Screening Of Serum Markers For Antiviral Therapy Of Hepatitis C Virus

Part 1Background and Aim The liver-specific microRNA-122 has been proved to be crucial for efficient replication of HCV RNA in vitro. Pretreatment intrahepatic levels of microRNA-122 in CHC patients may be related to the outcome of IFN therapy. Here we compared the serum levels of microRNA-122 in CHC patients and healthy donors by absolute quantification approach and evaluated its correlation with liver inflammation grades and serum ALT levels. MicroRNA microarray analysis was performed to screen serum microRNA candidates for predicting SVR in CHC patients undergoing peginterfron-based therapy.Methods Serum samples were collected from 105 untreated CHC patients and 33 healthy donors. Histological grades of liver inflammation were assessed using Ishak scoring system. Serum RNA was extracted using the mirVana PARIS (Ambion) protocol. Serum levels of microRNA-122 were measured using TaqMan RT-qPCR Assays. The Ct values were converted to copy numbers per microliter by drawing a standard curve of micoRNA-122 using chemically synthetic standard. To get the absolute quantification results, the copy numbers were normalized according the recovery ratios of the spiked-in cel-mir-39, which has been added to the sera before RNA extraction.Results Absolute quantification results showed that circulating levels of microRNA-122 were significantly higher in CHC patients than those in healthy donors (p<0.001). However, further statistical analysis found that there was no significant correlation between the serum levels of microRNA-122 and ALT. the same result was obtained when compared with liver inflammation grades. Levels of microRNA-221 and microRNA-603 were significantly different between CHC patients with SVR and non-SVR to peginterferon-based treatment.Conclusions The present study showed that serum microRNA-122 was elevated in untreated CHC patients. However, this biomarker for acute liver injury could not reflect the liver inflammation activity in chronic hepatitis C cases. MicroRNA-221 and microRNA-603 might be predictable for SVR in CHC patients.Part 2Background & Aims:IP-10 serum level has been shown be associated with viral response in chronic hepatitis C (CHC) patients. However, little is known for its role in Chinese population. Here we determined the IP-10 serum levels in Chinese CHC patients undergoing peginterferon-based therapy. Predictive value of IP-10 level for sustained virological response (SVR) was accessed.Methods:IP-10 serum levels were determined by ELISA in 165 HCV genotype 1 and 33 genotype 2 patients. Multivariate analysis was performed to screen independent factors for SVR prediction. Predictive value of IP-10 level in combination with IL28B genotype or rapid virological response (RVR) was further investigated.Results:Pretreatment IP-10 level was significantly higher in HCV genotype 1 patients and correlated with ALT level, however, was not associated with IL28B rs 12979860 genotypes or viral loads. IP-10 serum levels were independently predictive for SVR with cut-off values of 250.60 pg/ml at baseline and 407.40pg/ml at week 4. Positive predictive value (PPV) for SVR of IP-10 level less than 250.60 pg/ml at baseline and IL28B CC genotype was 96.15% and negative predictive value (NPV) was 50.00%. PPV for SVR of IP-10 level less than 407.40 pg/ml at week 4 and RVR was 95.24% and NPV was 50.00%.Conclusions:Pretreatment IP-10 serum levels were significantly higher in patients with HCV genotype 1 than genotype 2. IP-10 levels at baseline and week 4 were both predictable for SVR. Combination of IP-10 levels significantly improved the predictive performance of IL28B genotype or RVR for SVR in Chinese CHC patients.