RHD variants in Polish blood donors routinely typed as D–

Abstract

BACKGROUND Blood donors exhibiting a weak D or DEL phenotypical expression may be mistyped D negative by standard serology hence permitting incompatible transfusion to D negative recipients. Molecular methods may overcome these technical limits. Our aim was to estimate the frequency of RHD alleles among the apparently D negative Polish donor population and to characterize its molecular background. STUDY DESIGN AND METHODS Plasma pools collected from 31,200 consecutive Polish donors typed as D negative were tested by real-time PCR for the presence of RHD specific markers located in the intron 4, exons 7 and 10. RHD positive individuals were characterized by PCR or cDNA sequencing and serology. RESULTS Plasma cross-pool strategy revealed 63 RHD positive donors harboring RHD*01N.03(n=17), RHD*15(n=12), RHD*11(n=7), RHD*DEL8(n=3), RHD*01W.2(n=3), RHD-CE(10)(n=3), RHD*01W.3, RHD*01W.9, RHD*01N.05, RHD*01N.07, RHD*01N.23, RHD(IVS1-29G>C) and two novel alleles: RHD*(767C>G)(n=3), RHD*(1029C>A). Among 47 cases available for serology, 27 were shown to express the D antigen CONCLUSION 1/ Plasma cross-pool strategy is a reliable and cost-effective tool for RHD screening. 2/ 0.2% of D negative Polish donors carry some fragments of the RHD gene; all of them were C or E positive. 3/ Almost 60% of the detected RHD alleles may be potentially immunogenic when transfused to a D negative recipient.

RHD-Positive Alleles among D- C/E+ Individuals from India

“…Indeed investigating the origin of exons 2 and 8, which share common sequences in both RHD and RHCE [28], may yield different results as location of PCR primers in intronic regions varies depending on the original locus, while exonic sequences are the same. To our knowledge this allele has been reported in Caucasians only to date [7,9,16]. In 6 individuals, RHD-CE(4-9)-D allele was identified (table 1: Ccee, 5; ccEe, 1).…”

“…Although the main RHD alleles resulting in a D- phenotype, i.e. RHDΨ and (C)ce s , are most frequently cis -associated with RHCE*ce , other RHD gene variants in D- individuals, including several hybrid genes, have been shown to segregate with RHCE alleles expressing C and/or E (C/E+) antigens in Caucasian, Asian, African, and mixed populations [4,7,8,9,10,11,12,13,14,15,16,17,18,19,20]. …”

Frequency and characterization of known and novel RHD variant alleles in 37 782 Dutch D‐negative pregnant women

“…Interestingly, the RHD*721A>C allele was detected in seven cases whereas all other novel alleles, except the RHD*1074‐1G>A allele, were detected in single cases. This allele was not detected in previous studies performed in Germany, Austria, Poland and Belgium, respectively (Flegel et al , ; Polin et al , ; Orzinska et al , ; Van Sandt et al , , respectively, indicating that this allele is specific for the Dutch population. All women positive for the RHD*721A>C allele had Dutch surnames but we have no indication that these women are related.…”

“…Three large studies have been performed (46 133 Ddonors in Germany (Flegel et al, 2009), 31 200 D-donors in Poland (Orzinska et al, 2013) and 23 330 D-donors Austria (Polin et al, 2009)) to ascertain the presence of RHD variant alleles in D-donors, in which considerably lower percentages of D-donors carried RHD variant alleles, 0Á21%, 0Á20% and 0Á40%, respectively. The African RHD*Ψ allele was observed at low frequency (0Á03%) in the German donor population (Flegel et al, 2009) and not among the Austrian and Polish donors (Polin et al, 2009;Orzinska et al, 2013). Furthermore, in our study the RHD*06 variant was tested as D-on purpose, while this was not the case in other studies.…”

14 Years of Polish Experience in Non-Invasive Prenatal Blood Group Diagnosis

“…Since 2000, fetal RHD in the plasma of RhD-negative pregnant women have been analyzed at Warsaw's IHTM (the reference laboratory for pregnant Polish women with detected alloantibodies) using real-time PCR (qrtPCR) [8]. Over the years, we have modified the RHD protocol in subsequent projects to adjust the test to the Polish population of RhD-negative individuals, to cut costs, or to adapt it to new equipment [9,10]. As in many laboratories across Europe, we provide RHD NIPD as a service for RhD-negative mothers with anti-D antibodies.…”