Distinct immunohematologic features of the three D^VI types. The RhD antigen density is plotted on the ordinate. On the abscissa, the relative epitope detection by MCAD-6 is shown. This parameter was calculated as follows: [epitopes per cell detected by MCAD–6] ÷ [RhD antigen density] × 100%. Data of 15 D^VI samples and three controls are shown. ○, D^VI type I, n = 5; ▵, D^VI type II, n = 7; □, D^VI type III, n = 3; •, controls, n = 3.