Abstract: Objective In order to reduce the risk of infection, the blood samples of patients suspected or diagnosed with novel coronavirus (SARS-Cov-2) were incubated at 56℃ for 30 minutes before serological blood typing in some laboratories. The influence of this method on pre-transfusion detection has not been systematically evaluated. In this study, we investigated the hemolysis rate, erythrocyte A, B, D antigen agglutination intensity and antibody titer of blood samples after this procedure. Methods The blood samples were randomly collected from blood donors and clinical patients in Shanghai, including 20 cases of type A, 20 cases of type B, 10 cases of type AB, 20 cases of type O (all of them were RHD positive), 7 cases of ABO subtype and 6 cases of D variant. The level of free hemoglobin was measured to evaluate the hemolysis rate. The detection of blood typing, antigen-antibody neutralization and antibody titer was to evaluate the agglutination intensity of A, B and D antigens and the changes of anti-A and anti-B titers. Results After the blood samples were incubated at 56℃, the RBC hemolysis rate was 1.87%±2.02%, and the agglutination intensity of A and B antigens decreased. The D antigens in normal D positive individuals did not decrease, while in D-variant individuals decreased. The titer of anti-A and anti-B antibody in serum decreased. Conclusion It was showed that after blood samples were incubated at 56℃, there was a low degree of hemolysis which did not affect serological blood typing, the agglutination intensity of A and B antigens and anti-A and anti-B antibodies decreased which was not strong enough to affect blood typing tests and only ABO subtype antigens may be affected.

Key words: 56℃ incubation, Hemolysis rate, ABO antigen, RHD antigen, SARS-Cov-2