Abstract
Abstract
Background
In patients with variant RhD phenotypes, serologic reactions for partial
RHD
genotypes are indistinguishable from other variants.
Study Design and Methods
In two US transfusion services, patients were typed for RhD by automated
microplate RhD typing (Werfen,
Norcross, GA) using two directly agglutinating IgM anti‐D reagents, MS201 (epitope RhD (epD) 6.1) in Series 4 (Anti‐D4) and TH‐28 (epD6.4) in Series 5 (Anti‐D5). For weak or discrepant RhD typing, we performed a
RHD
DNA microarray (RHD BeadChip, Werfen, Norcross, GA). For hemi‐ or homozygous c.697G>A (rs1053359), we obtained c.1136C>T (rs61740966) testing (New York Blood Center) to distinguish DV type 5 (DV.5) from DAU4 (c.1136T). We retrospectively examined previous cases with negative‐weak anti‐D4 and strong anti‐D5 reactions for correlation with either DV.5 or DAU4 genotypes.
Results
Eight of 442 patients with weak or discrepant RhD phenotypes (1.8%) had 0–1+ anti‐D4, 3–4+ anti‐D5 phenotypes. They were the only 8 patients with c.697G>A (correlation
p
Discussion
DV.5 and DAU4 alleles express disruptive p.Glu233Lys and are associated with hemolytic anti‐D.
Microplate RhD typing
with decreased IgM anti‐D4 reactions did not associate DV.5 and DAU4 with alloimmunization but indicated increased risk of anti‐D alloimmunization. Similar epD6.1‐weak, epD6.4‐strong RhD reactions were observed in 10 DV.5 patients using automated microcolumn typing. Development of anti‐D reagents detecting patients with other partial
RHD
genotypes beyond DVI is desirable.