Detection of Circulating Antibodies to p16 Protein-Derived Peptides in Hepatocellular Carcinoma

Yangchun Xu, MM; Litong Gu, MM; Jiaxin Wang, MD; Zhenqi Wang, MD; Ping Zhang, MD, PhD; Xuan Zhang, MD, PhD


Lab Med. 2020;51(6):574-578. 

In This Article


The in-house ELISA used in this study had a better repeatability (the comparison among the repeats), with a coefficient of variation of 15.2%, calculated based on the SBR (1.84 ± 0.28) from QC specimens tested independently in 13 plates. Anti-p16 IgG levels of HCC patients were obviously elevated compared with those of the controls (Z = 3.51, P = 0.0004). Anti-p16 IgG levels were significantly higher in both male (Z = 2.86, P = 0.004) and female (Z = 2.36, P = 0.018) patients than in the healthy controls, implying that plasma anti-p16 IgG levels were elevated in all HCC patients, regardless of sex (Table 2).

Further analysis of the association between plasma anti-p16 IgG levels and clinical stages revealed that plasma anti-p16 IgG levels displayed an increasing trend with HCC stages (Table 3), with group 3 (stages C + D) patients having the highest anti-p16 IgG levels (Z = 3.38, P = 0.0008). However, there was no obvious correlation (Z = 0.97, P = 0.331) between anti-p16 IgG levels and clinical stages in group 1 (stages 0 + A) patients.

An AUC of 0.622 (95% CI, 0.554–0.690) was obtained for all HCC patients, based on the ROC curve analysis, with a sensitivity of 11.4% and a specificity of 95% (Table 3). As shown in Table 4, of the 3 groups of HCC patients, group 3 (stages C + D) showed the best sensitivity for plasma anti-p16 IgG level detection, with an AUC of 0.659 (95% CI, 0.564–0.754), followed by group 2 (stage B), with an AUC of 0.623 (95% CI, 0.531–0.717). The AUC for group 1 (stages 0 + A) patients was 0.562 (95% CI, 0.442–0.680), with a sensitivity of 0, suggesting the potential use of plasma anti-p16 IgG as a more biomarker for HCC prognosis, compared to early HCC diagnosis.