Is the d an allelic gene of D in the Rh blood group system? A quantitative study using...

This article reports on studies of Rh antigens, such as D, Du and d, using uranyl-labelled antibody (ULA) and TcLA (99mTc-pyrophosphate-labelled antibody) methods for the first time for this purpose. TcLA method proved to be simple in labelling and very sensitive (20--100 times more so than the indirect Coombs test) in the detection of Rh antigen-antibody binding. Results of this quantitative study demonstrate convincingly that the d is not an allelic gene of D but rather the weakest of the series D less than Du less than d. Although the evidence from this study demonstrates clearly that differences between D and d are only quantitative, the authors do not think that the Rh nomenclature should be changed but they do think that the present evidence should be used in regard to the understanding of the allelism in the Rh blood group system. The c is an allelic gene of C as the e is an allelic gene of E; specific test sera detecting every one of these antigens exist and the family studies verify these statements. However, the d is not a distinct antigen as c and e are, even if the pattern of inheritance from family studies, using the existent anti-D serum, would suggest the allelism as probability. That is why in the past the anti-Du and anti-d specific test sera never incidentally found or artificially produced.