[Blood transfusion and inflammation as of yesterday, today and tomorrow]

Blood transfusion is made possible principally by use of donated homologous components that - in turn - can be perceived as sources of danger by recipients. This may create an innate immune response dominated by inflammation, especially when transfusion is repeated. Residual leukocytes in blood components can source inflammatory lesions but considerably less than used to be prior to systematic, early and stringent - in process - leukoreduction. Every blood component can cause inflammation, though barely in the case of therapeutic plasma (in such a case, this is mainly restricted to allergy). Iron that may be freed by red blood cells but also processing and storage lesions such as the emission of microparticles can reveal themselves as pro-inflammatory. Platelets in platelet components represent the main source of inflammatory and/or allergic hazards in transfusion; this is linked with processing and storage lesions but also with the platelet physiology itself. It is of utmost importance to avoid inflammatory adverse events in patients that are fragile because of their primary condition and/or treatment; this stands for their safety, as inflammation can be extremely severe and even lethal, and also for their comfort; this increases efficacy of transfusion programs while reducing the overall costs.