Polymyositis with pulmonary and renal involvement refractory to combined immunosuppressive therapy treated with rituximab

Polymyositis (PM) is a chronic autoimmune disease characterised by symmetrical and bilateral inflammation of proximal muscles. Course of the disease is diverse with symptoms varying from painless muscle weakness to myalgias and constitutional symptoms, but also affection of pharyngeal and respiratory muscles in severe cases (1). Interstitial lung disease (ILD) is found in 60–70% of patients at the time of diagnosis. Pulmonary complications are a major factor causing mortality and a marker of poor prognosis (2)