Donor-to-Recipient ABO Mismatch Does Not Impact Outcomes of Allogeneic Hematopoietic Cell Transplantation Regardless of Graft Source

Abstract

The impact of ABO mismatch has been studied on various hematopoietic cell transplant (HCT) outcomes including neutrophil and platelet engraftment, pure red cell aplasia (PRCA), acute and chronic GVHD, non-relapse mortality (NRM) and overall survival (OS). Yet conflicting results have been reported. However, the impact of ABO mismatch on transplant outcomes with various graft types has not been carefully investigated. We analyzed the impact of various graft sources and type of ABO mismatch on transplant outcomes for 1502 patients who underwent HCT at the University of Minnesota, between 2000–2014: 312 receiving marrow (BM), 475 filgrastim-mobilized blood (PBSC), and 715 cord blood (UCB) grafts. Neutrophil engraftment by day 28 was marginally less frequent in the bidirectional ABO mismatched transplants receiving UCB while ABO matching had no influence on engraftment in the BM or PBSC cohorts. ABO mismatch led to no significant differences in platelet engraftment irrespective of stem cell source. We observed a modest, but not significantly lower incidence of grade II/IV acute GVHD in the bidirectional ABO mismatched transplants in the UCB and the PBSC cohorts, but not in the BM group. We found a higher incidence of chronic GVHD in the PBSC group, but it was not significantly lower in the minor ABO mismatched transplants. The incidence of chronic GVHD was similar in the major ABO mismatched transplants receiving BM. We found no significant difference in the overall survival (OS) and non-relapse mortality (NRM) between the ABO matched and the ABO mismatched transplants within each of the three graft source groups. Multivariable analysis adjusting for other relevant factors confirmed that ABO match status did not significantly influence the outcomes of either engraftment, acute or chronic GVHD or NRM. We conclude that ABO mismatch does not influence the outcomes of allogeneic HCT, regardless of stem cell source.

Who is the best haploidentical donor for acquired severe aplastic anemia? Experience from a multicenter study

“…Ozkurt et al reported more frequent severe aGVHD among minor ABO-mismatched patients [32], but Kimura et al found a high incidence of severe aGVHD in both major and minor ABO mismatches [33]. There were also conflicting results that failed to find a difference in rates of aGVHD between minor ABO incompatibility and others [34–36]. No evidence of an association between the ABO mismatch and cGVHD or survival was observed in this study.…”

Optimizing selection of double cord blood units for transplantation of adult patients with malignant diseases

“…Conversely, the association of ABO matching with OS has not been previously reported in UCBT to our knowledge, but previous studies included none or only few DUCB transplants. [28][29][30] In the present analysis, ABO matching remained a significant risk factor for OS after adjusting for potential confounders, although it is important to note that its effect size was small with borderline significance. We also looked at the influence of interunit ABO match on survival but did not find any association.…”

ABO Mismatch in Allogeneic Hematopoietic Stem Cell Transplant: Effect on Short- and Long-term Outcomes

“… 29 This finding was subsequently confirmed in the haploidentical setting. 7 In contrast, Damodar et al 5 reported no effect of ABO-mismatch on aGVHD and survival of 1502 patients analyzed by graft sources. Regarding our patients, we failed to observe any effect of ABO mismatch on aGVHD so that the higher NRM in our series conceivably relies on other causes.…”