[Risks and side effects of blood transfusion].

While transfusion of blood components is usually safe, there are risks of adverse effects that can have immunologic, nonimmunologic, or infectious causes. In patients, the fear of infectious disease transmission predominates, although the risk has been extremely low since the introduction of reliable serologic and molecular biological testing methods. This article addresses the incidence, clinical picture, and etiology of adverse effects of transfusion. It also reports on current knowledge concerning transfusion-associated acute lung injury, which has gained much attention in the last few years. Besides hepatitis and human immunodeficiency viruses, cytomegalovirus, parvovirus B19, prion transmission, and the risk of variant Creutzfeld-Jakob disease are also discussed.