Serum Levels of Cytokines and Soluble Cytokine Receptors in Patients with Metastatic Renal Cell Carcinoma or Malignant Melanoma Receiving IL-2/Interferon-α Combination Therapy

Abstract

Elevated serum levels of soluble tumour necrosis factor receptor (sTNFR-55) and (at a lesser degree) of sTNFR-75 were found in most of the patients with metastatic renal cell carcinoma (RCC) or malignant melanoma (MM) before immunotherapy and with further increase during treatment (intravenous infusions of interleukin-2 [IL-2] and subcutaneous interferon-α [IFN-α]). In the majority of the patients with MM the pretreatment serum levels of IL-2 and soluble IL-2 receptor (sIL-2R) were increased, whereas fewer patients with RCC presented with increased serum levels of IL-2 and sIL-2R. Twelve days' treatment with IL-2/IFN-α, with a rest on days 6 and 7, resulted in a consistent further increase in the serum levels of sIL-2R and sTNFRs. In most patients the increase of sIL-2R and sTNFRs lasted for at least 3 weeks after treatment discontinuation. The clinical significance of the increase remains unknown.