[Detection of rare rhesus antigens Cx and Ew using monoclonal and polyclonal antibodies in routine laboratory tests].

Two cases are described in whom rare antigens of the rhesus blood group system could be found by absent or very weak reaction with monoclonal antisera and strong reaction with polyclonal reagents. All 3 monoclonal anti-E sera showed no reaction with the Ew antigen, while monoclonal anti-C sera had different reactions with the Cx antigen.