Anti-RHCEDce monoclonal antibody, clone BRIC69

Objectives Anti-Rhc antibodies may be the reason for the hemolytic disease of the newborn, therefore, noninvasive Rhc determination is important for pregnancy monitoring. For this purpose, we decided to introduce real-time polymerase chain reaction (PCR) method. Methods Blood from 200 donors, plasma and whole-blood from 11 Rhc-negative mothers, as well as blood from fathers and newborns were examined. Rhc sensitivity and specificity were first determined by real-time PCR using genomic DNA from donors. The same Rhc genotyping method was used for fetal Rhc detection in maternal plasma. To confirm the fetal Rhc-negative result, plasma was tested with a panel of bialletic insertion/deletion polymorphisms for the presence of fetal DNA. Results The c allele assay showed full specificity. The mean Ct value for one copy of c allele diluted in C-negative DNA was determined from extrapolating the correlation curve as 39.9. Full concordance was observed between the fetal Rhc genotypes from maternal plasma and the newborn phenotypes. Conclusions Preliminary results show that it is possible to examine fetal c allele of RHCE gene in the plasma of pregnant women with anti-c by means of a noninvasive method. The diagnostic accuracy of the procedure, however, has yet to be confirmed in a larger group. Copyright (C) 2008 John Wiley & Sons, Ltd.

Introduction: Patients with RH variants presenting antibodies directed to RH high frequency antigens or multiple RH antibodies might, in some occasions, be better served with RH genotype-matched units, requiring screening for RH variants among blood donors. To date, strategies to identify donors with RH variants were restricted to selecting individuals of African descent based on self-reported race, what can be inaccurate in racially mixed population. Our goal was to: 1) Screen for donors with RH variants in a mixed population using self-declared race and Rh phenotype as selection criteria; and 2) Verify if including the Duffy null genotype in the screening algorithm increases its effectiveness. Methods: Brazilian donors were included if self-declared as black and phenotyped as R0r or R1r. All individuals were genotyped for RHCE exons 1, 5, 6 and 7 and for the FY*B c.-67 T > C polymorphism in order to determine the Duffy null genotype. RHD variants were searched for in cases of altered RHCE. Results: Among 2500 blood donors, 217 fulfilled the inclusion criteria and were enrolled. Fifty-three (24.4 %) had a predicted clinically relevant Rh phenotype (partial antigens or lack of high frequency antigens). Twelve donors (5.5 %) had a predicted RhCE phenotype lacking either hrB or hrS. Most cases with predicted lack of high frequency antigens (66.7 %) occurred in donors with the Duffy null genotype. Conclusion: Selecting donors based on self-declared race, Rh phenotype and Duffy null genotype is feasible and effective in identifying RH variants lacking Rh high frequency antigens among racially mixed donors.