ABO Incompatibility and Hematopoietic Stem Cell Transplantation Outcomes

Area of Science:

• Hematology
• Transplantation Immunology

Background:

• ABO incompatibility in hematopoietic stem cell transplantation (HSCT) is linked to hemolytic reactions and delayed erythrocyte recovery.
• The impact of ABO incompatibility on broader HSCT outcomes requires further investigation.

Purpose of the Study:

• To evaluate the effects of ABO incompatibility on various outcomes in allogeneic HSCT.
• To compare outcomes between matched and mismatched ABO compatibility groups.

Main Methods:

• Prospective follow-up of 501 patients undergoing allogeneic HSCT.
• Categorization of patients into minor, major, bidirectional mismatched, and matched ABO compatibility groups.
• Analysis of outcomes including overall survival, transfusion requirements, and specific complications.

Main Results:

• Lower overall survival (OS) observed in the minor mismatched group (p=0.017).
• Increased packed red cell units transfused in minor and bidirectional mismatched groups compared to matched controls.
• Higher platelet unit transfusions in major mismatched recipients.
• Two cases of pure red cell aplasia (PRCA) noted in the major mismatched group.

Conclusions:

• ABO-incompatible HSCT is associated with decreased OS and increased transfusion requirements.
• Selecting ABO-compatible donors is crucial for improving HSCT outcomes and mitigating complications.
• While some complications are linked to ABO mismatch, key metrics like GVHD and relapse rates showed no significant differences.