Effects of Reoptimization of Immunosuppressive Treatment on Donor-specific HLA Antibodies after Liver Transplantation

Abstract

Introduction: Donor-specific antibodies (DSAs) have negative effects on short- and long-term outcomes after organ transplantation. DSAs are prevalent in patients with low immunosuppression; thus, optimized immunosuppression is preferable even in patients with stable condition after liver transplantation. However, the effect of implementing immunosuppression reoptimization for patients with low immunosuppression remains unclear. In this study, we investigated long-term changes in DSA status and the effect of reoptimizing immunosuppression on DSA status. Methods: We retrospectively reviewed DSA status in 66 patients after liver transplantation in our center. Results: The median duration between first and second DSA evaluation was 50 months. Of the 66 patients, 43 were positive for class II DSAs in the first evaluation. Of these patients, 30 were found to have an insufficient dose of calcineurin inhibitor, or were immunosuppression free at the time of the first evaluation. Reoptimization of immunosuppression was then conducted for 20 of the 30 patients. Among the 20 patients, DSAs detected in the first evaluation became negative in 7 patients and mean fluorescence intensity (MFI) decreased in 9 patients. Compared with patients with sustained low immunosuppression, DSA levels significantly decreased in patients with reoptimized immunosuppression (p=0.005). Conclusion: The results of this study indicate that post-transplant reoptimization of immunosuppression improved DSA status after liver transplantation. Reoptimization of immunosuppression is considered to be especially preferable in patients with de novo DSAs, although the clinical significance of DSA negative conversion and/or MFI reduction needs to be further investigated.