Decrease in cholesterol levels during the immunotherapy of cancer with interleukin-2.
IL-2, in addition to its immunomodulating and antitumour properties, induces important systemic actions, including cardiovascular, neuroendocrine and metabolic effects. The present study was carried out to evaluate IL-2 effects on cholesterol metabolism. The study included 14 advanced cancer patients (renal carcinoma: ten; colon carcinoma: four), who received IL-2 subcutaneously at a dose of 1.8 x 10(6) IU ml-2 twice daily for 5 days/week for 6 weeks. Venous blood samples were collected 7 days before, on days 0, 3, 7, 14, 21, 42 of IL-2 therapy, and on days 14 and 28 of the rest-period. IL-2 induced a rapid and evident decrease in cholesterol levels, with a normalisation of its concentrations within 7 days in 10/10 hypercholesterolemic patients. The lowest mean levels of cholesterol were reached within the first 2 weeks; after that they still slowly increased. LDL-/HDL-cholesterol ratio was significantly reduced by IL-2 therapy. Cholesterol fall was associated with a marked increase in conjugated biliary acid levels. Finally, triglyceride values increased during IL-2 therapy, but not in a significant manner. These results, by showing that IL-2 exerts an evident and very rapid cholesterol-lowering activity, would represent a further demonstration of the physiological importance of cytokines in the control of cholesterol metabolism.