Incidence of weak D in blood donors typed as D positive by the Olympus PK 7200.
The incidence of weak D has been reported to be between 0.23 and 0.5 percent in Europe and 3.0 percent in the United States. All studies were performed before the introduction of monoclonal anti-D reagents. Using current commercial reagents, this study evaluated D+ samples for the presence of weak D. D+ donors, typed by the Olympus PK 7200, using diluted monoclonal blend anti-D and diluted polyclonal anti-D, were selected by sampling batches of 100 to 200 samples from the previous day's collection. Anti-D reagents used on the Olympus PK 7200 are required to detect RBCs with the weak D phenotype which do not agglutinate at immediate spin (IS) when tested with polyclonal anti-D by manual tube methods. More than 95 percent of donors tested were Caucasian. Using tube tests with two different monoclonal blend anti-D reagents and one polyclonal anti-D typing reagent, the presence or absence of the D antigen was evaluated after the IS reading. Donors found negative or weakly positive (< 2+) at IS were further typed for weak D by the IAT. The weak D samples were RHD genotyped by allele-specific PCR. Of 1,005 donors tested, 4 (0.4%) were classified as weak D by one or more anti-D reagents. Polyclonal anti-D reagent demonstrated weaker reactions when compared with the monoclonal blends. All weak D samples were found positive for exon 4, intron 4, and exon 10, a finding consistent with most D+ samples. The incidence of weak D found in this study is not significantly different from that found in earlier studies using polyclonal anti-D reagents.
BloodCenter of Wisconsin, Milwaukee, 53201-2178, USA.
C M
CM
Jenkins
S T
ST
Johnson
D B
DB
Bellissimo
J L
JL
Gottschall
D000483:Alleles; D001788:Blood Grouping and Crossmatching / Q000295:instrumentation / Q000592:standards; D005838:Genotype; D006801:Humans; D015994:Incidence; D007202:Indicators and Reagents / Q000737:chemistry / Q000592:standards; D007518:Isoantibodies / Q000737:chemistry; D016133:Polymerase Chain Reaction; D012204:Rh-Hr Blood-Group System / Q000032:analysis* / Q000235:genetics; D018029:Rho(D) Immune Globulin
D007202:Indicators and Reagents; D007518:Isoantibodies; C061961:RHO(D) antibody; D012204:Rh-Hr Blood-Group System; D018029:Rho(D) Immune Globulin; C026410:Rho(D) antigen