Type-I interferon receptor expression: Its circadian rhythm and downregulation after interferon-α administration in peripheral blood cells from renal cancer patients

Objectives: To investigate the regulation of interferon‐α (IFN‐α) receptor expression in metastatic renal cell carcinoma (RCC) after IFN‐α administration. Methods: Blood sampling was carried out in eight patients with metastatic RCC and six healthy volunteers. Flow‐cytometric analysis using a monoclonal antibody against the active subunit of the type‐I IFN‐α receptor (IFNAR2) was carried out to examine the circadian rhythm of IFNAR2 expression in peripheral blood mononuclear cells (PBMC) as well as its downregulation after IFN‐α administration. Results: According to its circadian rhythm IFNAR2 in PBMC had a peak expression at night. Once IFN‐α is administered, IFNAR2 levels in PBMC showed downregulation within 48 h and recovered within another 48 h. Conclusions: Our findings might support the establishment of an optimal schedule for IFN‐α administration.