Rh discrepancies caused by variable reactivity of partial and weak D types with different serologic techniques

Area of Science:

• Transfusion Medicine
• Immunogenetics
• Serology

Background:

• RhD discrepancies between historical and current blood typing results pose significant challenges.
• Investigating 10 such discrepancies was the focus of this study.

Purpose of the Study:

• To investigate RhD discrepancies and evaluate methods for resolving them.
• To assess the performance of monoclonal anti-D reagents and FDA-approved reagents in identifying weak and partial D variants.

Main Methods:

• Automated gel technology and FDA-approved reagents were used for initial screening.
• Monoclonal anti-D panels, multiplex RHD exon polymerase chain reaction (PCR), weak D PCR-restriction fragment length polymorphism, and RHD exon 5 and 7 sequencing were employed.

Main Results:

• Two samples identified as DVa possessed the DAR allele.
• Weak D Type 1 and Weak D Type 2 samples exhibited variable reactivity with monoclonal and FDA-approved anti-D reagents.
• D epitope profiles differed among Weak D Type 2 samples.

Conclusions:

• Monoclonal anti-D reagents failed to differentiate between partial D and Weak D Types 1 and 2.
• Weak D Types 1 and 2 demonstrate inconsistent reactivity with current FDA-approved reagents and technologies.
• Molecular testing is crucial for accurately identifying partial and weak D variants to resolve discrepancies and guide transfusion decisions, thereby preventing RhD alloimmunization.