Donor-specific antibodies (DSA) can lead to graft failure in patients who receive a human leukocyte antigen (HLA)-mismatched haploidentical hematopoietic stem-cell transplantation (HSCT). However, the presence of DSA did not lead to graft failure or impact the graft-versus-host disease (GVHD) incidence in patients who received haploidentical HSCT, according to research presented at the Tenth Annual Meeting of the Society of Hematologic Oncology (SOHO).
Majed Altareb, MD, of the King Faisal Specialist Hospital & Research Center in Riyadh, Saudi Arabia, conducted the single-center retrospective analysis and presented its results at the SOHO meeting.
The researchers aimed to study the impact of DSA and anti-HLA antibodies in patients who received haploidentical HSCT for malignant hematological diseases because the presence of DSA is associated with poor graft function and graft failure in patients who receive a mismatched-HLA transplant.
“Despite the availability of potential donors, transplant physicians still face scenarios where the recipient has DSA against the appropriate donor,” Dr. Altareb and colleagues wrote. “If alternative donors are not available, desensitization to remove the alloantibodies from the recipient’s serum ahead of transplant is recommended to minimize the risk of [graft failure].”
The researchers identified 107 patients who received myeloablative haploidentical HSCT for malignant hematological diseases. Most patients were male (58%), and the median patient age was 22 years (range, 1-56 years). Most donor-recipient pairs (71%) had matched ABO blood groups, and the graft source was bone marrow in 78% of patients. The median infused CD34 cell dose was 4.02×106/kg (range, 1.3-13.1). More than half of patients (57%) were positive for anti-HLA, and 28% of those patients had DSA, representing 15% of the study population. Approximately a third (29%) of patients with DSA underwent desensitization.
The incidence of acute GVHD and chronic GVHD were comparable between patients with and without anti-HLA antibodies, and between patients with and without DSA. Overall survival and the cumulative incidence of relapse were also comparable between patients with and without anti-HLA antibodies, and between patients with and without DSA.
Researchers reported graft failure in 2.8% of patients, with 1 primary graft failure due to a low dose of CD34. No graft failures occurred in patients with anti-HLA antibodies or DSA. The median time to graft failure was 2.23 months (range, 0.8-2.89 months).
“Our study shows that desensitization may not be required in the setting of myeloablative transplant for malignant hematological disorders,” Dr. Altareb and colleagues concluded. “This warrants further investigations in prospective trials.”
Altareb M, Alawwami M, Aljurf M, El Fakih R. Prevalence and impact of donor specific anti-HLA antibodies in the setting of myeloablative haploidentical transplant for malignant hematological diseases: single-center experience. Poster CT-026. Presented at the Tenth Annual Meeting of the Society of Hematologic Oncology; September 28-October 1, 2022; Houston, TX.