Subcutaneous immunoglobulin in polymyositis and dermatomyositis: a novel application

To describe the feasibility and safety of subcutaneous immunoglobulin (SCIg) in polymyositis (PM) and dermatomyositis (DM).

Since 2009, we used SCIg to treat patients with severe idiopathic myositis (4 with DM, 3 with PM), diagnosed according to the Bohan and Peter's criteria. SCIg (Vivaglobin®; CSL Behring) was administered by a programmable pump at the patient's usual IVIg monthly dose fractioned into equal doses given subcutaneously at weekly intervals. A standardized protocol was used to evaluate patients and to assess disease activity, treatment response and quality of life.

Seven female patients were studied. All were Caucasians, with a median age of 53 years and a median disease duration of 72 months. The median follow-up period was 14±4 months. During treatment period, no relapse of the disease occurred. All patients showed a favourable clinical response and reported a good tolerance to the treatment with an improved quality of life. CK serum levels decreased over time with a concomitant improvement in MRC and Rankin modified scores. Three patients were able to discontinue the immunosuppressant and all to reduce the daily maintenance prednisone dose.

Our experience demonstrates the beneficial effect and the safety of SCIg administration in active and refractory inflammatory myopathies.