The clinical significance of serum soluble interleukin 2 receptor (sIL-2R) concentration in lung cancer

The activated mononuclear cells can release a soluble form of interleukin 2 receptor (sIL-2R) in the blood. Serum sIL-2R level is a sensitive and quantitative marker of circulating peripheral blood mononuclear cell activation. This molecule acts as an antagonist of IL-2- mediated responses. The present study was carried out to analyze the circulating levels of sIL-2R in lung cancer in relation to the histological type of the turnout, clinical stage, response to therapy, time survival for patients. The study included 62 patients (30 SCLC, 32 NSCLC) and 10 healthy subjects as controls. SIL-2R serum levels were measured with a sandwich enzyme immunoassay using commercial kits (ENDOGEN). The mean serum values of sIL-2R were significantly higher in cancer patients than in controls (p=0,01). There was no significant difference in relation to tumour histological type. Within the NSCLC chemotherapy group, sIL-2R mean levels observed at the end of chemotherapy were higher in the progressing patients than in the responding patients, The metastatic patients had higher levels of sIL-2R than those with locally limited disease. In the case of SCLC classified to extensive disease mean levels of sIL-2R were higher than SCLC classified to limited disease. The mean serum values of sIL-2R were significantly higher in weight loss patients than no weight ones (p=0,03). Within NSCLC group there was a correlation between sIL-2R mean levels and the age of patients (p=0,04). In SCLC group there was a correlation between levels of sIL-2R and time survival for patients (p=0,009).