Rate of hepatitis C viral clearance by human livers in human patients: Liver transplantation modeling primary infection and implications for studying entry inhibition

Modeling hepatitis C virus kinetics during liver transplantation reveals the role of the liver in virus clearance

While the liver, specifically hepatocytes, are widely accepted as the main source of hepatitis C virus (HCV) production, the role of the liver/hepatocytes in clearance of circulating HCV remains unknown. Frequent HCV kinetic data were recorded and mathematically modeled from five liver transplant patients throughout the anhepatic (absence of liver) phase and for 4 hr post-reperfusion. During the anhepatic phase, HCV remained at pre-anhepatic levels (n = 3) or declined (n = 2) with t_1/2~1 hr. Immediately post-reperfusion, virus declined in a biphasic manner in four patients consisting of a rapid decline (t_1/2 = 5 min) followed by a slower decline (t_1/2 = 67 min). Consistent with the majority of patients in the anhepatic phase, when we monitored HCV clearance at 37°C from culture medium in the absence/presence of chronically infected hepatoma cells that were inhibited from secreting HCV, the HCV t_1/2 in cell culture was longer in the absence of chronically HCV-infected cells. The results suggest that the liver plays a major role in the clearance of circulating HCV and that hepatocytes may be involved.

Safety and Efficacy of Avaren-Fc Lectibody Targeting HCV High-Mannose Glycans in a Human Liver Chimeric Mouse Model

BACKGROUND & AIMS

Infection with hepatitis C virus (HCV) remains a major cause of morbidity and mortality worldwide despite the recent advent of highly effective direct-acting antivirals. The envelope glycoproteins of HCV are heavily glycosylated with a high proportion of high-mannose glycans (HMGs), which serve as a shield against neutralizing antibodies and assist in the interaction with cell-entry receptors. However, there is no approved therapeutic targeting this potentially druggable biomarker.

METHODS

The anti-HCV activity of a fusion protein consisting of Avaren lectin and the fragment crystallizable (Fc) region of a human immunoglobulin G1 antibody, Avaren-Fc (AvFc) was evaluated through the use of in vitro neutralization assays as well as an in vivo challenge in a chimeric human liver (PXB) mouse model. Drug toxicity was assessed by histopathology, serum alanine aminotransferase, and mouse body weights.

RESULTS

AvFc was capable of neutralizing cell culture-derived HCV in a genotype-independent manner, with 50% inhibitory concentration values in the low nanomolar range. Systemic administration of AvFc in a histidine-based buffer was well tolerated; after 11 doses every other day at 25 mg/kg there were no significant changes in body or liver weights or in blood human albumin or serum alanine aminotransferase activity. Gross necropsy and liver pathology confirmed the lack of toxicity. This regimen successfully prevented genotype 1a HCV infection in all animals, although an AvFc mutant lacking HMG binding activity failed.

CONCLUSIONS

These results suggest that targeting envelope HMGs is a promising therapeutic approach against HCV infection, and AvFc may provide a safe and efficacious means to prevent recurrent infection upon liver transplantation in HCV-related end-stage liver disease patients.

Bioinformatics Analysis of Quantitative PCR and Reverse Transcription PCR in Detecting HCV RNA

Objective:

This research aimed to make comparisons of sensitivity and specificity between Quantitative real Time Polymerase Chain Reaction (Q-PCR) and Reverse Transcription PCR (RT-PCR) in detecting the ribonucleic acid (RNA) expression levels of Hepatitis C Virus (HCV).

Methods:

121 patients suffering from hepatitis C and 98 healthy participants with normal liver functions were identified. The venous blood collections were carried out, were subjected to detect the expression levels of HCV RNA via Q-PCR and RT-PCR. And then, the data obtained from these above two detection methods were compared, including the sensitivity and specificity.

Results:

In terms of Q-PCR, the positive rate of HCV RNA was 72.16%, which was significantly higher when compared with 55.26% of RT-PCR. After statistical analysis, the difference between them was statistically significant (P＜0.05). Among the healthy participants, 4 cases were false positive by means of RT-PCR, there was the possibility of missed diagnosis when the samples were evaluated by Q-PCR.

Conclusion:

: The Q-PCR detection technology performed well in testing HCV, with pretty high sensitivity and specificity. Nevertheless, the false negative results obtained from Q-PCR could not be avoided. In clinical practice, these above two detection methods should be referred to, in order to avoid missed diagnosis.