The Analysis of Mutual Relationship Between Hemostasis and Inflammatory Processes in Patients with Chronic Liver Diseases

Introduction: Monocytes play a crucial role in the pathogenesis of inflammation and fibrosis in chronic liver diseases (CLD). Platelet, by connecting hemostasis and inflammatory processes, also participate in the pathogenesis of CLD. We aimed to assess the expression of platelet monocyte aggregates and their relationship to both monocyte and platelet activation in patients with hepatitis C virus (HCV) induced CLD in relation to the degree of hepatic insufficiency and haemostatic imbalance.

Methods: Sixty patients with HCV induced CLD were categorized after Child Pugh criteria into 4 groups: Child A, B, C and C during acute attack of haematemesis, 15 patients each, 15 healthy subjects were also included as normal controls. Immunophenotype characterization for identification of platelet monocyte aggregates (CD41/CD45) on activated blood monocytes (CD11b and CD14) and activated blood platelet populations (CD61and CD62P) was carried out by flowcytometric analysis. The circulating levels of monocyte activation marker (MCP-1) and platelet activation markers (PF4 and sP-selectin) were also determined using immunological assays.

Results: A marked reduction in platelet count concomitant with a decrease in the CD61 platelets surface expression were noticed in different groups of patients with HCV (p<0.01) compared to healthy subjects, implicating that the platelet count drops in correlation with advancement of liver cirrhosis. Data demonstrated a significant increase (p<0.01) in the surface expression of each of CD11b, CD14 and CD41/45 on peripheral blood monocytes revealing increased monocyte activation in patients with HCV compared to controls, especially Child C groups. These findings revealed that the increased expression of CD11b on blood monocytes matches the advancement of liver failure and that the CD14 is up regulated in viral hepatitis and correlate with liver injury. MCP-1 concentration did not correlate with monocyte count in peripheral blood denoting that MCP-1 level did not reflect the inflammatory activity in patients with liver cirrhosis, as it was lower in blood serum than in healthy subjects. Moreover, a significant progressive increase (p<0.01) in the expression of CD62P and CD41/CD45 on platelets and in the circulating levels of sP-selectin and PF4 was also detected in different groups of patients with HCV compared to controls. These findings revealed increased platelet activation with the rise in population of CD62P phenotype in patients with liver cirrhosis despite thrombocytopenia intensification. Our results also showed that the CD62P platelet surface expression was inversely correlated with platelet count and was strongly correlated with sP-selectin levels in Child B and C groups. Likewise, PF4 levels were strongly correlated with CD62P platelet surface expression and inversely correlated with platelet count in both groups revealing that the more developed thrombocytopenia, the stronger the platelet activation in liver cirrhosis. Our data also demonstrate that CD41/45 surface expression of blood platelet monocyte aggregate on platelets and monocytes are inversely correlated with platelet count and strongly correlated with each of monocyte activation (CD11b and CD14) and platelet activation (sP-selectin, CD62P and PF4) markers in patients with Child B and C showing that as cirrhosis develops and platelet count diminishes platelet aggregations with monocytes increase.

Conclusions: Monocytes and platelets activation in patients with HCV increased in stepwise fashion in conjunction with worsening severity of liver disease as assessed by Child Pugh staging. The interplay of several factors such as endotoxaemia, lipopolysaccharides, oxidative stress and proinflammatory cytokines may be implicated in this respect. Also, the permanent flow of leukocytes and platelets through inflamed liver tissues and their long exposure to the active proinflammatory factors may lead to the activation of these cells. In turn, the progressive increase in monocytes and platelets activation with the simultaneous formation of monocyte-platelet aggregates noticed in patients with HCV may contribute to progressive liver injury in these patients.  We, therefore, suggest that the blockage of platelet and monocyte activation may diminish thrombocytopenia and liver cirrhosis intensification in patients with chronic hepatitis C virus.