Lymphocyte release of soluble IL-2 receptors in patients with minimal change nephropathy.

Minimal change nephrotic syndrome has been reported to be a lymphocyte-mediated disorder. It has been suggested that the secretion of lymphokine(s) is involved in the pathogenesis of MCN and in determining proteinuria. The presence of a soluble form of IL-2 receptor (sIL-2R) has been previously described in the sera of patients with some autoimmune disorders. In this work, we report the detection of high sIL-2R levels, both in the plasma (mean value 844 +/- 436 U/ml versus normal value 276 +/- 86 U/ml) and urine of patients with MCN during the nephrotic phase alone. Instead, when the patients achieve stable remission, sIL-2R levels decrease to within normal values (mean value 332 +/- 272 U/ml). Furthermore, during the nephrotic syndrome we observed a significant inverse relationship between sIL-2R plasma levels and the mitogenic response to PHA (p less than 0.005). Since sIL-2R exerts a down-modulation on T-proliferative expansion, sIL-2R might represent one of the inhibitory serum factors extensively reported in the serum of patients with MCN-induced nephrotic syndrome.