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Vascular pathology in dermatomyositis and anatomic relations to myopathology
Author(s) -
Pestronk Alan,
Schmidt Robert E.,
Choksi Rati
Publication year - 2010
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.21651
Subject(s) - dermatomyositis , atrophy , pathology , myocyte , muscle atrophy , medicine , connective tissue , anatomy
Abstract The causes of perifascicular myofiber atrophy and capillary pathology in dermatomyositis are incompletely understood. We studied 11 dermatomyositis muscles by histochemistry, immunohistochemistry, and ultrastructure. We found that endomysial capillaries within regions of perifascicular atrophy are not entirely lost, but they have reduced size, endothelial loss, C5b9 complement deposits, and relatively preserved connective tissue molecules and pericytes. In all muscles, the perimysium varies regionally. Some areas contain intermediate‐sized vessels. Others are avascular. In dermatomyositis, vascular perimysium contains abnormal vessel fragments, perivascular inflammation, and increased PECAM‐1. Perifascicular myofiber atrophy and capillary pathology are concentrated near the avascular perimysium. We conclude that both perimysial intermediate‐sized vessels and endomysial capillaries within regions of perifascicular myofiber atrophy are abnormal in dermatomyositis. Capillary damage and myofiber atrophy are concentrated in regions distant from intermediate‐sized perimysial vessels. Chronic immune vascular damage and insufficiency in dermatomyositis may cause ischemia, myofiber atrophy, and capillary damage in “watershed” regions of muscle near the avascular perimysium. Muscle Nerve, 2010