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

• Published in: Transfusion (Philadelphia, Pa.) Pa.), 2005-10, Vol.45 (10), p.1554-1560
• Main Authors: Denomme, Gregory A., Wagner, Franz F., Fernandes, Bernard J., Li, Wei, Flegel, Willy A.
• Format: Article
• Language: English
• Subjects: Adult; Alleles; Amino Acid Substitution; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Blood and lymphatic vessels; 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; Blood. Blood and plasma substitutes. Blood products. Blood cells. Blood typing. Plasmapheresis. Apheresis; Cardiology. Vascular system; Clinical death. Palliative care. Organ gift and preservation; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; 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; Medical sciences; 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; Transfusions. Complications. Transfusion reactions. Cell and gene therapy
• ISSN: 0041-1132; 1537-2995
• DOI: 10.1111/j.1537-2995.2005.00586.x

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.