No abstract

Background RH43 (Crawford) is encoded by RHCE*ce with nucleotide changes 48G>C, 697C>G, and 733C>G (RHCE*ceCF). We investigated the Rh antigen expression and antibody specificities in four patients with this allele. Methods Hemagglutination tests, DNA extraction, PCR-RFLP, AS-PCR, reticulocyte RNA isolation, RT-PCR cDNA analyses, cloning, and sequencing were performed by standard procedures. Results RBCs from two patients typed D+C−E−c+e+/−, hrS−/+W, hrB− and their serum was reactive (3+) with all RBC samples of common Rh phenotype tested, but non reactive with Rhnull or D- - RBCs (apparent alloanti-Rh17). At the RHCE locus, Patient 1 was homozygous for RHCE*ceCF, and Patient 2 inherited RHCE*ceCF in trans to a silenced RHCE*cE. Cross testing of serum and RBCs from these two samples showed mutual compatibility, indicating that both antibodies define the same novel high prevalence antigen on Rhce. Two additional patients, one whose serum contained alloanti-c but the RBCs typed C+c+, and one whose serum contained anti-e but the RBCs typed E+e+, also had RHCE*ceCF. RHCE*Ce was present in trans in the former and RHCE*cE in the latter patient. Conclusion We report that amino acid changes on RhceCF (Trp16Cys, Gln233Glu, and Leu245Val) alter the protein to the extent that c and e antigens are partial, and a high prevalence antigen, we have named CELO (provisional ISBT number 004058; RH58) is not expressed. CELO is antithetical to RH43 (Crawford).

We describe two new high-prevalence Kell antigens, KHUL (ISBT 006037; KEL37) and KYOR (ISBT 006038; KEL38), and two novel alleles encoding K0 phenotypes. We caution that antibodies produced by individuals with K0 RBCs or lacking high-prevalence antigens can present as anti-Kp(b) .