Clinical characteristics of renal transplant recipients who developed de novo donor-specific antigen in Kyoto University Hospital: a case series

Abstract

BackgroundThe clinical significance of de novo donor-specific antigen (DSA) in renal transplant recipients is not yet fully understood. This study aimed to report the prevalence of de novo DSA detected in antihuman leukocyte antigen (HLA) antibody testing and to evaluate the association between de novo DSA and renal transplant prognosis in living-donor renal transplant recipients at our hospital.MethodsOf the 110 patients who underwent living-donor renal transplantation from 1980 to 2019, 80 patients who underwent anti-HLA antibody screening tests were retrospectively reviewed for the development of de novo DSA and outcomes regarding graft function.ResultsThe mean age at transplantation was 43.2 ± 14.6 years. Of the 80 patients, 43 (53.8%) were men and 68 (85.0%) underwent ABO-compatible transplantation. Anti-HLA antibody was detected in 14 patients (17.5%), including eight (10.0%) with de novo DSA. Graft loss occurred in two (25%) of the eight patients with de novo DSA, none of the six patients with non-DSA anti-HLA antibody and no anti-HLA antibody (P = 0.0419, log-rank test). The mean estimated glomerular filtration rate at the time of the anti-HLA antibody test was 45.1 ± 14.4 mL/min/1.73m2 in the 66 patients with no anti-HLA antibody, while it was 35.0 ± 11.5 mL/min/1.73m2 in the eight patients with de novo DSA (P = 0.0702) and 39.3 ± 15.3 mL/min/1.73m2 in the six patients with non-DSA anti-HLA antibody (P = 0.3921). The mean monthly cyclosporin A trough concentration for the past year from the anti-HLA antibody test was 59.2 ± 24.8 ng/ml in the seven patients with no anti-HLA antibody, while it was 61.9 ± 12.5 ng/ml in the five patients with de novo DSA (P = 0.5670) and 36.3 ± 9.0 ng/ml in a patient with non-DSA anti-HLA antibody (P = 0.3921). The mean monthly tacrolimus trough concentration for the past year from the anti-HLA antibody test was 4.62 ± 1.20 ng/ml in the 55 patients with no anti-HLA antibody, while it was 4.09 ± 1.10 ng/ml in the three patients with de novo DSA (P = 0.0027) and 4.21 ± 1.14 ng/ml in the four patients with non-DSA anti-HLA antibody (P = 0.0722).ConclusionsThe optimal treatment for patients with de novo DSA has not been established, and immunosuppressive management that suppresses the development of de novo DSA is essential.