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Weak D phenotypes and transfusion safety: where do we stand in daily practice?
Author(s) -
NoizatPirenne France,
Verdier Martine,
Lejealle Annette,
Mercadier Anne,
Bonin Philippe,
PeltierPujol Françoise,
FialaireLegendre Anne,
Tournamille Christophe,
Bierling Philippe,
AnsartPirenne Hélène
Publication year - 2007
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.2007.01332.x
Subject(s) - serology , typing , allele , population , medicine , antibody , antigen , blood transfusion , cutoff , immunology , biology , genetics , gene , physics , environmental health , quantum mechanics
BACKGROUND: Weak D Types 1, 2, and 3 recipients cannot be immunized when exposed to D antigen. Molecular biology is very efficient to type weak D variants but rarely implemented in daily practice. The serologic typing practice of weak D in a Caucasian patient population was analyzed and a transfusion strategy is proposed. STUDY DESIGN AND METHODS: Samples typed either ddCcee or ddccEe in routine laboratories were tested with the indirect antiglobulin test (D u test). D u ‐positive samples were screened for weak D alleles Types 1, 2, and 3 and further tested with immunoglobulin M (IgM) anti‐D reagents, used in a fully automated device. RESULTS: A total of 468 of 55,162 samples were found to be ddCcee or ddccEe. Ninety‐three expressed weak D after the D u test leading to D+ assignment for transfusion. Seventy‐three percent of D u ‐positive samples were weak D alleles Type 1, 2, or 3. Almost all weak D Types 1, 2, and 3 were positive with IgM reagents in gel matrix with an automated device. Other variants that could be potentially associated with anti‐D alloimmunization, however, were also positive. CONCLUSION: Serology is very sensitive to detect weak D Types 1, 2, and 3, but there is no cutoff to distinguish variants of clinical significance. When molecular analysis is not available, it is proposed that a D+ status for blood recipients found to be weak D with a sensitive method be assigned, except for women of childbearing age or younger, because of the remaining possibility to be partial D or other rare weak D who can be immunized.