Further complexities of the Rh antigen D disclosed by testing category DII cells with monoclonal anti-D

The reaction pattern of monoclonal anti-D with category DII cells differed from those of other category D cells. DII cells express epD1, epD2, epD3, epD5, epD6/7 and epD8 but lack epD4 and a new epitope epD9. The new epitope, epD9, is proposed to explain the failure of some monoclonal anti-D (previously considered to be anti-epD3) to react with DII cells.