Use of rituximab in histologically confirmed idiopathic inflammatory myositis: a case series.

The purpose of the study was to undertake an audit of the use of rituximab in refractory idiopathic inflammatory myositis (IIM). Patients with biopsy-proven refractory IIM treated with rituximab, attending the rheumatology clinic at the Royal Adelaide Hospital were identified by searching the electronic database of patient records from 2007 to March 2013. Seven cases (five women, two men), age range 31 to 68 years with histologically confirmed IIM, were identified. All patients had received rituximab following other immunosuppressive agents, including prednisolone. With rituximab, all patients showed improvement in muscle strength and reduction in muscle enzyme levels and required reduced doses of oral corticosteroids. Response continued for at least 5 months from the initial treatment. No serious adverse events were noted, and there were no infections during the study period. This case series supports the use of B cell depletion therapy with rituximab as an effective treatment for patients with refractory IIM.