RT Journal Article SR Electronic T1 Anti-HMGCR Autoantibodies in Juvenile Idiopathic Inflammatory Myopathies Identify a Rare but Clinically Important Subset of Patients JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.160871 DO 10.3899/jrheum.160871 A1 Sarah L. Tansley A1 Zoe E. Betteridge A1 Stefania Simou A1 Thomas S. Jacques A1 Clarissa Pilkington A1 Mark Wood A1 Kishore Warrier A1 Lucy R. Wedderburn A1 Neil J. McHugh YR 2017 UL http://www.jrheum.org/content/early/2017/02/09/jrheum.160871.abstract AB Objective We aimed to establish the prevalence and clinical associations of anti-HMG-CoA-reductase (anti-HMGCR) in a large UK cohort with juvenile myositis. Methods There were 381 patients investigated for anti-HMGCR using ELISA. Results Anti-HMGCR autoantibodies were detected in 4 patients (1%). These children had no or minimal rash and significant muscle disease. Muscle biopsies were considered distinctive, with widespread variation in fiber size, necrotic fibers, and chronic inflammatory cell infiltrates; all had prolonged elevation of creatine kinase and all ultimately received biologic therapies. Conclusion Anti-HMGCR in UK children with myositis are associated with severe disease that is poorly responsive to standard treatment.