[Transfusion risks and alternatives to transfusion]

The emergence of the acquired immunodeficiency syndrome (AIDS) has fueled concerns of both physicians and their patients about safety of blood transfusions. Although AIDS has generated the most fear, the risk today is extremely remote (1/60.000 units of blood). The risk of transmitting infectious disease by homologous transfusion is decreasing, as more donor screening and testing measures are implemented. The blood supply is safer that at any time, but small transfusion risks exist. The most common problems associated with transfusions are temporary: one in 100-300 recipients will experience fever or rash. The biggest problem is a mismatch of the well-known ABO blood groups and once in every 100-400.000 transfusions the hemolytic reaction is fatal. Viral hepatitis is another serious and important risk. At present hepatitis seems to strike between 1 and 3 percent of transfusion recipients. Most, if not all, of transfusion-associated hepatitis cases are caused by hepatitis C virus. Cytomegalovirus can cause primary infection, reactivation or reinfection by transfusion. Immunosuppressed patients are more likely to develop more severe disease. Epstein-Barr virus does not seem to cause significant post-transfusion disease. Bacterial or protozoal infections are an infrequently encountered adverse effect of transfusion. However, some clinical cases document the potential hazard of blood components as a vector for bacteria or protozoa. Homologous blood transfusion down-regulates some immune functions. Host defences against malignancy and infection may in some instances be severely compromised by transfusions of homologous blood.(ABSTRACT TRUNCATED AT 250 WORDS)