[ABO incompatibility and complications in hematopoietic stem cell transplantation].

Background: Hematopoietic stem cell transplants (HSCT) can be performed regardless of the ABO group compatibility between donor and recipient. ABO incompatibility in HSCT is related to pure red cell aplasia (PRCA), or passenger lymphocyte syndrome. The impact of ABO incompatibility on graft-versus-host disease and transplant-related mortality is controversial due to the heterogeneity of procedures carried out in different transplant centers.

Objective: To determine the prevalence of ABO incompatibility and its complications in a hematopoietic stem transplant unit.

Material and methods: An observational, retrospective study was carried out in patients undergoing HSCT from January 2014 to January 2020. All trasplant patients were included. Qualitative variables were analyzed using chi-squared test, and Wilcoxon and Student's t tests were used for quantitative variables. A p < 0.05 was considered significant.

Results: 124 patients undergoing HSCT were analyzed, out of which 31 had ABO incompatibility, with a punctual prevalence of 24.4%; among them, 54% presented with major incompatibility, 32% minor incompatibility and 13% bidirectional incompatibility. Three cases of PRCA were reported. There were no differences in survival at one year in both groups.

Conclusions: The ABO incompatibility ant its complications were not related to the increase in mortality. Randomized prospective studies are required to define the role of ABO incompatibility in HSCT prognosis.