Natural Killer Cell Subsets and IL-2, IL-15, and IL-18 Genes Expressions in Chronic Kidney Allograft Dysfunction and Graft Function in Kidney Allograft Recipients

BACKGROUND While acute rejection and early graft loss rates have decreased substantially over the past four decades, progressive chronic allograft dysfunction (CAD) still remains a common cause of late graft loss in kidney transplant recipients. OBJECTIVE This study was conducted to investigate the percentage of natural killer (NK) cell subsets and IL-2, 15 and 18 genes expression in two groups of CAD and well-function graft (WFG) recipients. METHODS 30 renal allograft recipients with biopsy-proven interstitial fibrosis/tubular atrophy (IF/TA) and impaired renal function, and 30 sex- and age-matched WFG patients were enrolled in this study. The percentage of NK cell subsets including NK CD56bright and NK CD56dim cells were determined by flowcytometry; IL-2, IL-15, and IL-18 genes expressions were assessed by real-time PCR. RESULTS Compared to WFG patients, there was a significant (p<0.05) increase in the percentage of NK CD56bright cells in CAD patients. However, the difference in percentage of NK CD56dim cells or CD56dim/CD56bright ratio between the studied groups was not significant. In addition, IL-2, 15 and 18 genes expressions were almost similar in CAD and WFG patients. CONCLUSION We found higher percentages of NK CD56bright subset in kidney transplant recipients with CAD without considerable changes in related cytokines' gene expression, suggesting a possible defect of NK cells maturation in these patients.