MO1001: Tocilizumab in the Treatment of Chronic Antibody-Mediated Rejection Post Kidney Transplantation: Clinical and Histological Monitoring

Abstract

BACKGROUND AND AIMS Chronic antibody-mediated rejection (cAMR) has very few effective therapeutic options. Interleukin-6 is an attractive target because it is involved in inflammation and humoral immunity. Therefore, the use of tocilizumab (anti-IL6 receptor, TCZ) is a potential valuable therapeutic option to treat cABMR in kidney-transplant (KT) recipients METHOD This single-centre retrospective study included all KT recipients that received monthly TCZ infusions in the setting of cABMR, between August 2018 and July 2021. We assessed 12-month renal function and KT histology during follow-up. RESULTS Forty patients were included. At 12-months, eGFR was not significantly different, 41.6 ± 17 versus 43 ± 17 mL/min/1.73 m2 (P = .102) in patients with functional graft. Six patients (15%) lost their grafts: Their condition was clinically more severe at the time of the first TCZ infusion. Histological follow-up showed no statistical difference in the scores of glomerulitis, peritubular capillaritis, and interstitial fibrosis/tubular atrophy (IFTA). However, the chronic glomerulopathy score, increased significantly over time, and conversely, arteritis and inflammation in IFTA ares improved in follow-up biopsies. CONCLUSION In our study, the addition of TCZ prevented clinical and histological worsening of cABMR in KT recipients, except for more severely ill patients. Randomized studies are needed to clarify the risk/benefit of TCZ in cABMR.