Clinical and pathogenetic implications of histopathology in childhood polydermatomyositis

Abstract

Childhood dermatomyositis is a distinct subset of dermatomyositis with highly variable outcome. We reviewed our experience with 29 patients observed over a period of 22 years and attempted to correlate tissue manifestations with outcome. Distinctive vascular lesions included non-necrotizing lymphocytic vasculitis and a unique spectrum of endovascular injury producing temporary or permanent occlusion of small arteries and capillaries. Vessels with nonineammatory endovasculopathy were often reactive with fluorescein-conjugated antisera to IgM, C3d, and/or fibrin. Lesions linked to endovascular injury include infarction, zonal myopathy , and loss of capillary network. We were able to identify half of the children destined to have persistent morbidity on the basis of severity of vasculopathy in pretreatment muscle-biopsy specimens. Our observations support a central role for endothelial cell injury in the pathogenesis of childhood dermatomyositis, suggest a basis for

Late‐onset gastrointestinal pain in juvenile dermatomyositis as a manifestation of ischemic ulceration from chronic endarteropathy

“…intimal hyperplasia and occlusion of vessels by fibrin thrombi in the submucosa, muscularis, and serosal layers (2,3). This is in contrast to our patients, who showed a chronic vasculopathy rather than an acute vasculitis.…”

“…Gastrointestinal manifestations of juvenile DM include dysphagia, bowel dysmotility, and vasculitis with associated malabsorption (1). Gastrointestinal ulceration is thought to be characteristic of the vasculopathy associated with juvenile-onset DM, rather than adult-onset DM, and might uncommonly lead to intestinal perforation (2). An autopsy series of patients with juvenile DM from the 1960s, prior to the optimal use of corticosteroids and other immunosuppressive agents, demonstrated frequent ulceration, perforation, and vascular changes in the bowels of patients with juvenile DM (3).…”

Association between lack of angiogenic response in muscle tissue and high expression of angiostatic ELR‐negative CXC chemokines in patients with juvenile dermatomyositis: Possible link to vasculopathy

“…The poor repair of such damage eventually leads to loss of the capillary network, associated with perifascicular atrophy of both type I and type II fibers (1)(2)(3). Similar changes are observed in the affected skin and gastrointestinal tract, leading to ulcerative complications in 20-30% of juvenile DM patients (1,2). The reason for the impaired blood vessel repair is poorly understood.…”

“…Although myositis is the main clinical feature of this disease, many rheumatologists view juvenile DM as a systemic vasculopathy rather than simply an inflammation of muscle and skin (1,2). In fact, in 1975 Bohan and Peter distinguished juvenile DM from all other inflammatory myopathies based primarily on this feature (1).…”

Dermatomiositis juvenil: manifestaciones clínicas y de laboratorio

“…En ellos la vasculitis es responsable de la mayoria de las manifestaciones ch'nicas, es rara su asociacion a neoplasias y muestra alta incidencia de calcinosis distroficas en las etapas tardi'as 2 " 7 .…”