Cutaneous involvement in anti-HMGCR positive necrotizing myopathy. Issue 123 (September 2021)

• Record Type: Journal Article
• Authors: Williams, Barbara; Horn, Michael P.; Banz, Yara; Feldmeyer, Laurence; Villiger, Peter M.
• Is Part Of: Journal of autoimmunity. Issue 123(2021)
• Publication Date: 2021-09
• Subjects: Myositis -- HMGCR -- Necrotizing myopathy -- Connective tissue disease -- Immune-mediated necrotizing myopathy (IMNM) -- Necrotizing autoimmune myopathy (NAM) -- Statin-induced myopathy; Autoimmunity -- Periodicals; Autoimmune diseases -- Periodicals; Autoantibodies -- Periodicals; Autoimmune Diseases -- Periodicals; Auto-immunité -- Périodiques; Maladies auto-immunes -- Périodiques; Electronic journals; 616.978005
• DOI: 10.1016/j.jaut.2021.102691
• Languages: English
• ISSNs: 0896-8411

Abstract

Abstract: Objective: Anti-3-Hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) positive immune-mediated necrotizing myopathy (IMNM) is a rare disease. It is induced by exogenous substances, most often by statins. Little is known about cutaneous manifestations of HMGCR positive IMNM and about HMGCR antibody positivity in other diseases. Methods: The characteristics of patients with anti-HMGCR autoantibodies measured at our laboratory between January 2012 and September 2020 were studied. Characteristics of patients with IMNM were compared to those patients with positive antibodies but without muscle involvement. Associations of IMNM with other organ involvements were searched for. Results: Of the 32 patients studied, 23 showed characteristics of IMNM, 9 did not fulfill current classification criteria but most showed signs of connective tissue diseases. Patients with IMNM were older (66 and 35 years, respectively; 0.92 (0.73–0.98); p < 0.001), had more frequent statin exposure (87% and 33%, respectively; 0.84 (0.61–0.94); p = 0.005) and higher mean peak CK (8717U/l and 329U/l, respectively; 1.0 (0.85–1.0); p < 0.001). 13/23 (56%) of IMNM patients showed cutaneous lesions; none of the patients suffered from cancer; only three IMNM patients showed drug-free complete remission. Incidence of IMNM in the catchment area of our center is at least 2.7/Mio/year. Conclusion: Cutaneous lesions were found to be more frequent in anti-HMRCR positive IMNM than previously reported. Titer of anti-HMGCR antibodies and CK levels were significantly higher in IMNM than in other autoimmune connective tissue diseases. The data support the hypothesis of an antigen-driven response in IMNM, and suggests an activation of autoreactive B-lymphocytes in non-IMNM patients. Highlights: Exanthemas were frequently found in anti-HMGCR positive IMNM. Anti-HMGCR antibody titers and CK levels were significantly higher in IMNM patients than in non-IMNM patients. Non-IMNM patients with anti-HMGCR antibodies mostly suffer from connective tissue diseases. Results suggest an antigen-driven immune response in IMNM and activation of autoreactive B lymphocytes in non-IMNM patients. Increased awareness led to an increasing incidence of anti-HMGCR positive IMNM in recent years.