[Monitoring and secondary effects of transfusion of labile blood products].

VIRUS RISKS: Since 1991, the medical community has focused what can be termed transfusion phobia on transmissible viral diseases. Such diseases do not however reflect the overall risk of transfusion. The residual virus risk is the risk of not detecting a viral disease in the donor population which is transmissible by blood or blood products. This risk depends on the prevalence of the disease in the donor population, the duration of serological silence period and the sensitivity of the screening tests. Hepatitis B virus is the number one transfusionally transmissible virus (1/30,000 to 1/250,000 blood transfusion units), but the main risk of post-transfusion viral disease is caused by the hepatitic C virus. The residual risk of HIV contamination is in the range of 1/200,000 to 1/2,000,000 transfusion units. There is a possible risk of transmitting non-conventional agents (Creutzfeldt-Jakob) but no estimation can be established to date. OTHER RISKS: Potentially severe post-transfusion complications are not limited to transmissible viral diseases. All transfusions carry the risk of bacterial contamination, endotoxinic shock, circulary overload, and anti-leukocyte alloimmunization. Currently, the most frequent and most severe transfusion risks concern acute intravascular hemolysis subsequent to an ABO error or incompatibility with another antigen system and presence of alloantibodies.