FACTORS ASSOCIATED WITH RESPONSE TO PLATELET TRANSFUSION FOLLOWING HEMATOPOIETIC STEM-CELL TRANSPLANTATION

We studied 526 consecutive post-transplant platelet transfusions to de termine the factors associated with response to platelet transfusion i n the BMT setting. Poor responses to platelet transfusions occurred fr equently, with 310 of the 484 evaluable transfusions (64%) resulting i n post-infusion corrected count increments of less than 7500. Factors associated with poor response to platelet transfusion by both univaria te and multivariate analysis included, (1) presence of serum lymphocyt otoxic antibodies; (2) male sex; (3) body surface area greater than 1. 7 m(2); (4) transfusion of red cells on the day of the platelet infusi on; (5) concurrent administration of steroids; (6) major ABO mismatch between the recipient and the platelet product; and (7) (among women) a history of one or more pregnancies prior to transplant. Paradoxicall y, a history of greater than 25 blood product exposures prior to trans plant, and evidence of prior CMV infection in either the bone marrow d onor or recipient were associated with higher CCIs by both univariate and multivariate analysis. Factors that showed little correlation with response to platelet transfusion included, (1) age of the infused pla telet product; (2) concurrent fever; (3) recent administration of intr avenous immunoglobulin; and (4) absolute neutrophil count at the time of the infusion. The factors associated with response to platelet tran sfusion in BMT patients appear to be different from those observed in the non-transplant setting.