Study of 206 transfused sickle cell disease patients: immunization, transfusion safety and red blood cell supply

Prevention of hemolytic transfusion reactions depends upon our capacity to prevent allo-immunization and conflicts between antigens of transfused red blood cells and antibodies produced by the recipient. In this study, we show that to secure transfusion of sickle cell disease patients, it is necessary to take into account their immunohematologic characteristics in the organization of transfusion. Immunohematological data of 206 chronically transfused patients have been collected as well as phenotypes of transfused units. In order to prevent allo-immunization against C and E antigens for patients typed D+C-E-c+e+ (56%), 26% of the transfused units were D-C-E-c+e+. We found that 47% of the patients had a history of allo-immunization, whereas only 15% produced an antibody the day of inclusion in the study. The non-detectable antibodies were frequently known as dangerous for transfusion. Finally, this study shows the frequency of anti-D in D+ patients and anti-C in C+ patients, pointing out the question of partial antigens. To insure optimal transfusion safety for sickle cell disease patients, three points have to be improved: blood donation within the Afro-Caribbean community living in France, access to history of immuno-hematological data, detection of variant antigens, especially within the RH blood system.