Gene expression profiles associated with anaemia and ITPA genotypes in patients with chronic hepatitis C (CH-C).

Anaemia is a common side effect of ribavirin (RBV) which is used for the treatment of hepatitis C. Inosine triphosphatase gene polymorphism (C to A) protects against RBV-induced anaemia. The aim of our study was to genotype patients for inosine triphosphatase gene polymorphism rs1127354 SNP (CC or CA) and associate treatment-induced anaemia with gene expression profile and genotypes. We used 67 hepatitis C patients with available gene expression, clinical, laboratory data and whole-blood samples. Whole blood was used to determine inosine triphosphatase gene polymorphism rs1127354 genotypes (CC or CA). The cohort with inosine triphosphatase gene polymorphism CA genotype revealed a distinct pattern of protection against anaemia and a lower drop in haemoglobin. A variation in the propensity of CC carriers to develop anaemia prompted us to look for additional predictors of anaemia during pegylated interferon (PEG-IFN) and RBV. Pretreatment blood samples of patients receiving a full course of PEG-IFN and RBV were used to assess expression of 153 genes previously implicated in host response to viral infections. The gene expression data were analysed according to presence of anaemia and inosine triphosphatase gene polymorphism genotypes. Thirty-six genes were associated with treatment-related anaemia, six of which are involved in the response to hypoxia pathway (HIF1A, AIF1, RHOC, PTEN, LCK and PDGFB). There was a substantial overlap between sustained virological response (SVR)-predicting and anaemia-related genes; however, of the nine JAK-STAT pathway-related genes associated with SVR, none were implicated in anaemia. These observations exclude the direct involvement of antiviral response in the development of anaemia associated with PEG-IFN and RBV treatment, whereas another, distinct component within the SVR-associated gene expression response may predict anaemia. We have identified baseline gene expression signatures associated with RBV-induced anaemia and identified its functional pathways. In particular, we identified the hypoxia response pathway and the apoptosis/survival-related gene network, as differentially expressed in chronic hepatitis C patients with anaemia.