Juvenile dermatomyositis (JDMS) is an autoimmune inflammatory myopathy which primarily manifests with skin, muscle, and blood vessel involvement. Dystrophic calcification or calcinosis has been associated with aggressive disease and/or chronicity. It is usually difficult to control and may be associated with poor wound healing, risk for secondary skin/subcutaneous infection, and adverse quality of life due to pain, joint contractures, and altered mobility. Currently, there is no standard of care for JDMS associated calcinosis. There are limited case reports and clinical trials in JDMS on the use of abatacept, a fully human soluble fusion protein that prevents the costimulatory signaling required in T-cell activation. We describe our center’s experience in the use of abatacept in the treatment of JDMS associated calcinosis.

Methods:

A retrospective chart review of JDMS patients with calcinosis treated with abatacept at our center was performed after IRB approval. Collected data include patient demographics, clinical presentation and course, and therapy. Onset, clinical characteristics, and course of calcinosis following therapy with abatacept were described.

Results:

Four patients were included (females: 3, Hispanic ethnicity: 2). Median age at diagnosis was 4 years. Three patients had disease duration of 1 to 5 months prior to diagnosis, while one patient was diagnosed 48 months following disease onset. All patients had severe disease on presentation, and all received both IV and PO glucocorticoids, IVIG, methotrexate, and hydroxychloroquine. Two patients received rituximab. Median onset of calcinosis from disease onset was 18.5 months. All patients had a combination of superficial, interfascial, interarticular, and tumorous calcinosis. The median time for abatacept use following clinical diagnosis of calcinosis was 13.5 months (range: 5-25). Median duration of follow-up while on abatacept therapy was 13.5 months (range: 10-32). Clinical and imaging improvement of calcinosis were noted within 6-12 months of abatacept initiation. All patients had resolution of pain, tenderness, and inflammatory changes at the sites of calcinosis. Joint contractures related to calcinosis in two patients resolved within 3-5 months of abatacept use. Ulcer formation in one patient resolved. Secondary skin/subcutaneous infection was not observed in all patients despite use of combination immunosuppressive/immunomodulatory therapies. All patients remained free of disease flare throughout therapy.

Conclusion:

We described the clinical course and response to abatacept as adjunct therapy for calcinosis in four patients with juvenile dermatomyositis in this single-center retrospective review. Our patient outcomes suggest that abatacept may be an efficacious and safe treatment option in JDMS associated calcinosis. Further study in larger patient cohorts is warranted.