RH PHENOTYPES OF CHINESE BLOOD-DONORS IN HONG-KONG, WITH SPECIAL REFERENCE TO WEAK D-ANTIGENS

Among Hong Kong Chinese blood donors, 99.71 percent were found to be D+. Of these, 55.02 percent were of the phenotype CCDee. The D(u) phenotype was found to be present in 0.01 6 percent. Among the 0.27 percent who were apparently D-, 0.079 percent were of the D(el) phenotype, while the remaining 0.1 9 percent were ''true D-,'' as defined by a nonreactive eluate obtained by an adsorption and elution procedure using anti-D. The ccdee phenotype constitutes 56.77 percent of the ''apparent D- '' and 80.24 percent of the true D -. Data show that anti-D rarely occurs in Hong Kong Chinese, and it is postulated that this could be due to the presence of a very weak form of the D antigen among many of those who appear to be D-.