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

Authors

  • Gregory A. Denomme,

    Corresponding author
    1. From the Departments of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario; Canada; Research and Development, Canadian Blood Services, Toronto, Ontario, Canada; the Institute for Clinical Transfusion Medicine and Immunogenetics, Ulm, Germany; Red Cross Blood Services Baden-Württemberg–Hessen, Ulm, Germany; and the Red Cross Blood Services NSTOB, Institute Springe, Springe, Germany.
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  • Franz F. Wagner,

    1. From the Departments of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario; Canada; Research and Development, Canadian Blood Services, Toronto, Ontario, Canada; the Institute for Clinical Transfusion Medicine and Immunogenetics, Ulm, Germany; Red Cross Blood Services Baden-Württemberg–Hessen, Ulm, Germany; and the Red Cross Blood Services NSTOB, Institute Springe, Springe, Germany.
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  • Bernard J. Fernandes,

    1. From the Departments of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario; Canada; Research and Development, Canadian Blood Services, Toronto, Ontario, Canada; the Institute for Clinical Transfusion Medicine and Immunogenetics, Ulm, Germany; Red Cross Blood Services Baden-Württemberg–Hessen, Ulm, Germany; and the Red Cross Blood Services NSTOB, Institute Springe, Springe, Germany.
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  • Wei Li,

    1. From the Departments of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario; Canada; Research and Development, Canadian Blood Services, Toronto, Ontario, Canada; the Institute for Clinical Transfusion Medicine and Immunogenetics, Ulm, Germany; Red Cross Blood Services Baden-Württemberg–Hessen, Ulm, Germany; and the Red Cross Blood Services NSTOB, Institute Springe, Springe, Germany.
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  • Willy A. Flegel

    1. From the Departments of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario; Canada; Research and Development, Canadian Blood Services, Toronto, Ontario, Canada; the Institute for Clinical Transfusion Medicine and Immunogenetics, Ulm, Germany; Red Cross Blood Services Baden-Württemberg–Hessen, Ulm, Germany; and the Red Cross Blood Services NSTOB, Institute Springe, Springe, Germany.
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  • Supported in part by infrastructure grants from Pathology and Laboratory Medicine, Mount Sinai Hospital (19808-7874), and Research and Development, Canadian Blood Services (TO22656); by intramural research grants from the Blutspendedienst Baden-Württemberg—Hessen; and by the Deutsche Gesellschaft für Transfusionsmedizin und Immunhämatologie (Project DGTI/fle/2003-01).

Greg Denomme, PhD, Research and Development, Canadian Blood Services, 67 College Street, Toronto, Ontario, Canada M5G 2M1; e-mail: greg.denomme@bloodservices.ca.

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.

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