title: Identification of two new D variants, DHMi and DHMii using monoclonal anti-D.
abstract: Fifteen examples of red cells are described which showed discrepant reactivity on routine grouping with two monoclonal anti-D typing reagents, HAM-A being negative and MAD-2 strongly positive. The reaction profile of these cells with a number of monoclonal anti-D characterised the samples into two new variant groups, DHMi and DHMii. DHMi was characterised by a negative reaction with BRAD-8 and DHMii by a negative reaction with BRAD-5. DHMi cells were found to have a papain-sensitive site, identified by Mab 21 G6, which was not detectable in DHMii. The presence of allo-anti-D in one case of DHMi suggests a partial D in these individuals. The positive reaction of HAM-A with sialidase- and endo-F-treated DHMii cells suggests that sialic acid and/or N-glycans could possibly be involved in blocking the reaction with untreated cells. All samples typed as C-E+. One was e negative while the rest had variable depression of the e and f antigens. Marginal depression of E was seen with those DHMi cells tested, but not with DHMii cells. Data from family studies suggest that the variant D in both DHMi and DHMii is inherited as a cDE gene complex and is controlled by the RH locus.
authors.affiliation: International Blood Group Reference Laboratory, Bristol, UK.
authors.forename: J
authors.initials: J
authors.lastname: Jones
mesh_terms: D000581:Amidohydrolases; D000911:Antibodies, Monoclonal; D000940:Antigenic Variation / Q000235:genetics*; D005838:Genotype; D006801:Humans; D009439:Neuraminidase; D010375:Pedigree; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D010455:Peptides / Q000302:isolation & purification*; D012204:Rh-Hr Blood-Group System / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D000911:Antibodies, Monoclonal; D010455:Peptides; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen; D009439:Neuraminidase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase