Oxidative Stress Mediates a Reduced Expression of the Activating Receptor NKG2D in NK Cells from End-Stage Renal Disease Patients

To characterize the immune defect of patients with end-stage renal disease (ESRD), we performed NK cell subset analysis in 66 patients with ESRD treated by hemodialysis ( n = 59) or peritoneal dialysis ( n = 7). Compared with healthy blood donors, patients undergoing chronic dialysis showed a profound decrease in NKG2D + cells within both the CD8 + T cell (58% vs 67%, p = 0.03) and NK cell (39% vs 56%, p = 0.002) populations. CD56 dim cells, which comprise the majority of NK cells in the periphery, were more affected in this regard than were CD56 bright cells. Uremic serum could decrease NKG2D expression on NK cells from healthy donors. Among factors that could contribute to the decrease in NKG2D expression in ESRD patients, reactive oxygen species (ROS) play a major role. We found that catalase could reverse the effects of uremic serum on NKG2D expression ( p p = 0.04) and increased soluble MICA (203 pg/ml vs 110 pg/ml; p