Prevention of primary transfusion-associated cytomegalovirus infection in bone marrow transplant recipients by the removal of white cells from blood components with high-affinity filters.

A prospective study was carried out to determine whether use of cytomegalovirus (CMV) unscreened red blood cells and platelet concentrates, white blood cell (WBC) depleted with high-efficiency filters, would prevent transfusion-associated (TA) CMV infection in CMV seronegative bone marrow transplant recipients. Blood components were filtered in the bloodcentre under quality control and after filtration residual WBC counts were always below 5 x 10(6) cells/U. Since 1990, 23 consecutive allogeneic and 37 autologous CMV seronegative marrow transplant recipients, have been transfused with filtered blood components and followed for 6 months for evidence of CMV infection by monitoring culture and CMV serology. None of the patients showed clinical symptoms of CMV infection, and CMV cultures during episodes of fever were always negative. IgM anti-CMV antibodies were negative during the study in all patients. Low titres of IgG anti-CMV antibodies (5-12 relative ELISA units) were found in 24/60 patients during the first month after bone marrow transplantation (BMT), probably due to passive transfer of IgG administered with the platelet transfusions. 3 and 6 months after BMT, 56 and 48 patients respectively were still alive; and CMV serology was negative in all patients. The results show that TA-CMV infection is preventable by filtration of blood through high-efficiency filters in patients undergoing autologous and allogeneic BMT.