ABSTRACT
Objective:To explore the critical value of different blood group antibody titration in ABO blood group incompatible kidney transplant(ABOi-KT)recipients by tube and gel methods to provide rationales for selecting the threshold value of antibody titration before ABOi-KT.Methods:From January 2019 to April 2021, 681 blood group antibody titrations were performed for 214 ABOi-KT recipients.There were type A( n=135), type B( n=168)and type O( n=378). The difference, correlation and consistency of two methods were statistically analyzed. Results:Tube method was 2 gradients lower than gel method(4-fold dilution)and the results were significantly different( P<0.000 1). Spearman's test indicated that the results of two methods were significantly correlated( P<0.000 1). The results of intraclass correlation coefficient showed that the consistency of two methods was general for type A recipients(ICC=0.640), decent for type B recipients(ICC=0.751)and poor for type O recipients(ICC<0.4). When the critical value of tube method was set, titration of type A anti-B was 16, titration of type B anti-A 8 and titration of type O anti-A/B 8.And the corresponding critical values of gel was type A anti-B 32, type B anti-A 16 and type O anti-A/B 16. Conclusions:The results of ABO blood group IgM antibody titration by gel and tube methods are correlative.And gel method is recommended for more stable and reproducible results.