Hemodialysis Related lnterleukin-2 Receptor Release by Peripheral Blood Mononuclear Cells

To evaluate the effects of hemodialysis treatment on the spontaneous cell release of interleukin-2 receptor (IL-2R), we studied 19 hemodialyzed patients (HD), 9 non hemodialyzed patients with chronic uremia (UR, glomerular filtration rate: 8.4 ± 1.8 ml/min), arid 8 healthy control subjects (C). We measured the release of IL-2R in the supernatant of peripheral blood mononuclear cells (PBMC) cultured for 24 hrs in Iscove's medium as well as the plasma levels of IL-2R. A significant increase of IL-2R release was detected in the supernatant of PBMC harvested from HD patients (32.4 ± 2.4 and 34.2 ± 5.6 U/3 × 10⁶ PBMC daily before and after HD, respectively) as compared with UR (16.6 ± 5.2 U/3 × 10⁶ PBMC daily) and C (21.4 ± 3.8 U/3 × 10⁶ PBMC daily). Similarly, IL-2R plasma levels were significantly higher in HD (378.5 ± 164.6 U/ml) than in UR (189.5 ± 89.3 U/ml) and C (11.2 ± 2.68 U/ml). To summarize, the current study demonstrates: a) an enhancement of spontaneous IL-2R cell release in HD patients; b) an increase of slL-2R plasma levels in UR patients possibly related to reduced metabolism and/ or urinary excretion, because it was not associated with high IL-2R cell release; and c) a further increment of IL-2R systemic levels in HD likely secondary to the high cell release of IL-2R. Therefore, a chronic T cell activation with increased release of IL-2R secondary to the dialysis procedure is suggested.