Corticosteroids are often seen as a necessary evil in the treatment of inflammatory diseases. However, what if steroids, along with their side effects, could be avoided in the treatment of inflammatory myopathies? At ACR 2016, Poster #2316, "Successful Treatment of Statin-Induced Autoimmune Myopathywithout Corticosteroids" aimed to address this issue.
Statin-Induced Autoimmune Myopathy (SIAIM) can present with severe muscle weakness, high CK levels, and may be refractory to treatment, including steroids. Because of the severe nature of this disease, early use of therapy such as IVIG has been used as successful induction therapy, or even as monotherapy. The objectives of this retrospective study were to describe a cohort of patients with SIAIM who were not treated with corticosteroids, and to better elucidate their phenotype. Patients in the study had documented presence of the anti-HMGCR autoantibody, which may be associated with SIAIM. Patients were statin exposed and did NOT receive any corticosteroid treatment. Remission was achieved when the serum CK level went below 500 U/L, and maintenance of this remission was described as sustaining this low level for at least 6 months.
Overall, of 45 anti-HMGCR positive patients, 42 were exposed to statins and 8 patients were not treated with steroids. Manifestations of myopathy ranged from stage 1 (serum CK elevated but normal strength and EMG) to stage 3 (CK elevation, proximal muscle weakness, myopathic EMG). Remission was achieved in all patients presenting in stage 1 with methotrexate monotherapy alone, and the mean time to remission was 7 months. In patients with stage 3 myopathy, IVIG was used successfully in patients to induce remission with either methotrexate or methotrexate plus azathioprine. In one patient, this response was achieved with methotrexate-azathioprine combination alone. Mean time to remission in stage 3 was 10 months. None of the patients required steroids to achieve remission.
Perhaps early detection of inflammatory myopathies, with DMARD treatment as soon as possible, may minimize the use of steroid therapy and lead to achievement of remission without steroid side effects and complications? I will always start a DMARD at the same time as steroids, but this study is interesting in that it suggests skipping steroids altogether.
How would you feel about this strategy and would it change your practice? Would you feel comfortable doing this in mild cases but not severe? Moreover, what is the ideal DMARD treatment? If this is the strategy going forward, more studies looking at ideal initial DMARDs for monotherapy, as well as situations in which to consider IVIG or combination therapy, would be helpful!