Sécurité immunologique des transfusions

An overview of red blood cell and platelet alloimmunisation in transfusion

Post-transfusion alloimmunisation is the main complication of all those observed after one or more transfusion episodes. Alloimmunisation is observed after the transfusion of red blood cell concentrates but also of platelet concentrates. Besides alloimmunisation due to antigens carried almost exclusively by red blood cells such as those of the Rhesus-Kell system, alloimmunisation often raises against HLA antigens; the main responsibility for that, apart from platelet transfusions, lies with residual leukocytes in the products transfused, hence the central importance of effective leukoreduction right from the blood product preparation stage. Alloimmunization is not restricted to transfusion, but it is also observed during pregnancies, carrying out microtransfusions of blood from the fetus immunizing the mother through the placenta (in a retrograde way). Preexisting maternal-fetal immunization can complicate a transfusion program and intensify the creation of alloantibodies in several blood and tissue group systems. The occurrence of autoantibodies, created by several pathogenic reasons, can also interfere with the propensity of certain recipients of blood components to produce alloantibodies. The genetic condition of individuals is in fact strongly linked to the ability or not to recognize antigenic variants foreign to their own biological program and mount an alloimmune response. Some hemoglobin diseases, in carriers of which transfusions can be iterative and lifelong, are complicated by frequent alloimmunizations and amplification of the complications of these alloimmunizations, imposing even stricter transfusion rules. This review details the mechanisms favoring the occurrence of alloimmunization and the immunological principles for the production of molecular and cellular tools for alloimmunization. It concludes with the main preventive measures available to limit the occurrence of these frequent complications of varying severity but sometimes severe.

[Ethical issues in transfusion medicine]

Ethics is on the cross road of off values that are present along the ways of transfusion medicine. This is an important tool to afford opinions as well as debates that always emerge when discussing transfusion medicine. The wording is particularly important; this was one among several others that characterized the soul of Jean-Jacques Lefrère when he opened the doors of the ethical issues of transfusion medicine.

[Voluntariness and blood donation: Proceedings of an ethics seminar held at the National Institute for Blood Transfusion]

Voluntariness stands for one of the four pillars of ethics in blood donation; it is, however, more related to tradition than to legislation. Because it seems necessary to apply "marketing" techniques to blood collection in order to meet the needs in blood components, both in terms of quantity and quality, one wonders if this may be at the expense of this principle of voluntariness. This seminar-belonging actually to a series of seminars in Ethics in Transfusion Medicine-aimed at questioning the possible weakness of voluntariness in the field of blood donation. To achieve this goal, specialists of numerous disciplines in medical sciences, law and humanities gathered to discuss all related issues to voluntariness in blood donation.