1.
Late relapses in patients successfully treated for thrombotic thrombocytopenic purpura. Canadian Apheresis Group
Shumak KH, Rock GA, Nair RC
Annals of Internal Medicine. 1995;122((8):):569-72.
Abstract
OBJECTIVE To determine the incidence and timing of relapses in patients who have recovered from an acute episode of thrombotic thrombocytopenic purpura. DESIGN Clinical follow-up for 3 to 10 years. SETTING General community outpatient study; patients who had relapse were hospitalized. PARTICIPANTS 63 of 72 surviving patients who had participated in a randomized study that compared plasma exchange and plasma infusion as treatments for thrombotic thrombocytopenic purpura and for whom continued clinical follow-up was obtained. OUTCOME MEASURES Recurrence of thrombotic thrombocytopenic purpura as defined by a decrease in platelet count to less than 100 x 10(9)/L and by the onset of microangiopathic hemolytic anemia as identified by erythrocyte fragmentation in a peripheral blood film. RESULTS 37 of the 63 patients have not had recurrence of thrombotic thrombocytopenic purpura and have remained completely well; 6 patients have not had recurrence but have developed other medical problems; 3 patients have not had recurrence but have residual neurologic defects from the original episode; and 17 patients have had one or more recurrences, occurring 7 months to 8 years after the original episode. As determined by Kaplan-Meier analysis, the projected recurrence rate after 10 years in all surviving patients is 36% (95% CI, 23% to 59%). CONCLUSIONS More than one third of patients who survive an acute episode of thrombotic thrombocytopenic purpura will have at least one relapse during the following 10 years.
2.
Comparison of plasma exchange with plasma infusion in the treatment of thrombotic thrombocytopenic purpura. Canadian Apheresis Study Group
Rock GA, Shumak KH, Buskard NA, Blanchette VS, Kelton JG, Nair RC, Spasoff RA
New England Journal of Medicine. 1991;325((6):):393-7.
Abstract
BACKGROUND Thrombotic thrombocytopenic purpura is an uncommon disease with a high mortality rate even with current treatment. The cause of the syndrome and its optimal treatment are unknown. Although both plasma exchange and plasma infusion have been useful treatments, it is not clear which is superior. In this report we describe a prospective randomized trial comparing plasma exchange with plasma infusion for the treatment of thrombotic thrombocytopenic purpura. METHODS One hundred two patients with thrombotic thrombocytopenic purpura were randomly assigned to receive either plasma exchange or plasma infusion with fresh-frozen plasma on seven of the first nine days after entry into the trial. The total volume of plasma received by patients undergoing plasma exchange was three times that received by patients undergoing plasma infusion. All the patients also received aspirin and dipyridamole. The outcomes in the two groups were compared at the end of the first treatment cycle (day 9) and after six months. RESULTS At the end of the first treatment cycle patients receiving plasma exchange had a higher rate of response as defined by an increase in the platelet count (24 of 51 patients) than those who received plasma infusion (13 of 51, P = 0.025). Of the 51 patients treated with plasma exchange, 2 died, whereas 8 of the 51 patients who received plasma infusion died (P = 0.035). After six months the outcome in the plasma-exchange group was still superior, with a response observed in 40 of 51 patients, whereas 25 of 51 patients in the plasma-infusion group responded (P = 0.002). Eleven patients in the plasma-exchange group died, as did 19 patients in the plasma-infusion group (P = 0.036). The overall mortality was 29 percent. CONCLUSIONS Plasma exchange is more effective than plasma infusion in the treatment of thrombotic thrombocytopenic purpura.