Abstract: Objective To discuss the identification method of polyagglutination of red blood cells by T-antigen exposure in children with necrotizing enterocolitis (NEC) to formulate transfusion strategies to provide reference for clinical guidance and scientific and rational use of blood in children. Methods ABO and Rh blood group identification, direct antiglobulin test (DAT), antibody screening test and cross-matching test were performed in 2 NEC children with difficult cross-matching difficulty in our center. Erythrocyte polyagglutination was found in 3 ABO donor plasma, 3 AB donor plasma and 3 umbilical cord blood plasma. The polyagglutination was further identified by Peanut Agglutinin, MN Blood Group Reagent and Polybrene test. Results The erythrocyte antibody screening test, DAT and major cross-matching test were negative in 2 cases. The minor cross-matching test using saline and anti-human globulin test were positive. The red blood cells of the children were positive with plasma from donor of the same blood type and AB plasma, and negative with cord blood plasma of the same blood type. MN blood group antigen was negative in children who were positive with Peanut Agglutinin. No expected agglutination was observed with Polybrene test. Conclusion NEC children with polyagglutinated erythrocytes showed negative DAT tests and positive minor cross-matching tests. At this time, multiple methods should be used to identify the phenomenon of erythrocyte polyagglutination to choose appropriate blood products to avoid delayed transfusion.

Key words: Necrotizing enterocolitis, T antigen exposure, Red blood cell polyagglutination, Cross-matching, Transfusion strategy