Combined granulocyte and platelet transfusions: inter-relationship between granulocyte and platelet recoveries in the presence and absence of complicating factors.

191 combined collections of granulocytes (PMN) and platelets (PLT) obtained by discontinuous cytapheresis were given to 23 patients with acute myeloid leukaemia (AML). The circulation in recipients of the concomitantly transfused cells was compared by measuring the % recovery of PMN at 1 h, and of PLT at 1 and 20 h. The recovery of both cells was greatly reduced in transfusions accompanied by a transfusion reaction. Fever in recipients had no effect on the recovery of either cell, but PMN recovery was significantly higher in patients receiving oral prednisolone. Alloimmunization to PLT, defined as recovery levels less than 15% at 1 h and/or less than 10% at 20 h, was recorded in 42 transfusions, and PMN recovery was significantly reduced in this group. In transfusions where PMN recovery was 'low' (less than 5%); the recovery of the coincidentally transfused PLT was significantly reduced only in transfusions accompanied by a reaction. These results emphasize the deleterious effects of transfusion reactions and suggest that donor PMN frequently circulate less well in recipients alloimmunized to PLT from the same donor.