title: HMGCR-associated myositis: a New Zealand case series and estimate of incidence.
abstract: Statins are one of the most commonly prescribed drugs in New Zealand, with 525 772 or 16.5% of the adult New Zealand population prescribed a statin between June 2013 and July 2014. While generally well-tolerated, statins are known to cause a range of muscle-related side effects, ranging from myalgia to life-threatening rhabdomyolysis. Recently, it has been recognised that in rare instances, statins can induce an immune-mediated necrotising myositis with antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the enzymatic target of statins. In 2014, anti-HMGCR antibody testing was introduced to Canterbury Health Laboratories (CHL), with this being the only laboratory in New Zealand performing this test during the period of this case series. This article describes an index case and characterises the clinical features of a subsequent 12-month series. From this series, we estimated the yearly incidence of HMGCR-associated myositis at 1.7/million/year or ~1/90 000 New Zealand statin users.
authors.affiliation: Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: N
authors.initials: N
authors.lastname: Kennedy
authors.affiliation: Canterbury Health Laboratory, Addington, New Zealand.
authors.forename: P
authors.initials: P
authors.lastname: Keating
authors.affiliation: Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, Christchurch, New Zealand.|Canterbury Health Laboratory, Addington, New Zealand.
authors.forename: J
authors.initials: J
authors.lastname: O'Donnell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology; D005260:Female; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000276:immunology*; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000139:chemically induced* / Q000453:epidemiology*; D009520:New Zealand / Q000453:epidemiology
chemical_list: D001323:Autoantibodies; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D006903:Hydroxymethylglutaryl CoA Reductases
keywords: HMCGR; autoantibody; autoimmune; myositis; statin