Platelet Microparticles and Monocyte Platelet Aggregates: Crucial Components of Chronic Hepatitis C Pathway

We aimed to clarify the impact of platelets microparticles (PMP) and monocyte platelet aggregates (MPA) interactions as aetiological factors of liver fibrosis in patients with chronic hepatitis C. Forty five patients were the subjects of the study, classified according to Child Pugh classification into; Child A, B and C groups (15 patients each), in addition to 15 matched controls. Flowcytometry was used for assessment of Platelet activation by quantitative assay of CD62P and CD63 PMPs and percentage of MPA. Liver fibrosis was assessed by both quantitative serum assay of monocyte chemoattractant protein-1 (MCP-1), matrix metaloproteinase-1 (MMP-1) and tissue inhibitor of matrix metaloproteinase-1 (TIMP-1) by ELISA technique, as well as immunohistochemical assay of MMP-1 and TIMP-1 in liver tissue. Enhanced platelet activation was demonstrated by increased PMP and PMA in different patients' groups and was more evident in advanced stages of the disease. Serum fibrosis markers revealed high MMP-1 and low levels of both TIMP-1 and MCP-1. Immunostaining showed increased positivity of MMP-1 with necroinflammtory activity and advancement of fibrosis. Also, immunostaining of TIMP-1 showed decrease in the number of positive cases as well as decrease in the intensity with advancement of fibrosis. Platelet activation markers showed a significant negative correlation with serum MMP-1 and positive correlation with serum TIMP-1. On the other hand, it showed a positive correlation with tissue immunostaining for both MMP-1 and TIMP-1. The above mentioned data are suggestive of a crucial role of platelet activation in the pathway of liver fibrosis.