Detection of Interleukin-33 in Serum and Carcinoma Tissue from Patients with Hepatocellular Carcinoma and its Clinical Implications

OBJECTIVE: To study the clinical significance of intercellular interleukin (IL)-33 in hepatocellular carcinoma (HCC). METHODS: Using immunohistochemistry, this prospective study compared IL-33 protein levels in samples of HCC tissue and normal tissue adjacent to the tumour in 60 patients with HCC, and in normal liver tissue from six healthy controls. Interferon (IFN)-α, IFN-γ and IL-33 serum levels were also analysed by enzyme-linked immunosorbent assay in HCC 30 patients and 10 healthy controls. The level of IL-33 immunohistochemical staining was compared with the rate of lymph node metastasis in HCC patients. RESULTS: IL-33 was strongly positive in the cytoplasm of hepatocytes. The median percentage of IL-33-positive tissue was higher in HCC than in normal liver tissue samples (adjacent to the tumour or from controls). Serum IFN-α, IFN-γ and IL-33 levels were higher in pre- and postoperative samples from HCC patients than in control samples, and in patients with metastasis compared with those without metastasis. CONCLUSIONS: Increased IL-33 protein levels were observed in serum and liver tissue from HCC patients; IL-33 may be a useful biological marker for monitoring HCC growth and metastasis.