Clinical and immunological features of very long-term survivors with a single renal transplant

The aim of this study was to analyze the clinical and immunological features of the 56 still alive patients at our institution harboring a functional first renal transplant since more than 30 years. The mean post-transplant graft survival in all patients was 35.4 ± 3.1 years, the mean serum creatinine concentration was 128.7 ± 7 μmol/l, and the mean urinary protein concentration was 0.6 ± 0.5 g/l. Fifty-one percent of the patients had experienced cancer involving the skin (46.1%) and/or other tissues (28%). Hepatocarcinoma was diagnosed in 11% of the patients with chronic viral hepatitis B and/or C (48%). The 5-year patient survival rate (considered after the 30th transplantation anniversary) was 27% in patients presenting a tumor versus 87% in those tumor-free (P < 0.0001). The thymic output, the proportions of the memory and naïve T cell subsets, and the frequencies of EBV- and CMV-reactive, IFN-γ-producing T cells did not differ from those observed in more recently transplanted patients. These results suggest that the impact of chronic immunosuppression on some immune functions does not worsen over time and that the observed high prevalence of cancer in these patients may be related to the synergistic effects of decreased immunosurveillance and the time required for carcinogenesis.