Detection of Interleukins 6 and 18 Circulating Levels in Patients with Brain Tumors

The balance between T helper type 1 (Th1) and Th2 cytokines is thought to have an important role in simplified chaos of tumor progression. So we aimed to evaluate both IL-18 and IL-6 (pro-inflammatory cytokines for Th1 and trigger the Th2 cytokine release, respectively) in patients with brain tumors. In present case- control study serum samples were collected from 65 newly diagnosed patients with brain tumor and also 40 ones as control from normal population that were matched about their age and sex. Then the patients were divided into various groups according to pathologic reports of tumor type and median serum level of the cytokines determined by ELISA technique for each tumor types. Two major groups of malignant tumors (N=33) and benign tumors (N=32) was compared by nonparametric test of Kruskal-Wallis. There was significant increase in serum IL-6 level in malignant group (p< 0.01), while IL-18 was reduced in this group (p< 0.05). Acoustic schowanoma patients (N=13) divided into 2 groups, one with involvement of facial nerve (N=8) and another without this complication (N=5). We found IL-6 serum level was higher in complicated patients than the remained patients (p< 0.01). We concluded that the patients with more invasive and advanced brain tumors had more circulating levels of IL-6 in association of lower levels of IL-18, that present the immune balance due to humoral immunity in brain tumors is polarized in favor of Th2.