The invention relates to a method for determining whether a renal transplanted patient is at risk of transplant rejection or CAN, comprising a step of determining the expression level of the periostin (POSTN) gene on a renal transplant biopsy obtained from said transplanted patient. The invention also relates to a compound selected from the group consisting of monoclonal anti-CD20 antibodies, anti-thymocyte globulin, proteasome inhibitors, anti-C antibodies, monoclonal anti-CD3 antibodies, glucocorticoids, cytostatics, calcineurin inhibitors and mTOR inhibitors, for use in a method for preventing renal transplant rejection and in CAN development in a transplanted patient determined as being at risk of renal transplant rejection according to a method of the invention.
