Macrophage-related serum biomarkers soluble CD163 (sCD163) and soluble mannose receptor (sMR) to differentiate mild liver fibrosis from cirrhosis in patients with chronic hepatitis C: a pilot study

Macrophages regulate the fibrotic process in chronic liver disease. The aim of the present pilot study was to evaluate two new macrophage-specific serum biomarkers [soluble CD163 (sCD163) and soluble mannose receptor (sMR, sCD206)] as potential fibrosis markers in patients chronically infected with hepatitis C virus (HCV). Forty patients with chronic hepatitis C were included from two hospital clinics. On the day of inclusion, transient elastography (TE) was performed to assess the fibrosis stage, and blood samples were collected for the measurement of sCD163 and sMR. The plasma concentrations of both biomarkers were significantly higher in patients infected with HCV and with cirrhosis compared to those with no/mild liver fibrosis (5.77 mg/l vs. 2.49 mg/l and 0.44 mg/l vs. 0.30 mg/l for sCD163 and sMR, respectively). The best separation between groups was obtained by sCD163 [area under the receiver operating characteristic curve (AUC) 0.89 (95 % confidence interval [CI] 0.79-0.99)] as compared to sMR [AUC 0.75 (95 % CI 0.61-0.90)]. sCD163 and sMR correlated significantly (r (2) = 0.53, p < 0.0001). Interestingly, sCD163 also correlated significantly with TNF-alpha (presented in a previous publication), which is shed to serum by the same mechanism as sCD163 (r (2) = 0.40, p < 0.0001). In conclusion, the macrophage-related markers sCD163 and sMR are significantly higher in patients chronically infected with HCV and with cirrhosis than in those with no/mild fibrosis. sCD163 is a promising new fibrosis marker in patients infected with HCV.