4661 KIDNEY TRANSPLANTATION IN PATIENTS WITH ANCA-ASSOCIATED VASCULITIS IS ASSOCIATED WITH A HIGH INCIDENCE OF POST-TRANSPLANT CANCER

Abstract Background and Aims Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are challenging systemic diseases. Kidney transplantation is the treatment of choice for patients with AAV and end stage kidney disease.[1] AAV relapses after transplantation are rare and data regarding AAV recurrences in this setting are lacking.[2] Method In this single-centre retrospective cohort study, we analyzed the data from medical records of adult patients transplanted at our transplant Center between February 2006 and January 2022 and followed at the Nephrology Unit of the same Hospital: Fondazione IRCCS Cà Granda Ospedale Policlinico in Milan. Results We identified 9 patients on 1026 with a pre-transplant diagnosis of AAV; all patients had received previous treatment with cyclophosphamide. Maintenance immunosuppression after transplant was tacrolimus-based in 89% of the patients. At the end of a median follow-up of 132 ± 61.1 months after transplantation, only one case of extra-renal vasculitis relapse was observed (Table 1). The relapse rate was 0.01 per patient per year comparable to what reported in the literature. However, seven patients were diagnosed with cancer after a median follow-up of 81.4 ± 35.8 months after transplantation; six had skin cancer and three a renal cell carcinoma of the native kidneys (cumulative incidence of 78%). One patient died from metastatic spinous cell carcinoma. We therefore decided to make a narrative comparison between this cohort and a previous series published by our group including 19 patients transplanted between December 1987 and January 2006.[3] In the older cohort we reported 7 relapses and a relapse-rate of 0.076 per patient per year (Table 2). Table 1: Follow-up and outcome. Serum Proteinuria Follow-up Creatinine mg/dl g/L No after TX (mo) Mo 1 Mo 12 Last Follow-up Mo 1 Mo 12 Last Follow-up AAV relapse Cancer Infection 1 142 1 1 1 0.09 0.06 0.16 Y 0 COVID-19 pneumonia 2 192 0.9 0.9 0.8 0.2 0.2 0.12 N RCC 0 3 127 1.2 1.5 1.4 0.08 0.06 0.08 N RCC-USCC 0 4 90 2.4 2 1.7 0.16 0.12 0.06 N SCC CMV 5 136 1.1 1.7 1.3 0.2 0.18 0.1 N RCC Bacterial pneumonia 6 93 1.3 1.3 1 0.2 0.14 0.26 N BCC 0 7 197 0.8 1.1 1.1 0.8 1.1 1.1 N SCC EBV 8 198 1 1.1 0.9 0.18 0.09 0.09 N SCC-BCC 0 9 12 1.6 1.9 2.4 0.1 0.4 0.9 N 0 CMV Abbreviations: RCC Renal-Cell carcinoma, USCC Undifferentiated squamous-cell carcinoma, SCC Squamous-Cell carcinoma, BCC Basal-Cell carcinoma, COVID-19 Coronavirus Disease 19, CMV Cytomegalovirus, EBV Epst