Author(s): Wang Y, Ye Z, Meng XQ, Zheng SS
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Abstract BACKGROUND: Human leukocyte antigen G (HLA-G) is a non-classical major histocompatibility complex class I molecule that has multiple immune regulatory functions including the induction of immune tolerance. The detection of HLA-G expression might serve as a clinical marker in the prediction of clinical outcomes for certain types of carcinoma. Currently, we investigated whether or not HLA-G is also expressed in patients with hepatocellular carcinoma (HCC), and whether the expression has clinical value. METHODS: Serum levels of secreted HLA-G (sHLA-G) were measured by ELISA in 36 patients with HCC, 25 patients with liver cirrhosis (LC) and 25 healthy individuals. The expression of HLA-G in liver tissue was further studied using Western blotting in 36 patients with HCC and 25 with LC. The correlations between HLA-G status and various clinicopathological parameters including survival were analyzed. RESULTS: The ELISA assay showed that the serum levels of sHLA-G in the HCC, LC and healthy groups were 132.6+/-31.4, 63.5+/-22.1, and 47.0+/-15.5 U/ml, respectively. Analysis of variance was used for inter-group comparison and differences were found between the HCC group and the other two groups (both P<0.01), while no difference was found between the LC group and the healthy group (P=0.112). HLA-G protein expression in liver tissue was found in 66.7\% (24/36) of the primary sites of HCC, but not in benign lesions (LC). Further, the HLA-G expression in tumors had no significant correlation with the parameters of age, gender, histological grade and alpha-fetoprotein level. However, patients with HLA-G-positive tumors had a shorter postoperative survival time than those with HLA-G-negative tumors (P=0.014). Also, univariate analysis showed that HLA-G was an independent prognostic factor. CONCLUSION: Our results indicated that the expression of HLA-G was a characteristic feature of HCC and patients with positive expression of HLA-G in malignant liver tissue had a poor prognosis.
This article was published in Hepatobiliary Pancreat Dis Int
and referenced in Journal of Clinical & Cellular Immunology