[The present status of blood filtration--fundamentals and the clinical significance of leukocyte depletion and microaggregate filters in blood transfusion].

In this review the role of the latest generation of leukodepletion blood filters and the adverse reaction of leukocytes i.e. alloimmunisation, immunosuppression, nonhaemolytic febrile transfusion reaction, platelet refractoriness, transmission of infectious agents are described and discussed. Leukocyte-poor blood component is indicated for patients with a history of nonhaemolytic febrile transfusion reaction, in avoiding alloimmunisation in patients waiting for transplantation or platelet refractoriness and in preventing CMV-infection. In the review the role of microaggregate filters in transfusion complications, namely, nonhaemolytic febrile transfusion reaction, thrombocytopenia, adult respiratory distress syndrome (ARDS), fibronectin depletion and histamine release is evaluated. The need of microfiltration of autologous blood is discussed. It appears that the use of 40 microns microfilters is warranted in a broad array of intensive care settings.