the cause of fever after platelet transfusion?

Febrile responses to platelet transfusions are common but some can be life-threatening and the cause of these reactions is largely unknown. In June 23 Lancet, Richard Phipps and colleagues from University of Rochester Cancer Center, Rochester, New York, suggest that these febrile responses could be due to the release of CD40 ligand from the platelets.

Human platelets contain preformed CD40 ligand that can be expelled after activation to initiate the wound healing process. The CD40 ligand is associated with the production of proinflammatory prostaglandin E2 (PGE2), the key inducer of fever in man.

Phipps et al. randomly assessed 9 preparations of platelets due for transfusion and found that the amounts of CD40 ligand (3000 ng/L to more than 7000 ng/L) was similar to concentrations found in human blood during chronic inflammation (Lancet 2001, 357:2023-2024).

They speculate that keeping the release of CD40 ligand to a minimum,...