Partial D, weak D types, and novel RHD alleles among 33,864 multiethnic patients: implications for anti-D alloimmunization and prevention

Transfusion. 2005 Oct;45(10):1554-60. doi: 10.1111/j.1537-2995.2005.00586.x.

Abstract

Background: The D antigen includes category D, partial D, and weak D types, which are important because anti-D alloimmunization can occur in some but not all persons that express a variant RHD allele. At present, there is little prospective information on the prevalence of D variants among obstetric patients and potential transfusion recipients.

Study design and methods: The RHD alleles were prospectively examined in a large patient population identified on the basis of a difference in anti-D reactivity between two reagents.

Results: Fifty-five discrepancies (0.96% of D-) were noted among 33,864 ethnically diverse patients over 18 months, of which 54 represented mutated RHD alleles. Seven obstetric patients were assigned D- status based on serology; only 1 patient had a partial RHD allele. Ten of 25 (36%) obstetric patients and 4 of 6 (67%) female potential transfusion recipients of childbearing age or younger were assigned D+ status, and they expressed a D variant known to permit anti-D alloimmunization. In total 20 RHD alleles were identified including category, DVa or DVa-like alleles (n = 7), DAR (n = 8), and four novel RHD alleles including two new DAU alleles.

Conclusion: Given the complexity of D antigen expression, it is concluded that some clinically important D variants identified by standard serologic analysis phenotype as D+ and are potentially at risk for the development of anti-D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alleles*
  • Amino Acid Substitution
  • Blood Banks / standards
  • Blood Group Incompatibility / epidemiology
  • Blood Group Incompatibility / etiology*
  • Blood Group Incompatibility / immunology
  • Blood Group Incompatibility / prevention & control
  • Blood Grouping and Crossmatching / standards
  • Blood Transfusion / standards
  • DNA Mutational Analysis
  • Erythroblastosis, Fetal / epidemiology
  • Erythroblastosis, Fetal / etiology
  • Erythroblastosis, Fetal / prevention & control
  • Ethnic Groups / genetics*
  • Exons / genetics
  • Female
  • Gene Frequency
  • Genotype
  • Humans
  • Immunity, Maternally-Acquired
  • Infant, Newborn
  • Isoantibodies / biosynthesis
  • Isoantibodies / immunology*
  • Male
  • Ontario / epidemiology
  • Phenotype
  • Point Mutation
  • Pregnancy
  • Prenatal Care / standards
  • Rh Isoimmunization / epidemiology
  • Rh Isoimmunization / etiology*
  • Rh Isoimmunization / immunology
  • Rh Isoimmunization / prevention & control
  • Rh-Hr Blood-Group System / classification
  • Rh-Hr Blood-Group System / genetics*
  • Rh-Hr Blood-Group System / immunology
  • Rho(D) Immune Globulin
  • Risk
  • Terminology as Topic
  • Transfusion Reaction*

Substances

  • Isoantibodies
  • RHO(D) antibody
  • Rh-Hr Blood-Group System
  • Rho(D) Immune Globulin
  • Rho(D) antigen