Clinical studies of SD-Plasma (SDP) have included treatment of patients with both the acute and chronic relapsing (CRTTP) forms of TTP and replacement of coagulation factors in patients with congenital deficiencies. With the infusion of SDP in 6 patients with CRTTP, platelet counts rose, LDH values dropped, hemoglobin levels remained constant, and the patients continued in good health. In an FFP-controlled study in acute TTP, 16 patients were exchanged with SDP and 10 with FFP. There was no difference between the two groups in patient survival; relapse or remission rate; incidence of treatment resistance; or in per patient total volume infused, number of treatments, average volume per treatment, or number of relapses. Finally, 48 coagulation factor-deficient patients received SDP for surgical prophylaxis, active bleeding and routine prophylaxis for Factor XIII deficiency. The expected levels of the deficient factors were achieved, and the treating physicians concluded that there was control of bleeding.