Autologous peripheral blood stem cell transplantation in a patient with severe mixed connective tissue disease

A 65-year old man with mixed connective tissue disease (MCTD) and severe th erapy resistant polymyositis was considered for high-dose cyclophosphamide (200 mg/kg) supported by autologous stem cell transplantation (ASCT). During a 21 months follow-up there has been a significant subjective, but o bjectively only a slight improvement in muscle strength. Initially the leve ls of serum creatine kinase and serum aldolase normalised, but are at 21 mo nths at about the same level as before ASCT. Based on histopathological exa mination there is still active myostitis. Our case would suggests that this treatment may have some efficacy in MCTD with severe polymyositis although longer follow-up is needed.