PREVALENCE OF ANTI-HLA ANTIBODIES IN HAPLOIDENTICAL HEMATOPOIETIC STEM
CELL TRANSPLANTATION IN PEDIATRIC PATIENTS : A SINGLE-CENTER EXPERIENCE
Abstract
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 and underwent
transplant without desensitization and all were engrafted. Whereas eight
patients had 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.