Impact of immunosuppression intensified conditioning regimen for patients with strong positive pre-transplantation donor-specific anti-HLA antibodies (DSAs) undergoing haploidentical hematopoietic stem cell transplantation

Abstract

Objective: To explore the efficacy of immunosuppression intensified conditioning regimen in patients who have strongly positive donor-specific Anti-HLA antibodies (DSAs) and received a haploidentical hematopoietic stem cell transplantation (haplo-HSCT) . Methods: Clinical data of 10 patients with strongly positive pretransplant DSAs (defined as MFI ≥10000) were retrospectively analyzed in this study. All of them received a haplo-HSCT in the Hematology Department of Shanghai Zhaxin Traditional Chinese & Western Medicine Hospital. Results: ① Of all ten patients, three were males, and seven were females, with a median age of 53.5 (36-64) years. Of the 10 patients, three were diagnosed with acute myeloid leukemia, two were myelodysplastic syndromes (MDS), two were chronic myelomonocytic leukemia (CMML), two were in an accelerated phase of chronic myeloid leukemia (CML-AP), and one was primary myelofibrosis (PMF). ② Conditioning regimen consisted of fludarabine (Flu) /busulfan (Bu) combined with whole-body irradiation (TBI) /cyclophosphamide (Cy). ③ On the seventh day after transplantation, the median pretransplant DSA level was MFI 15 999 (10 210-23 417) and 10 787 (0-22 720). ④ Eight patients acquired hematopoietic reconstitution; the median time of neutrophil engraftment was 14 (10-16) days; and 18 (14-20) days for platelet engraftment. After a median follow-up of 12.5 (1.5-27) months, primary graft failure was found in one patient and another with poor graft function. Seven patients remained in a disease remission state, and all were DSA-negative. Conclusions: An intensified immunosuppression conditioning regimen can efficiently decrease the level of donor-specific anti-HLA antibodies (DSAs), leading to good short-term efficacy.