RHD positive among C/E+ and D-negative blood donors in Tunisia

Area of Science:

• Immunogenetics
• Blood Transfusion Medicine
• Molecular Biology

Background:

• The RhD blood group system is crucial for transfusion compatibility.
• Accurate RhD typing is essential to prevent hemolytic disease of the fetus and newborn and transfusion reactions.
• D-negative individuals with C and/or E antigens present a unique challenge for RhD genotyping.

Purpose of the Study:

• To investigate RhD (RHD) alleles in Tunisian blood donors who are D-negative but C/E-positive.
• To understand the genetic basis of RhD variations in this specific population.
• To inform transfusion strategies and reduce alloimmunization risks.

Main Methods:

• RHD genotyping was performed on 100 D-negative, C/E-positive blood donor samples.
• Initial screening involved testing for RHD exon 10.
• Positive samples underwent further molecular analysis, including real-time quantitative PCR, allele-specific PCR, and nucleotide sequencing.

Main Results:

• 75% of samples lacked the RHD gene.
• 23% carried hybrid RHD-CE-D alleles (e.g., RHD-CE(3-7)-D, RHD-CE(4-7)-D).
• 2% were identified as weak D (1 weak D type 1, 1 weak D type 5).

Conclusions:

• A significant proportion of serologically D-negative, C/E-positive Tunisian blood donors have complex RHD alleles.
• Systematic RHCE phenotyping in all Tunisian transfusion centers is recommended.
• Considering blood from D-negative C/E-positive individuals as D-positive may help reduce anti-D alloimmunization.