Disentangling the lifespans of hepatitis C virus‐infected cells and intracellular vRNA replication‐complexes during direct‐acting anti‐viral therapy

Copyright © 2019 John Wiley & Sons Ltd.
© 2019 John Wiley & Sons Ltd
The decay rate of hepatitis C virus (HCV)-infected cells during therapy has been used to determine the duration of treatment needed to attain a sustained virologic response, but with direct-acting anti-virals (DAA), this rate has been difficult to estimate. Here, we show that it is possible to estimate it, by simultaneously analysing the viral load and alanine aminotransferase (ALT) kinetics during combination DAA therapy. We modelled the HCV RNA and ALT serum kinetics in 26 patients with chronic HCV genotype 1b infection, under four different sofosbuvir-based combination treatments. In all patients, ALT decayed exponentially to a set point in the normal range by 1-3 weeks after initiation of therapy. The model indicates that the ALT decay rate during the first few weeks after initiation of therapy reflects the death rate of infected cells, with an estimated median half-life of 2.5 days in this patient population. This information allows independent estimation of the rate of loss of intracellular replication complexes during therapy. Our model also predicts that the final ALT set point is not related to the release of ALT by dying HCV-infected cells. Using ALT data, one can separately obtain information about the rate of 'cure' of HCV-infected cells versus their rate of death, something not possible when analysing only HCV RNA data. This information can be used to compare the effects of different DAA combinations and to rationally evaluate their anti-viral effects.
Portions of this work were done under the auspices of the US Department of Energy under contract 89233218CNA000001. This research was supported by the National Science Foundation under grant no. NSF PHY11-25915; by NIH grants R25GM067110, R01AI028433, R01OD011095, R01AI078881, R01AI116868, and P30AI050409; Gordon and Betty Moore Foundation Grant no. 2919.01; Cheng Si-yuan (China-international) Hepatitis Research Foundation and Humanity & Health Medical group.