Risk Factors for Allo-immunization in Sickle Cell Disease
Risk Factors for Allo-immunization in Sickle Cell Disease
Sickle cell patients have a high prevalence of alloimmunization. This high rate of
 alloimmunization can be partially explained by the existence of an antigenic difference
 between the predominantly Caucasian donor population and the sickle cell patients of African
 origin. Genetic and environmental risk factors have also been described.

 The main risk factors that have been shown in retrospective or cross-sectional studies are
 some HLA alleles, the age of the patient, the number of leukocyte-depleted erythrocyte
 concentrates (CED) transfused, the number of transfusion episodes, the age of the CEDs, the
 existence of an inflammatory event at the time of transfusion and the presence of
 anti-erythrocyte autoantibodies.There is also evidence of an impaired TH response but the
 underlying immunological mechanism is not fully understood.

 The aim of this study is to study the prevalence and the risk factors for anti-erythrocyte
 alloimmunization in pediatric and adult patients with Sickle Cell Disease (with a SS
 genotype) who are being followed at Queen Fabiola University Children's Hospital (HUDERF) and
 at the CHU Brugmann Hospital. The identification of risk factors would allow the
 investigators to improve, or at least adapt, their transfusion policy to certain clinical or
 immuno-haematological situations.
Inclusion Criteria:

 - Sickle cell disease patients (HbSS genotype) with a history of blood transfusions within
 the CHU Brugmann and the Queen Fabiola University Hospitals.

 Exclusion Criteria:

 - None