A study of blood group conversion in patients with ABO incompatible hematopoietic stem cell transplantation—A decade survey

ABO incompatibility is not a contraindication but would affect the prognosis of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The dynamic change of blood phenotype is not only related to the patient's status, but also the basis for the implementation of compatible blood transfusion. The criteria for judging a complete transformation to donor-type and the principle of blood transfusion at relapse need to be unified. We aimed to illustrate the significance of blood group monitoring after allo-HSCT.We collected 263 patients underwent ABO incompatible allo-HSCT from January 2010 to December 2019, and monitored blood type regularly according to the frequency of the patient's return visits till complete conversion or death. Non-parametric test was used to find differences among incompatible groups. We analyzed factors potentially influence blood type conversion by Binary Logistic model. Cox regression model was used to illustrate the relationship between blood-type conversion and prognosis.The median days of conversion were 107, 91 and 108 in major-, minor- and bidirectional groups respectively. Blood type conversion correlated with HLA compatibility (P = 0.012, OR=2.69) and acute graft-versus-host-disease (P = 0.001, OR=0.06). Patients with incomplete blood type conversion had a higher death rate than those with complete blood type conversion(P = 0.003, OR=3.703).Blood type monitoring can help to evaluate the prognosis of transplantation and assess the risk of death. It is recommended to monitor the changes of blood group antigens and antibodies, especially within a year after transplantation, to predict the risk of adverse events (such as GVHD, recurrence, death, etc.).