To study the correct method for determining ABO blood types in infants and its influencing factors, blood types of 33 infants under 6 months old were determined by routine serological method, micro-column gel typing system and PCR-SSP genotyping method. Of the 33 cases with discrepant results of ABO blood type by different methods, the blood types of 32 cases were discrepant between red cell and serological typings in the routine serological method, and a false coincidence in 1 case was caused by bacterial infection resulting in B-like antigen. Correct blood typing was obtained in 27 cases with a correct rate of 84.4% (27/32) by using micro-column gel typing system. PCR-SSP method gave correct results in all of 33 cases. There was a significant difference between the results of micro-column gel typing system and PCR-SSP. It is concluded that to determine ABO blood type for infants < 6 months old, it is recommended to adopt micro-column gel typing system method, and what must be taken into account is the possible false coincidence caused by bacterial infection resulting in B-like antigen. In micro-column gel typing system, if the results of red cell and serological typing are identical, the principle is that blood transfusion must be performed with same ABO blood type between recipient and donor. If not, washed O red blood cells should be used for infants, and then change to transfusion with identical blood group according to PCR-SSP typing results.
ABO Blood-Group System Blood Grouping and Crossmatching