Thrombotic thrombocytopenic purpura: Early and late responders

Abstract
Thrombotic thrombocytopenic purpura (TTP) is characterized by micro‐angiopathic hemolytic anemia (MAHA), thrombocytopenia, neurological symptoms, renal involvement, and fever. We describe our experience in 70 serially encountered TTP patients in the last decade who were treated with a standard therapeutic plasma exchange (TPE) protocol. Seventy percent of the patients were females. The median age of the patients was 43 years (range: 8–80). Sixty patients (85.7%) had a complete response to TPE therapy. This represented 91% of 66 who received at least one TPE. Ten patients died, two patients died before and two during the first plasma exchange. The median number of TPEs performed was nine (range: 1–85). Thirty‐five (58%) out of 60 responded to 3–9 TPEs, and 25 (42%) required 10–34 TPEs for the response. The median total plasma volume exchanged was 28 liters (range: 2.7–250 L) and the mean plasma volumes exchanged during each prodcedure was 3.2 (SD ± 1.09 L). The patients were classified into early responders (ER) and late responders (LR). ERs had a mean platelet count of 180 × 109/L by Day 5, mean LDH of 643 IU/L by Day 7, and required median of seven TPEs. LRs had a mean platelet count of 122 × 109/L by Day 5, mean LDH of 885 IU/L by Day 7, and required median of 19 TPEs (P = 0.001). The platelet counts were significantly higher (P = 0.01–0.03) in ERs on Days 1, 3, and 5 as compared to LRs but the LDH did not differ significantly. Seventy‐seven percent of LRs had exacerbation of TTP and 18% had relapse as compared to 7% each in ERs. Thirteen patients were in coma/semicoma at presentation. Out of these, six died, making coma a bad prognostic indicator. Five of the seven survivors in coma had received two single‐plasma volume exchanges on Day 1. In conclusion, 91% of TTP patients had an excellent response to plasma exchange therapy with FFP. Coma/semicoma appears to be a bad prognostic indicator. LRs needed prolonged treatment with a greater number of patients experiencing exacerbation and relapse of TTP as compared to ERs. Am. J. Hematol. 54:102–107, 1997