Probability of anti-D development in D- patients receiving D+ RBCs.
BACKGROUND
In some situations, the administration of D+ RBCs to D- patients is necessary. The probability of a subsequent anti-D formation is assumed to be around 80 percent, a figure based primarily on studies in healthy volunteers. It was hypothesized that patients requiring blood transfusion have a much lower probability of developing antibodies.


METHODS
A retrospective analysis was performed whereby 78 D- patients were evaluated for the development of RBC antibodies after administration of D+ RBCs. For the analysis of the cross-sectional observations, parametric models were used for interval-censored data.


RESULTS
Anti-D was detected in 16 of 78 patients. Considering the individual patient's inspection times, the calculated probability of developing antibody following D+ RBC supply was shown to be below 41.7 percent (upper 95% confidence bound) and estimated as 30.4 percent. The data hinted toward an inverse correlation between the number of transfused units and the probability of antibody formation. Interestingly, 6 of these 16 patients developed additional IgG autoantibody. In 3 of those cases, evidence for prolonged hemolysis was found.


CONCLUSIONS
The actual frequency of antibody formation in our patients is much lower than assumed. On the other hand, prolonged hemolysis probably induced by additional autoreactive antibodies might occur. This possible complication has not yet been addressed. Further studies might reveal whether a less restricted transfusion policy with respect to D matching is justified in selected patients.
Frohn
Christoph
C
Institute of Immunology and Transfusion Medicine, University of Lübeck, Lübeck, Germany. Frohn@immu.mu-luebeck.de
Dümbgen
Lutz
L
Brand
Jörg-Matthias
JM
Görg
Siegfried
S
Luhm
Jürgen
J
Kirchner
Holger
H
D000328:Adult; D000368:Aged; D000917:Antibody Formation; D001323:Autoantibodies / Q000097:blood; D001787:Blood Group Incompatibility / Q000276:immunology*; D017707:Erythrocyte Transfusion; D005260:Female; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012204:Rh-Hr Blood-Group System / Q000276:immunology*; D013997:Time Factors
D001323:Autoantibodies; D007518:Isoantibodies; D012204:Rh-Hr Blood-Group System