Autoimmune Thrombocytopenia (AITP) is a disorder of low blood platelet counts in which platelet destruction is caused by antiplatelet autoantibodies. A large proportion of patients with chronic AITP are refractory to standard therapies including corticosteroids, immune globulin and splenectomy. Cyclophosphamide is a cytotoxic immunosuppressive agent which may induce durable remissions of refractory autoimmune diseases. High-dose cyclophosphamide with peripheral blood stem cell (PBPC) rescue has been proposed as a potential definitive therapy for AITP; however, the infusion of autoreactive lymphocytes could result in relapse. The use of PBPC depleted of T-lymphocytes could circumvent this limitation.