Effective molecular RHD typing strategy for blood donations

Area of Science:

• Hematology
• Molecular Biology
• Genetics

Background:

• Over 50 weak D and numerous partial D alleles exist, identifiable via molecular methods like PCR and DNA sequencing of the RHD gene.
• A novel real-time RHD typing scheme was developed and evaluated over an 8-month period.

Purpose of the Study:

• To develop and validate a real-time PCR-based RHD typing scheme for accurate identification of weak D alleles.
• To characterize weak D and D- blood samples using molecular methods.

Main Methods:

• Standardized immunohematologic methods were used for 53,347 blood donors and patients.
• 201 weak D samples underwent molecular characterization using real-time PCR and RHD gene sequencing.
• 2,427 D- phenotype samples were tested for RHD markers.

Main Results:

• Molecular typing identified 15 known weak D alleles and one new type (weak D Type 49) among 201 samples.
• Weak D Types 1-3 constituted approximately 60% of identified alleles, with Weak D Type 1 being the most frequent.
• Three D- samples revealed RHD markers, with sequence-based typing identifying two DEL alleles and one weak D Type 4.3.

Conclusions:

• The developed RHD genotyping scheme reliably detects aberrant alleles in weak D red blood cell units.
• Testing D- blood samples as a quality control measure enhances the detection of weak D or DEL phenotypes, overcoming standard serology limitations.