HEMODIALYSIS-RELATED INTERLEUKIN-2 RECEPTOR RELEASE BY PERIPHERAL-BLOOD MONONUCLEAR-CELLS

To evaluate the effects of hemodialysis treatment on the spontaneous c ell release of interleukin-2 receptor (IL-2R), we studied 19 hemodialy zed patients (HD), 9 non hemodialyzed patients with chronic uremia (UR , glomerular filtration rate: 8.4 +/- 1.8 ml/min), and 8 healthy contr ol subjects (C). We measured the release of IL-2R in the supernatant o f peripheral blood mononuclear cells (PBMC) cultured for 24 hrs in Isc ove's medium as well as the plasma levels of IL-2R. A significant incr ease of IL-2R release was detected in the supernatant of PBMC harveste d from HD patients (32.4 +/- 2.4 and 34.2 +/- 5.6 U/3 X 10(6) PBMC dai ly before and after HD, respectively) as compared with UR (16.6 +/- 5. 2 U/3 X 10(6) PBMC daily) and C (21.4 +/- 3.8 U/3 X 10(6) PBMC daily). Similarly, IL-2R plasma levels were significantly higher in HD (378.5 +/- 164.6 U/ml) than in Up (189.5 +/- 89.3 U/ml) and C (11.2 +/- 2.68 U/ml). To summarize, the current study demonstrates: a) an enhancemen t of spontaneous IL-2R cell release in HD patients; b) an increase of sIL-2R plasma levels in tip patients possibly related to reduced metab olism and/or urinary excretion, because it was not associated with hig h IL-2R cell release; and c) a further increment of IL-2R systemic lev els in HD likely secondary to the high cell release of IL-2R. Therefor e, a chronic T cell activation with increased release of IL-2R seconda ry to the dialysis procedure is suggested.