Plasma levels of growth-related oncogene (CXCL1-3) associated with fibrosis and platelet counts in HCV-infected patients

BackgroundFibrosis progression in hepatitis C virus (HCV)-infected patients varies greatly between individuals. Chemokines recruit immune cells to the infected liver and may thus play a role in the fibrosis process. AimTo investigate plasma levels of a diverse chemokine panel in relation to liver fibrosis. MethodsAfrican-American and Caucasian HCV genotype 1 infected patients were treated with peginterferon (pegIFN) and ribavirin (RBV) for 48weeks (VIRAHEP-C cohort). Plasma levels of 13 cytokines were studied at baseline (n=386). Subsequently, GRO levels were assessed in a sub cohort (n=99) at baseline, and at 4 and 12weeks after start of pegIFN/RBV treatment. ResultsIncreased severity of fibrosis (Ishak fibrosis score 0-2 vs. 3-6) was associated with increased plasma IP-10 (CXCL10) and IL-8 (CXCL8) levels, and decreased plasma levels of the chemokine growth-related oncogene (GRO, CXCL1-3). Plasma GRO levels were also positively correlated with platelet counts, and were higher in African-American as compared to Caucasian patients. In response to pegIFN/RBV treatment, GRO levels increased in Caucasian but not African-American patients from week 4 onwards. ConclusionsThe association with severity of fibrosis and platelet count positions plasma GRO as a potential biomarker for liver fibrosis in HCV-infected patients. The secretion of GRO by platelets may explain the correlation between GRO plasma level and platelet count. The ethnic difference in GRO levels both pre-treatment and in response to pegIFN/RBV might be driven by a genetic polymorphism in GRO associated with higher plasma levels and more common in the African-American population.