Sucessful Outcome in Poor-Prognosis Acute Thrombotic Thrombocitopenic Purpura Treated with Plasma Exchange and Rituximab.

Background: Thrombotic thrombocytopenic purpura (TTP) is a rare and severe disease that must be diagnosed and treated promptly for a successful outcome.

Case Report: In February 2005, a 44-year-old woman was admitted with severe microangiopathic hemolytic anaemia, jaundice, fever, seizures followed by coma and hypovolemic shock. She had joint pain 20 days before admission (anti-nuclear factor positive; 1/160) and had short-term episodes of bizarre behavior 1 week before admission. Her LDH was 2,860 IU/L; platelet count 37,000/mm³; hemoglobin 5.1 g/dl; blood smears contained schistocytes; AST 240 U/L; ALT 166 U/L; HIV and hepatitis seronegative, and CT normal at admission. TTP was diagnosed and pulse methylprednisolene initiated (1 g iv for 3 days) with single-volume daily plasma exchange using fresh frozen plasma. After two sessions, there was marginal neurological improvement, platelet count increased to 95,000/mm³ and LDH decreased to 2,199 IU/L. After six plasma exchanges, neurological status worsened, LDH increased sharply (7,139 IU/L) as did ALT (1,700 U/L), AST (3,000 U/L) and platelet count was 72,000/mm³. Rituximab (four, weekly 375 mg/m² doses) and plasma exchange with cryosupernatant substitution fluid were initiated. The first plasma exchange was postponed until 24 hours after the first dose of rituximab and 48 hours after subsequent doses. Within two days, there was neurological improvement, stable platelet levels and decreased LDH. Complete remission was achieved after 23 plasma exchanges and four doses of Rituximab. Plasma exchange was tapered and the patient remained in sustained remission until now. There were episodes of hives related to plasma exchange, but no toxicity related to rituximab.

Conclusion: Plasma exchange with cryosupernatant substitution fluid and rituximab had an important role in the successful treatment of this patient - a systematic clinical trial setting should be considered in order to confirm these findings.