S118 IMPACT OF PRE‐TRANSPLANT DONOR‐SPECIFIC ANTI‐HLA ANTIBODIES IN CORD BLOOD TRANSPLANTATION ON BEHALF OF THE TRANSPLANT COMPLICATIONS WORKING GROUP OF JSHCT

Abstract

Background:Cord blood transplant (CBT) is an effective treatment for hematological diseases. Graft failure (GF) remains a major complication of CBT. Although presence of pre‐transplant donor‐specific anti‐HLA antibody (DSA) was reported to be associated with an increased risk of GF after CBT, data is still limited.Aims:In order to clarify the impact of pre‐transplant DSA, we conducted a retrospective analysis of recipients of CBT with pre‐transplant anti‐HLA antibody using the database of Japan Society for Hematopoietic Cell Transplantation (JSHCT).Methods:Data for recipients of CBT with pre‐transplant anti‐HLA antibody from 2010 to 2014 were obtained from the Transplant Registry Unified Management Program. Additional data such as detailed information about anti‐HLA antibody were collected. This study was approved by the institutional review boards of the JSHCT and Oita University.Results:In total, 343 patients who received CBT with detailed information about anti‐HLA antibody were included in the further analysis. Median age was 51 years (range, 0 to 71). Regarding DSA, 25 patients had mean fluorescence intensity (MFI) >1000 (DSA‐positive group) and 318 patients had MFI<1000 (DSA‐negative group). Cumulative incidence of neutrophil engraftment at 60 days after CBT was 75.7% (95% CI, 70.6–80.1) in the DSA‐negative group and 56.0% (95% CI, 34.1–73.1) in the DSA‐positive group (P = 0.03, Figure). Grouped according to the HLA class of DSA, cumulative incidence of neutrophil engraftment was 71.4% in patients with DSA against HLA class II antigen (n = 14), 44.4% in those with DSA against HLA class I antigen (n = 9), 0% in those with DSA against both HLA class I and class II antigens (n = 2). Stratified according to the achievement of neutrophil engraftment, the probabilities of overall survival at 1 year after CBT were 62.7% (95% CI, 56.2–68.5) in the engrafted patients and 19.5% (11.8–28.5) in the non‐engrafted patients (P < 0.001).Summary/Conclusion:Our study is a largest cohort of CBT recipients with pre‐transplant anti‐HLA antibody. Pre‐transplant DSA was associated with an increased risk of GF. The importance of target HLA antigen should be clarified in the future study.image