A case of thrombotic thrombocytopenic purpura refractory to plasma exchange

We experienced a case of thrombotic thrombocytopenic purpura (TTP) finally relieved after 74 sessions of plasma exchange (PE). The patient was a 56-year-old male. In August 1999, he was examined in emergency because of brown urine and a lowered level of consciousness. As TTP was suspected according to the laboratory findings of abnormally high lactate dehydrogenase and total bilirubin, decreased platelet counts, and numerous fragmented erythrocytes, he was admitted to the ICU of our hospital. Immediately after admission, PE was started consecutively. Upon concomitant use of antiplatelet drugs and prostacyclin, the level of platelet counts recovered to 100,000/microl once, but decreased again. Thus, in addition to the PE, prednisolone and vincristine were administrated, which elevated the level of platelet counts to 200,000 to 300,000/microl. Since the erythrocyte fragmentation was noted frequently, PE was continued twice a week. From the 60th day of admission onward, however, his body temperature rose above 40 degrees C with a rapid increase of C-reactive protein. A blood culture detected methicillin-resistant Staphylococcus aureus (MRSA) which derived from a left lung abscess. During the course of anti-MRSA treatment, he presented acute renal failure and acute hepatic dysfunction, but survived because of the combined therapy. He was discharged on the 180th day of admission. These results suggest that a combined therapy of steroid and vincristine is effective to treat TTP refractory to PE, but careful attention should be paid to the complications caused by immunosuppression.