Frequency and characterization of RHD variants in serologically D– Surinamese pregnant women and D– newborns

BACKGROUND: Numerous RHD variant genes affect the expression of D on the red blood cell surface. In Suriname, 4.3% of pregnant women were D–, ranging from virtually zero to 7% among ethnic groups. Characterization of RHD variants, which are associated with a variable potential to induce anti-D, is of practical clinical importance especially in case of limited access to preventive measures. Here we report on the occurrence of RHD variant genes in Surinamese serologically D– pregnant women and their D– newborns from different ethnic groups. STUDY DESIGN AND METHODS: The RheSuN study is a cross-sectional cohort study in D– pregnant women and their newborns, who visited hospitals in Paramaribo, Suriname, during routine pregnancy care. The presence of RHD variants was investigated using quantitative polymerase chain reaction targeting RHD Exons 5 and 7 and RH-multiplex ligation–dependent probe amplification. RESULTS: Seven RHD variant genes were detected in 35 of 84 women and four RHD variant genes in 15 of 36 newborns. The RHD*03 N.01 and RHD*08 N.01 variants represented 87% of a total of 62 variant genes. Variants were comparably frequent among ethnicities. In four cases genotyping would have changed anti-D prophylaxis policy: one woman with a RHD*01EL.01 variant, not associated with anti-D formation and three D– newborns with RHD*09.01 and RHD*09.03.01 variants, potentially capable of inducing anti-D. CONCLUSION: RHD variants at risk for anti-D are common among serologic D– individuals from African descent in Suriname. While genotyping D– women has limited added value, it may be considered in newborns from D– women.