A Case of Autoimmune Myocarditis Treated with IL-17 Inhibition

Myocarditis is defined as inflammation targeting the heart muscle. Autoimmune myocarditis is a subtype of myocarditis that can occur as an isolated entity in which the primary targeted organ is the heart or as part of a systemic autoimmune disease. The pathogenesis of autoimmune myocarditis has been studied using experimental autoimmune myocarditis mouse models. These studies have established the role of TH17 and IL-17 in the development and progression of myocarditis. While IL-17 inhibition has been tested in these mouse models, there are no reported cases of IL-17 inhibitors being utilized in humans to treat autoimmune myocarditis. We report a patient diagnosed with autoimmune myocarditis in the setting of psoriasis treated initially with prednisone and methotrexate without improvement. The patient was then started on an IL-17 inhibitor secukinumab, directly targeting the immune mechanisms found to be responsible for autoimmune myocarditis and its progression as evidenced by the experimental autoimmune myocarditis mouse models. We provide nuclear scan imaging pre- and post-treatment with secukinumab documenting resolution of our patient’s autoimmune myocarditis. This novel case highlighting the success of IL17 inhibition in treating autoimmune myocarditis, a disease with no truly effective treatment and with potentially devastating consequences, provides an exciting avenue for future research in larger patient populations to further assess the efficacy of this treatment modality.