Clinical outcomes after platelet transfusions in patients with thrombotic thrombocytopenic purpura.
BACKGROUND
Reports of deterioration and death after platelet (PLT) transfusions in patients with thrombotic thrombocytopenic purpura (TTP) have led to recommendations that they should not be given except for life-threatening hemorrhage.


METHODS
Published reports of PLT transfusions in patients with TTP were systematically reviewed and data from the Oklahoma TTP-HUS Registry, an inception cohort of 382 consecutive patients, 1989 through 2007, were analyzed.


RESULTS
A systematic review identified 34 publications describing outcomes of patients with TTP after PLT transfusions: 9 articles attributed complications to PLT transfusions, 4 suggested that they may be safe, and 21 articles did not comment about a relation between PLT transfusions and outcomes. Fifty-four consecutive patients from the Oklahoma TTP-HUS Registry were prospectively analyzed. ADAMTS13 activity was less than 10 percent in 47 patients; also included were 7 patients whose activity was not measured but who may have been deficient. Thirty-three (61%) patients received PLT transfusions. The frequency of death was not different between the two groups (p = 0.971): 8 (24%) patients who received PLT transfusions died (thrombosis, 5; hemorrhage, 1; sepsis, 2) and 5 (24%) patients who did not receive PLT transfusions died (thrombosis, 4; hemorrhage, 1). The frequency of severe neurologic events was also not different (p = 0.190): 17 (52%) patients who received PLT transfusions (in 5 of these 17 patients, neurologic events only occurred before PLT transfusions) and 7 (33%) patients who did not receive PLT transfusions.


CONCLUSIONS
Evidence for harm from PLT transfusions in patients with TTP is uncertain.
Swisher
Karen K
KK
Hematology-Oncology Section, Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
Terrell
Deirdra R
DR
Vesely
Sara K
SK
Kremer Hovinga
Johanna A
JA
Lämmle
Bernhard
B
George
James N
JN
D051722:ADAM Proteins / Q000172:deficiency; D000071120:ADAMTS13 Protein; D002423:Cause of Death; D006801:Humans; D009422:Nervous System Diseases / Q000209:etiology; D017713:Platelet Transfusion / Q000009:adverse effects* / Q000401:mortality / Q000706:statistics & numerical data; D011697:Purpura, Thrombotic Thrombocytopenic / Q000628:therapy*; D012042:Registries; D015996:Survival Rate; D016896:Treatment Outcome
D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human