PREVALENCE OF ANTI-HLA ANTIBODIES IN HAPLOIDENTICAL HEMATOPOIETIC STEM CELL TRANSPLANTATION IN PEDIATRIC PATIENTS : A SINGLE-CENTER EXPERIENCE

Allogeneic hematopoietic cell transplantation (HCT) remains the curative treatment of many patients with relapsed and refractory hematologic malignancies, and some non-malignant conditions. For patients with no matched donors, haplo-identical donors have been used successfully over the last decade. Some donors may have antibodies directed against the recipient’s HLA antigens often referred to as donor-specific antibodies (DSAs). The use of stem cells from such donors may increase the risk of primary graft failure. In order to determine if the presence of human leukocyte antigen (HLA) donor-specific antibodies (DSA) at the time of HCT increases the risk of primary graft failure in HLA haploidentical transplantation, we reviewed the presence of anti-HLA antibodies and DSA before transplantation in the first 100 consecutive HLA haploidentical transplant in pediatric patients at our centre. Solid phase antibody assays were used for testing. Results showed HLA antibodies were detected in 50/100 (50%) of the patients. Of the 50 sensitized patients twenty (n=20) had DSA. Twelve (n=12) of the 20 patients with DSA had cumulative mean fluorescent index (MFI) 2000 MFI. Four among these underwent desensitization and all of them achieved engrftment.. Two of the four patients with positive DSA and no desensatization developed graft rejection and the other two patient engrafted.