Alloanti‐c in a c‐positive, JAL‐positive patient

Abstract

Background and Objectives-In the Rh blood group system, partial D, C, and e antigens are well-known, but a partial c antigen resulting in the production of alloanti-c in a c+ individual is rare. One example of an alloanti-c in a c+ person was an anti-Rh26, which can appear as anti-c, and another was an alloanti-c in a c+ person with a presumed R 1 r phenotype. The finding of an apparent alloanti-c in a transfused c+ patient initiated this investigation.

RHCE*ceCF encodes partial c and partial e but not CELO, an antigen antithetical to Crawford

“…RBCs with altered Rhce and considered to be hr S − included ceAR, ceBI, ceEK, and ceMO, and those considered to be hr B − included ce S (encoded by RHCE * ce 48C, 733G, 1006T ), ceMO, 1,12 and (C)ce S (r′ S ) 1 . Partial c antigens have been reported to be associated with RH:−26, (C)ce S , ce S (340), and ceAR 13‐20 . We have shown here that RhceCF expresses partial c and e antigens.…”

RHCE alleles detected after weak and/or discrepant results in automated Rh blood grouping of blood donors in Northern Germany

“…Even RHcE(M167K), which is obviously relatively frequent in our population (and detected in automated typing with the PK7200 by the absence of reactivity with one of the anti-E used by us), was not referred to our laboratory, probably because it is correctly detected in tube and column techniques. Antibody production by carriers of variant alleles has been described 13,41 and may be problematic in populations, where variant alleles are predominant, 3 but such event is a rarity in Germany. Likewise, alloimmunization against rare antigens expressed by variant alleles is rarely problematic, at least if a crossmatch is performed to detect strong antibodies.…”

RhCE protein variants in Southwestern Germany detected by serologic routine testing

“…The three RhD variants are weak D Type 17 (114W), weak D Type 47 (114G), and weak D Type 25 (114Q) with weakened D antigen expression. Both 114W and 114Q substitutions are known to be associated with JAL antigen expression, 30-32 which has been documented so far in RhCE only. The L115R substitution introduces a basic residue into the putatively hydrophobic transmembraneous segment and the L115P substitution introduces proline, which is known to disturb the regular helix structure.…”

“…Examples of variant RhCE proteins are known that express low-prevalence antigens of appreciable immunogenicity. C w , 4 C x , 4 E w , 14 JAHK, 19 Crawford, 16 and JAL 30-32 antigens are all caused by single-amino-acid substitutions in the RhCE protein. For example, the S122L substitution (365C>T) in the Ce haplotype encodes the JAHK antigen and is associated with a suppression of the C and e antigens.…”