerve fibers in leprosy. It also calls into question the view that demyelination is the primary and predominant mechanism in the complex pathogeny of NL.