ABSTRACT
【Objective】 To explore the identification method and characteristics of anti-IFC against Cromer blood group. 【Methods】 ABO blood group was identified by tube method, and Rh blood group was identified by Rh typing card. Irregular antibody screening and antibody identification were carried out using microtube column agglutination technology(MCAT). The serum of the patient reacted with panel cells treated with antitrypsin, trypsin and bromelain respectively to determine the specificity of the antibody. The serum was inhibited with pure CD55 protein for antibody identification. The DAF, the regulatory gene of Cromer blood group system, was amplified and sequenced. The expression of CD55 on cell membrane was analyzed by flow cytometry. 【Results】 The patient′s blood type was B, CcDEe. The patient′s serum reacted with all the untreated panel red cells, bromelain-treated red cells, trpsin-treated red cells, and DTT treated red cells.It was negative with chymotypsin-treated cells and could be neutralized by CD55 protein. No mutation was found by DAF sequencing. The expression of CD55 on patient′s cell membrane was deficient. 【Conclusion】 This high frequency antibody was identified as anti-IFC. The transient depression in CD55 protein may due to the patient′s GI system abnormalities.