Prolonged Granulocytopenia from Incompatible Platelet Transfusions

A prolonged decrease in circulating granulocytes accompanied transfusions of HL-A-incompatible platelet concentrates in two afebrile patients with aplastic anemia. The median granulocyte count measured at 20 hours after incompatible platelet concentrates was reduced by 30.8 per cent and remained depressed below pretransfusion levels for as long as four days (median of two days). HL-A-matched platelet concentrates obtained either from siblings or from nonfamily donors did not cause granulocytopenia. The rebound granulocytosis that usually follows transfusion reactions was not observed in these patients presumably because of severely comprised bone-marrow reserves. The prolonged delay in recovery of circulating granulocytes caused by incompatible platelet concentrates may lower host defenses and thus increase the risk of infection. (N Engl J Med 290:1220–1223, 1974)