Response to treatment in kidney transplant recipients with acute antibody-mediated rejection: A follow-up biopsy study

BACKGROUND: The aim of this study is to evaluate the efficacy of a treatment protocol for the management of acute antibody-mediated rejection (AAMR) and mixed-type rejection (MTR), both histopathologically and clinically. MATERIALS AND METHODS: Of the 362 cases undergoing kidney transplantation from January 2010 to January 2018, patients with AAMR or MTR in the first 3 months after transplantation were included. All patients had follow-up biopsy (Bx) after treatment. RESULTS: 33 (9.1%) patients had diagnosis of AMR. Mean follow-up was 35 +/- 20 months. 28.5% of patients had poor clinical progression at the last follow-up. Of the 25 patients with functional grafts, the mean serum creatinine was 1.6 +/- 0.6 mg/dL for live and 2.1 +/- 1.0 mg/dL for deceased transplant recipients. In diagnostic biopsies, there were 61% MTR. In follow-up Bx, after treatment, both C4d positivity and the severity of rejection had decreased while the mean chronic allograft damage index (CADI) score and transplant glomerulopathy showed an increase. CONCLUSION: With effective antibody mediated rejection (AMR) therapy, renal function parameters were significantly improved. Histologically, improvement in tubulointerstitial inflammation may be responsible for this process. However, progressive chronic changes, particularly in the glomeruli, are noteworthy.