The role of therapeutic plasma exchange in clinically amyopathic dermatomyositis with MDA ‐5 antibody: A case report and review of the literature

Clinically amyopathic dermatomyositis (CADM) is a rare, aggressive variant of dermatomyositis associated with interstitial lung disease (ILD) and refractoriness to immunosuppressants. Antibodies against melanoma differentiation‐associated gene 5 (MDA‐5) are often found in patients with CADM. We report a patient with advanced CADM with ILD and MDA‐5 antibodies who failed to improve with immunosuppressants. We performed 2 TPE over 3 days, using 5% albumin as replacement fluid. Although five total TPE were planned, he was transferred for lung transplant evaluation after the second TPE; he died 16 days after transfer without receiving a transplant. A literature review identified four patients with CADM and MDA‐5 antibodies treated with TPE; all experienced symptomatic improvement of their ILD. We attribute our patient's outcome to the advanced nature of his disease rather than a failure of TPE. Additional research may indicate a possible reclassification of CADM with MDA‐5 antibodies in future ASFA guidelines.