Clinical Values of Elevated Serum Cytokeratin-18 Levels in Hepatitis: A Meta-Analysis

BACKGROUND As an important intermediate filament protein within liver cells, cytokeratin-18 (CK-18) has been confirmed as a potential indicator in various hepatitis progressions. OBJECTIVES We sought to clarify the connection between serum CK-18 levels and hepatitis pathogenesis in the present meta-analysis. MATERIALS AND METHODS With the application of various computerized databases, including PubMed, Embase, Cochrane Library, Google Scholar, Web of Science, China BioMedicine (CBM), China National Knowledge Infrastructure (CNKI), published papers that assessed the relationship between serum CK-18 levels and hepatitis were obtained. The main key words used are "Hepatitis", "hepatitides", "Cytokeratin-18", "Keratin-18" and "CK-18". Statistical analysis was conducted using the STATA software (version 12.0). RESULTS Eight case-control studies published between 2010 and 2014 were confirmed eligible, according to our selection criteria. The results of the meta-analysis showed that serum levels of CK-18 in hepatitis patients were higher compared to healthy controls (standardized mean difference (SMD) = 3.71, 95%CI: 2.27-5.14, P < 0.001). Subgroup analysis by ethnicity and disease implicated that high serum CK-18 levels might be a risk factor for non-alcoholic steatohepatitis (NASH), chronic hepatitis C (CHC), and chronic hepatitis B (CHB) (all P < 0.05) among Asians (SMD = 2.89, 95%CI: 2.35-3.43, P < 0.001), Africans (SMD = 0.69, 95%CI: 0.12-1.26, P = 0.017), and Caucasians (SMD = 4.86, 95%CI: 1.82-7.89, P = 0.002). CONCLUSIONS Serum CK-18 levels in hepatitis patients were higher, compared with healthy controls. Our results revealed the clinical values of CK-18, in combination with other apoptosis markers, in identifying the development of hepatitis.