Markers of liver fibrosis and apoptosis in patients with HIV mono-infection and HIV/HCV co-infection

Introduction
Human immunodeficiency virus (HIV)/hepatits C virus (HCV) co-infection has a significant impact on liver-related morbidity and mortality. Among many other pathogenic mechanisms leading to accelerated hepatic disease are liver fibrosis and hepatocyte apoptosis. Hence the objective of this investigator-initiated cross-sectional study was to analyse the plasma levels of hyaluronic acid, cytokeratin-18, and cytochrome c in order to assess their impact on progression of liver disease in patients with HIV/HCV co-infection comparing to those with HIV mono-infection.

Material and methods
There were 80 patients with HIV infection included in the study. HCV co-infection was in 46 (57.5%) patients and HIV mono-infection in 34 patients. Blood levels of hyaluronic acid were tested using a Hyaluronic Acid test Kit, cytokeratin-18 neoepitope levels using M30-Apoptose ELISA test, and cytochrome c using human Cytochrome c ELISA test.

Results
The levels of cytokeratin-18 and of hyaluronic acid were significantly higher in the group of patients with HIV/HCV co-infection. The differences in the level of cytochrome c were not significant. The analysis revealed that the main effect of HCV co-infection on the level of cytokeratine-18 is indirect. It is mediated by the level of hyaluronic acid.

Conclusions
The progression of liver disease in patients with HIV/HCV co-infection is more pronounced compared to those with HIV mono-infection. It is shown by the higher plasma levels of hyaluronic acid, which is a relevant liver fibrosis marker and hepatocyte apoptosis marker cytokeratin-18 in patients with HIV/HCV co-infection. The hyaluronic acid level is important in assessing the impact of HCV co-infection on liver apoptosis.