A comparative analysis of kidney allograft outcomes in steroid use versus steroid discontinuation after basiliximab and ATG induction: A UNOS database study.

BACKGROUND AND OBJECTIVES: The relative safety and efficacy of early steroid withdrawal in kidney transplant patients after basiliximab compared to anti-thymocyte globulin (ATG) induction therapy is unknown. We aimed to compare kidney allograft outcomes in steroid use versus steroid discontinuation after basiliximab and ATG induction from the United Network for Organ Sharing (UNOS) database. MATERIALS AND METHODS: We conducted a retrospective cohort analysis of the UNOS database and included first kidney transplant recipients who received ATG or basiliximab induction therapy. We compared graft and patient outcomes in those who received steroid maintenance and those who were discharged off steroids. RESULTS: Of 106,061 patients, 25,344 (86.7%) received basiliximab induction and were maintained on steroids (B-Sm), and 3,880 (13.3%) were on a steroid-free regimen (B-Sf). Graft failure rate was significantly higher in the B-Sf compared to B-Sm at 1-year (4.1 vs. 1.8%, p < 0.001), 3-year (6.0 vs. 4.3%, p < 0.001) and 5-year follow-up (7.7 vs. 6.4%, p = 0.0004). The mortality rate was significantly higher in B-Sf at 1-year (3.3 vs. 2.4%, p = 0.0005), 3-year (7.6 vs. 5.5%, p < 0.001) and 5-year follow-up (11.5 vs. 8.8%, p < 0.001) when compared to the B-Sm. 76,837 recipients received ATG induction therapy, 51,745 (72.4%) were on steroid maintenance therapy (A-Sm) and 25,092 (32.6%) were on a steroid-free regimen (A-Sf). The graft failure rate was significantly higher in A-Sf compared to A-Sm at 1-year follow-up (2.6 vs. 2.3%, p = 0.0006), however, there was no difference at 3-year (5.0 vs. 5.0%, p = 0.53) or 5-year follow-up (7.2 vs. 8.1%, p = 0.17). There was no difference in mortality rates between A-Sf vs. A-Sm at 1 year (2.5 vs. 2.4%, p = 0.98) and at 3 years (5.5 vs. 5.4%, p = 0.45), respectively. CONCLUSION: Patients who were maintained on steroids after basiliximab induction had better 5-year allograft survival and patient survival compared to those who were not maintained on steroids. However, steroid maintenance conferred no additional benefit after ATG induction and was associated with higher mortality.

Protocol-based donor-derived cell-free DNA surveillance in kidney transplant recipients: A single-center experience.

AIMS: Donor-derived cell-free DNA (dd-cfDNA) surveillance testing has never been studied in comparison with other surveillance tests. In this study we aim to describe our center's clinical experience with routine dd-cfDNA monitoring and to assess whether monitoring dd-cfDNA by protocol provides additional information that aids in detection of acute rejection. MATERIALS AND METHODS: We implemented the dd-cfDNA (Allosure) surveillance protocol in addition to measurements of serum creatinine, proteinuria, and donor-Specific antibody. We retrospectively reviewed all kidney recipients transplanted from July 2018 to April 2020. 366 dd-cfDNA test results were reviewed from 82 patients. RESULTS: There were 13/366 positive dd-cfDNA tests in 8/82 patients. Five of the 8 patients had kidney biopsy which showed: 3 rejections (1 antibody-mediated rejection, 1 T-cell-mediated rejection, and 1 mixed), 1 acute tubular necrosis, and 1 transplant glomerulopathy. The remaining 3 patients did not undergo a biopsy and repeat dd-cfDNA testing improved without intervention. In the 353/366 negative dd-cfDNA tests in 74 patients: 7 patients underwent a biopsy: 1 patient with increased creatinine showed borderline cellular rejection, 3 had recurrent disease (membranoproliferative glomerulonephritis, diabetes mellitus, immunoglobulin A nephropathy), and 3 showed interstitial fibrosis and tubular atrophy. dd-cfDNA levels were not elevated in recipients with infection (BK viruria/viremia, CMV viremia, or urinary tract infection (UTI). CONCLUSION: The addition of surveillance dd-cfDNA testing resulted in marginal added benefit. Whether this offsets the cost of testing needs to be further explored. In our cohort of low-risk patients, the cost of protocol dd-cfDNA testing may not be justified by its limited benefits.