Molecular blood typing of patients with Sickle Cell disease in Germany

Background

Because of acute and chronic symptoms patients with Sickle Cell Disease (SCD) require frequent blood transfusion. The ethnic background of most SCD patients is African or Arabian, whereas, the ethnicity of most blood donors in Germany is European. Since the prevalence of antigens is significantly different in the populations we aimed to identify SCD patients with high risk for alloimmunization against blood from European donors by molecular boold typing of the most relevant blood group antigens.

Methods

DNA samples from 249 SCD patients were subjected to typing of the genetic markers for the blood group antigens D, C/c, E/e, K/k, M/N, S/s, Fy(a/b)/Fy0 and Jk(a/b) according to international recommendations. Genotyping was performed by using inhouse validated PCR-based methods and a commercial kit for RHD/RHCE (RBC-FluoGene CDE eXtend; inno-train GbmH, Kronberg, Germany). Allele frequencies in the SCD patients were compared with data for the African and European population in the gnomAD database.

Results

As expected, DAU alleles were the most frequent RHD variant alleles in SCD patients and 15 % were homo- or hemizygous for a DAU allele associated with a high risk for alloimmunization against D. The Fy0 allele was frequent in SCD patients (0.79) with 62 % being homozygous as known for Africans. From the genotyping data we could assume that 82 % of the SCD patients were negative for the Fy(b) antigen. The Fy(b) antigen is also negative in 20 % of our blood donors which can be considered for Fy(b)-matched transfusion. In summary, the allele frequencies observed in SCD patients corresponded to the allele frequencies reported for the African population.

Conclusion

For the transfusion of SCD patients without alloantibodies it is recommended to use blood matched for ABO, D, CcEe and K. If patients have clinically relevant alloantibodies the transfused blood should be additionally matched for Fy(a/b), Jk(a/b) and S/s. Based on the genotype data we were able to identfy the SCD patients with a high risk for alloimmunization against blood group antigens such as D, Fy(b) and others.

Offenlegung Interessenkonflikt:

No conflicts of interest