Change of circulating antibodies against CD25-derived peptide antigen in hepatocellular carcinoma.

Aims: Several studies have shown altered levels of plasma anti-CD25 antibodies in patients with malignancy in lung, esophagus and breast. The present study was thus designed to test whether circulating anti-CD25 antibody levels were changed in hepatocellular carcinoma (HCC). Methods: An enzyme-linked immunosorbent assay (ELISA) was developed in-house to detect plasma IgG antibodies to CD25-derived linear peptide antigens in 122 patients with HCC and 121 control subjects. Results: Student's t-test showed that plasma anti-CD25 IgG levels were significantly higher in HCC patients than control subjects (t = 4.96, P < 0.001), in which male patients mainly contributed to the increased IgG levels (t = 5.11, P < 0.001). Further analysis showed that plasma anti-CD25 IgG levels were dependent on the stages of HCC although there was no significant correlation between plasma anti-CD25 IgG levels and BCLC stages (r = 0.145, P = 0.110, N = 122); a significant increase in anti-CD25 IgG levels was observed in HCC patients with stages B (t = 4.43, P < 0.001) and C+D (t = 4.89, P < 0.001) as compared with control subjects. Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve (AUC) was 0.66 (SE = 0.035, 95% CI 0.60-0.73). The sensitivity of anti-CD25 IgG assay was 12.3% against a specificity of 99.2%. Conclusions: The present study suggests that circulating anti-CD25 IgG antibodies may have prognostic rather than early diagnostic values for HCC.