SEROLOGICAL CHARACTERISTICS OF PARTIAL D-ANTIGEN CATEGORY-VI IN 8 UNRELATED BLOOD-DONORS

Classification of subjects with a partial D antigen is traditionally p erformed with immune anti-D sera. The development of monoclonal antibo dies enables a fine analysis to be made of the specificity of the epit opes that are present or missing in these cases. A systematic search i n a Caucasian donor population of 17,500 revealed 8 unrelated male ind ividuals (frequency 0.05%) with a red cell phenotype characteristic of partial D category VI, but without anti-D in their serum. The relatio n to the 'classic' partial D category VI was investigated and is discu ssed, as is the observed serological heterogeneity of the partial D ca tegory VI group. Clinical consequences for the prevention of immunizat ion of these subjects are mentioned.