Anti-HLA Antibody Levels Are Associated With the Risk of Graft Failure After Allogeneic Hematopoietic Stem Cell Transplant.

OBJECTIVES: Allogeneic hematopoietic stem cell transplant provides a curative treatment for a considerable amount of hematologic diseases, and it is widely used today. Successful allogeneic stem cell transplant can be compromised by treatment-related toxicity, graft-versus-host disease, infectious complications, disease relapse, and graft failure. Primary graft failure is an important cause of hematopoietic stem cell transplant failure. Primary graft failure correlates with the level of complement-binding, donor-specific anti-HLA antibodies prior to transplant.

MATERIALS AND METHODS: We evaluated 15 patients who underwent hematopoietic stem cell transplant using peripheral blood stem cells in terms of graft failure and anti-HLA antibody levels before transplant. All were treated between January 2015 and June 2016. Pretreatment serum anti-HLA class I and anti-HLA class II antibody levels were measured in all patients.

RESULTS: Anti-HLA class I antibodies were present in 7 patients (46.6%) and anti-HLA class II antibodies in 8 (53.3%). All three patients who developed primary graft failure were anti-HLA-positive.

CONCLUSIONS: Anti-HLA antibodies are a significant cause of graft failure. It is a situation that must be understood with caution. Our results support the considerations that allogeneic hematopoietic stem cell transplant, especially when a fully compatible sibling donor is not present, should include screening of donor-specific antibodies of alternative donors and desensitization therapy for allosensitized patients before transplant.