Impact of transplant accessibility for sensitized patients by avoiding unacceptable antigens.

ABSTRACT

Recent data have confirmed the negative impact of preformed donor-specific antibodies (pDSAs) after liver transplantation (LT). In order to reduce the risk of developing lesions associated with acute and chronic antibody-mediated rejection in LT recipients, we evaluated the consequences in terms of transplant accessibility, associated with avoiding pDSAs according to several mean fluorescence intensity (MFI) titer thresholds that have been previously reported to be relevant in LT. Among the 484 included LT candidates, 99 (20.5%) presented with anti-human leukocyte antibodies (HLAs). The predictive factors for anti-HLA sensitization were a history of previous kidney transplantation (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.30-1.9; P = 0.05), a history of previous LT (OR, 1.9; 95% CI, 1.6-2.1; P = 0.01), a history of blood transfusion (OR, 2.5; 95% CI, 2.2-4.1; P = 0.01), and a history of pregnancy (OR, 2.9; 95% CI, 2.4-3.3; P = 0.04). By applying a strategy of unacceptable mismatches for recipients with an antibody (Ab) MFI of > 5000, only 35 patients were affected (7% of the cohort), but 22 of these (63%) would have been considered incompatible with >50% of the donors. Using a MFI threshold of >10,000, only 16 patients were affected (1.4% of the cohort), but half of these would have been considered incompatible with >50% of the proposed donors. Considering only those with anti-class II Ab and a MFI >5000 and >10,000, respectively, 10/14 and 4/8 patients were considered incompatible with >50% of the donors. In conclusion, avoiding pDSAs affects a small but not negligible proportion of LT candidates. However, in these sensitive patients, avoiding pDSAs has the potential to significantly reduce the donor pool and, consequently, transplant accessibility. Liver Transplantation 23 880-886 2017 AASLD.