INCREASED IL-2, IL-4 AND INTERFERON-GAMMA (IFN-GAMMA) IN STEROID-SENSITIVE NEPHROTIC SYNDROME

We investigated the production of cytokines by peripheral blood mononu clear cells (PBMC) and serum cytokine concentrations in children with steroid-sensitive idiopathic nephrotic syndrome (SSNS). PBMC from pati ents off treatment were collected during remission and relapse and cul tured in medium alone or stimulated with calcium ionophore plus phorbo l myristate acetate. Control PBMC were taken from healthy age-matched children. IL-2 was measured by bioassay, IL-4 by immunoradiometric ass ay, and IL-8 and IFN-gamma by ELISA. After 24 h culture without stimul ation, IL-2, IL-4 and IFN-gamma were not detectable in the supernatant in any of the children. After stimulation, the supernatant concentrat ions of IL-2 (median 172 U/ml at 24 h) and IL-4 (160 pg/ml at 24 h; 21 0 pg/ml at 72 h) were significantly increased in relapse compared with remission (IL-2 37 U/ml; IL-4 65 pg/ml and 60 pg/ml) and controls (IL -2 69 U/ml; IL-4 40 pg/ml and 40 pg/ml) (P < 0.05). The concentration of IFN-gamma was not significantly increased in relapse compared with remission and controls (600, 325, and 145 U/ml, respectively, at 72 h) . IL-8 concentrations were similar in relapse, remission and controls with stimulation (median 32, 40 and 40 ng/ml, respectively) and withou t (30, 17 and 10 ng/ml). IL-2 was not detectable in serum, but IL-4, I L-8 and IFN-gamma were measurable in about half the patients, both in relapse and remission, though were virtually undetectable in controls. We conclude that relapse of SSNS in children is associated with T lym phocyte activation with release of IL-2, IL-4 and IFN-gamma.