Inflammatory cytokines and S-100b protein in patients with hepatitis C infection and cryoglobulinemias

Objective: To investigate a predictive role for the protein S-100b and serum circulating levels of Th1/Th2 cytokines in patients with chronic hepatitis C virus (HCV) infection with and without mixed cryoglobulinemia (MC). Methods: Sixty chronically HCV-infected patients were divided into two groups: 30 with and 30 without MC. Patients with MC presented detectable mixed cryoglobulins and clinical weakness, purpura and arthralgias. HCV-RNA and genotype, serum levels of cryoglobulins, principal hepatic indexes and levels of IL-6, IL-18 and S-100b protein were evaluated. Twenty uninfected healthy subjects were a control group to evaluate serum levels of S-100b protein. Results: IL-6 and IL-18 serum levels were higher in the MC+ group than the MC- group (8.7 ± 4.5 pg/mL versus 4.6 ± 2.3 pg/mL P < 0.0001 and 743.5 ± 128.2 pg/mL versus 578.5 ± 296.5 pg/mL P < 0.001 respectively). S-100b serum levels were higher in HCV+ with MC (0.23 ± 0.07 microg/L) respect to HCV+ patients without MC (0.17 ± 0.05 microg/L, P < 0.0001) and were statistically higher than in the control group (0.08 ± 0.03 microg/L, P < 0.0001 and P < 0.0001, respectively). A positive correlation was shown between serum levels of S-100b protein and levels of cryoglobulins in the group of HCV+ patients MC+ (r=0.72 and P < 0.0001). Conclusion: HCV patients with MC have a worse inflammatory condition than those without MC. Moreover, S-100b protein seems to be a sensitive marker of endothelial and tissue damage in chronic HCV hepatitis with cryoglobulinemia.