Abstract
The long‐term stability of renal grafts depends on the absence of chronic rejection. As T cells play a key role in rejection processes, analyzing the T‐cell repertoire may be useful for understanding graft function outcomes. We have therefore investigated the power of a new statistical tool, used to analyze the peripheral blood TCR repertoire, for determining immunological differences in a group of 229 stable renal transplant patients undergoing immunosuppression. Despite selecting the patients according to stringent criteria, the patients displayed heterogeneous T‐cell repertoire usage, ranging from unbiased to highly selected TCR repertoires; a skewed TCR repertoire correlating with an increase in the CD8^+^/CD4^+^ T‐cell ratio. T‐cell repertoire patterns were compared in patients with clinically opposing outcomes i.e. stable drug‐free operationally tolerant recipients and patients with the “suspicious” form of humoral chronic rejection and were found significantly different, from polyclonal to highly selected TCR repertoires, respectively. Moreover, a selected TCR repertoire was found to positively correlate with the Banff score grade. Collectively, these data suggest that TCR repertoire categorization might be included in the calculation of a composite score for the follow‐up of patients after kidney transplantation.