Inflammatory myopathies after allogeneic stem cell transplantation.

Unlabelled: Introduction,: Graft-versus-host disease (GVHD) is a recognized complication of allogeneic stem cell transplantation (allo-SCT) and may affect muscle. We investigated the incidence and subtypes of inflammatory myopathy (IM) in South Australian recipients of allo-SCT.

Methods: Recipients of allo-SCT from 2004 to 2014 at the Royal Adelaide Hospital were identified. Records were reviewed to identify patients with weakness, creatine kinase (CK) elevation, and muscle biopsy confirming IM.

Results: Weakness was present in 32 of 224 patients who received allo-SCT patients reviewed, and CK was raised in 7 of 20 patients with weakness. Six patients developed biopsy-confirmed IM; 3 patients had chronic GVHD-related myopathy, 2 had necrotizing myopathy, and 1 had dermatomyositis (DM) associated with anti-melanoma differentiation associated protein 5 (MDA5) antibodies. The incidence of IM was calculated to be 2 cases per thousand annually.

Discussion: Among recipients of allo-SCT, weakness is common, and the incidence of IM is increased. Histopathological diagnoses are varied, and we report findings of necrotizing myopathy and anti-MDA5-associated DM. Muscle Nerve 58:790-795, 2018.