Variant RHD Types in Brazilians With Discrepancies in RhD Typing

Area of Science:

• Hematology
• Immunology
• Genetics

Background:

• Anti-D alloimmunization risk exists in individuals with variant RHD alleles.
• Serologic typing of RhD discrepancies can be challenging.
• Molecular analysis is essential for accurate D variant identification.

Purpose of the Study:

• To investigate D variants in patients and blood donors with typing discrepancies.
• To compare serologic and molecular methods for D variant detection.
• To determine the prevalence of weak D and partial D variants.

Main Methods:

• Analysis of 223 subjects (129 patients, 94 donors) with D typing discrepancies.
• Serologic evaluation using tube and gel hemagglutination with four anti-D reagents.
• Molecular analysis including PCR-SSP, multiplex PCR, RHD BeadChip, and sequencing.

Main Results:

• 168/223 (75%) weak D and 55/223 (25%) partial D variants were identified.
• Serologic results varied significantly based on methods and anti-D reagents.
• Weak D types 1-3 were most common; DAR and DVI were most prevalent partial D variants.

Conclusions:

• Molecular methods are necessary to resolve serologic D typing discrepancies and differentiate weak D from partial D.
• Understanding the distribution of D variants is critical for managing RhD-negative patients and pregnant women.
• Accurate D variant identification aids in preventing anti-D alloimmunization.