Six years' experience performing RHD genotyping to confirm D- red blood cell units in Germany for preventing anti-D immunizations

Transfusion. 2009 Mar;49(3):465-71. doi: 10.1111/j.1537-2995.2008.01975.x.


Background: Red blood cell (RBC) units of D+ donors are falsely labeled D- if regular serologic typing fails to detect low D antigen expression or chimerism. The limitations of serology can be overcome by molecular typing.

Study design and methods: In January 2002, we introduced a polymerase chain reaction (PCR)-based assay for RHD as a routine test for first-time donors who typed D- by serologic methods including the indirect antiglobulin test. Samples were tested in pools of 20 for the RHD-specific polymorphism in Intron 4. RHD alleles were identified by PCR and nucleotide sequencing.

Results: Within 6 years, 46,133 serologically D- first-time donors were screened for the RHD gene. The prevalence of RHD gene carriers detected by this method was 0.21 percent. Twenty-three RHD alleles were found of which 15 were new. Approximately one-half of the RHD gene carriers harbored alleles expressing a DEL phenotype resulting in a prevalence of 0.1 percent.

Conclusion: The integration of RHD genotyping into the routine screening program was practical. We report 6 years' experience of this donor testing policy, which is not performed in most transfusion services worldwide. RBC units of donors with DEL phenotype have been reported to anti-D immunize D- recipients. We transferred those donors to the D+ donor pool with the rationale of preventing anti-D immunizations, especially dreaded in pregnancies. For each population, it will be necessary to adapt the RHD genotyping strategy to the spectrum of prevalent alleles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Base Sequence
  • Blood Donors
  • Codon
  • DNA, Complementary / genetics
  • Erythrocytes / immunology*
  • Erythrocytes / metabolism*
  • Exons / genetics
  • Genotype
  • Germany
  • Humans
  • Immunization*
  • Isoantibodies / immunology*
  • Phenotype
  • Rh-Hr Blood-Group System / genetics*
  • Rh-Hr Blood-Group System / immunology*
  • Rho(D) Immune Globulin
  • Time Factors


  • Codon
  • DNA, Complementary
  • Isoantibodies
  • RHO(D) antibody
  • Rh-Hr Blood-Group System
  • Rho(D) Immune Globulin
  • Rho(D) antigen