Introduction: Interleukin-2 (IL-2) is a cytokine that exerts its actions via binding to a variety of interleukin-2 receptors (IL-2R), thereby stimulating T-cell response. Acute renal graft rejection (AR) is known to be mediated by CD8+ T-cells, through the IL-2 pathway. The aim of this study was to determine whether IL-2 and IL-2R could work as prognostic biomarkers of AR.

Methods: IL-2, IL-2R and Cystatin-C levels were measured in the serum of 50 patients who underwent a kidney transplant, once pre-operatively and at four different time points post-operatively (second, sixth, 14th day and third month). Of the total number of patients, ultimately 10 (20%) had an episode of AR.

Results: No statistically significant difference in IL-2 levels was found between those who experienced AR and those who did not, at any of the studied time points. On the other hand, measurement of IL-2R levels on the sixth and 14th day post-operatively showed that people with AR had a statistically significant increase in its value compared to patients who did not have an AR episode (p=0.027 and p=0.019, respectively). In addition, comparing the values of IL-2R with that of Cystatin-C in different time periods, it was found that there is a significant positive linear correlation on the second and sixth postoperative day between the values of the associated parameters (r=0.280, p=0.049 and r=0.372, p=0.008 respectively).

Conclusion: The measurement of IL-2R from the sixth to 14th postoperative day could be used as a reliable prognostic biomarker of AR, however additional studies and standardised diagnostic thresholds are required before the routine clinical application is feasible.