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Microfasciculation: a morphological pattern in leprosy nerve damage
Author(s) -
Antunes Sérgio L G,
Medeiros Mildred F,
CorteReal Suzana,
Jardim Márcia R,
Nery José A da Costa,
Hacker Mariana A V B,
Valentim Vânia da Costa,
Amadeu Thaís Porto,
Sarno Euzenir N
Publication year - 2011
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/j.1365-2559.2011.03749.x
Subject(s) - perineurium , pathology , leprosy , neuritis , immunohistochemistry , endoneurium , axon , schwann cell , biology , nerve biopsy , biopsy , histopathology , anatomy , medicine , peripheral neuropathy , sciatic nerve , peripheral nerve , neuroscience , endocrinology , diabetes mellitus
Antunes S L G, Medeiros M F, Corte‐Real S, Jardim M R, da Costa Nery J A, Hacker M A V B, da Costa Valentim V, Amadeu T P & Sarno E N
(2011) Histopathology 58, 304–311 Microfasciculation: a morphological pattern in leprosy nerve damage Aims: To study Microfasciculation, a perineurial response found in neuropathies, emphasizing its frequency, detailed morphological characteristics and biological significance in pure neural leprosy (PNL), post‐treatment leprosy neuropathy (PTLN) and non‐leprosy neuropathies (NLN). Methods and results: Morphological characteristics of microfascicles were examined via histological staining methods, immunohistochemical expression of neural markers and transmission electronmicroscopy. The detection of microfasciculation in 18 nerve biopsy specimens [12 PNL, six PTLN but not in the NLN group, was associated strongly with perineurial damage and the presence of a multibacillary inflammatory process in the nerves, particularly in the perineurium. Immunoreactivity to anti‐S100 protein, anti‐neurofilament, anti‐nerve growth receptor and anti‐myelin basic protein immunoreactivity was found within microfascicles. Ultrastructural examination of three biopsies showed that fibroblast–perineurial cells were devoid of basement membrane despite perineurial‐like NGFr immunoreactivity. Morphological evidence demonstrated that multipotent pericytes from inflammation‐activated microvessels could be the origin of fibroblast–perineurial cells. Conclusions: A microfasciculation pattern was found in 10% of leprosy‐affected nerves. The microfascicles were composed predominantly of unmyelinated fibres and denervated Schwann cells (SCs) surrounded by fibroblast–perineurial cells. This pattern was found more frequently in leprosy nerves with acid‐fast bacilli (AFB) and perineurial damage while undergoing an inflammatory process. Further experimental studies are necessary to elucidate microfascicle formation.