Acute endocrine effects of interleukin-12 in cancer patients

IL-12, which play a fundamental antitumor role, would be also involved in the physiological regulation of neuroendocrine and immune interactions. At present, however, there are no data about the endocrine effects of IL-12. This preliminary study was performed to investigate the acute endocrine effects of IL-12 in metastatic renal cell cancer patients. Each IL-12 injection consisted of 0.5 micrograms/kg/bw subcutaneously in the morning. The study has evaluated the effects of 6 different injection cycles. Serum samples were collected before, and 4, 8 and 12 hours from IL-12 injection. In each sample, we have measured by the RIA method serum levels of GH, PRL, TSH, FSH, LH, T3, T4, cortisol, testoterone, estradiol and the pineal hormone melatonin. No significant change occurred in TSH, FSH, LH, T3, T4, testoterone and melatonin mean serum levels in response to IL-12 administration. In contrast, cortisol, PRL and estradiol significantly increased after Il-12 injection. GH also increased in response to IL-12, without however, significant differences with respect to the baseline values. This preliminary study shows that the acute subcutaneous injection of IL-12 may influence the endocrine secretions in humans. In particular, IL-12 would stimulate the secretions of cortisol, PRL and estradiol. Therefore, this study would further confirm that IL-12 may act as biological response modifier in humans, not only on the immune system, but also on the neuroendocrine functions.