Immune Checkpoint Inhibitor–Associated Myositis

Abstract

Research on the relationship between inflammatory myopathy and malignancy has grown considerably within the last century. Now, the burgeoning field of inflammatory myopathy has yet another player in the mix: immune checkpoint inhibitor-associated myositis (ICI myositis). Immune checkpoint inhibitor-associated myositis is indicated by clinical diagnosis of inflammatory myopathy after initiation of immune checkpoint inhibitor for cancer management. Current literature reflects low prevalence but high mortality associated with ICI myositis, especially when involving myasthenia gravis and myocarditis. Immune checkpoint inhibitor-associated myositis tends to have muscle pain along with weakness, infrequent presentation with dermatitis, or interstitial lung disease and is typically seronegative with scattered, endomysial inflammatory infiltrates on biopsy. The differential diagnosis of ICI myositis includes myasthenia gravis and other neurological immune-related adverse events. Therapeutic approach involves high doses of corticosteroids with a choice of steroid-sparing immunomodulating agent(s) that is primarily driven by expert opinion due to lack of robust research to support one agent over another. There is wide variation in the inclusion criteria for ICI myositis used in previous studies. We review previously used inclusion criteria and suggest an expertise-based classification criterion to provide a standardized definition and allow comparability between studies. There is a critical need for prospective translational and clinical studies that elucidate the pathophysiology of ICI myositis in order to improve evaluation and management of these patients.

Predictors and Risk Score for Immune Checkpoint-Inhibitor-Associated Myocarditis Severity

“…Respiratory muscle failure was included to reflect contemporary understanding of ICI-myocarditis as part of a generalized skeletal myositis that can impair ventilation. 5 , 8 , 16 , 17 The study period ended 30 days after clinical presentation with ICI-myocarditis to avoid including unrelated endpoints. Cases were excluded if the primary outcome was met more than 24 hours prior to presentation (n=9), leaving 748 cases for analysis.…”

Dermatomyositis, Antisynthetase-Syndrom und immunvermittelte nekrotisierende Myopathie

“…Aktuell laufen ferner diverse weitere klinische Studien hinsichtlich der Myositis-Therapie mit neuen Therapieoptionen, allerdings werden gerade vor diesem Hintergrund Stimmen nach erneuerten Diagnosekriterien sowie angepassten Outcome-Parametern je nach zugrunde liegender Myositis-Entität und Organbeteiligung laut 87 .…”