Second-Phase Hepatitis C Plasma Viral Kinetics Directly Reflects Reduced Intrahepatic Burden of Hepatitis C Virus.

BACKGROUND: Mathematical models explain how antivirals control viral infections. Hepatitis C virus (HCV) treatment results in at least 2 phases of decline in viremia. The first phase reflects clearance of rapidly produced virions. The second phase is hypothesized to derive from loss of infected cells but has been challenging to prove. METHODS: Using single-cell methods, we quantified the number of hepatitis C virus (HCV)-infected hepatocytes in liver biopsies taken before and within 7 days of initiating direct-acting antivirals (DAAs) in a double-blinded randomized controlled trial testing 2 (sofosbuvir-velpatasvir) versus 3 (sofosbuvir-velpatasvir-voxilaprevir) DAAs. RESULTS: We employed thousands of intrahepatic measurements in 10 persons with chronic genotype 1a HCV infection: median proportion of infected hepatocytes declined from 11.3% (range, 1.3%-59%) to 0.6% (range, <0.3%-5.8%), a loss of 75%-95% infected hepatocytes. Plasma viremia correlated with numbers of HCV-infected hepatocytes (r = 0.77; P < .0001). Second-phase plasma dynamics and changes in infected hepatocytes were indistinct (P = .16), demonstrating that second-phase viral dynamics derive from loss of infected cells. DAAs led to a decline in intracellular HCV RNA and interferon-stimulated gene expression (P < .05 for both). CONCLUSIONS: We proved that second-phase viral dynamics reflect decay of intrahepatic burden of HCV, partly due to clearance of HCV RNA from hepatocytes. CLINICAL TRIALS REGISTRATION: NCT02938013.

Preventing intrahepatic infection after ablation of liver tumours in biliary-enteric anastomosis patients.

PURPOSE: To assess the value of bowel preparation plus targeted antibiotics for preventing intrahepatic infections after MWA of liver tumours in BEA patients. MATERIALS AND METHODS: This retrospective study included 21 patients (divided into two groups) with a history of BEA undergoing ultrasound-guided MWA of liver tumours from November 2008 to June 2014. Group A (n = 10) received single-antibiotic therapy (cefazedone 2 g bid 4, amoxicillin and flucloxacillin sodium 2 g bid 3, levofloxacin 0.5 g qd 3) after ablation, and group B (n = 11) received bowel preparation before ablation plus combined antibiotic therapy (imipenem and cilastatin sodium 1 g 1/12 h, linezolid 0.6 g 1/12 h). Patients were followed for 3 months. Incidences of fever, bacteraemia, and intrahepatic infections were compared, including the duration of fever and length of hospital stay. RESULTS: Following ablation, in group A, 90% of the patients (9/10) had fever, 60% (6/10) had bacteraemia, 60% (6/10) had liver abscess, and 10% (1/10) had biliary tract infection. In group B, no cases of bacteraemia or intrahepatic infection were reported, and the incidences of fever, bacteraemia, and liver abscess were substantially lower than group A (p = 0.002, 0.004, 0.004). Duration of fever and length of hospital stay were markedly shorter than group A (p = 0.002 0.003). CONCLUSIONS: Bowel preparation plus targeted antibiotic therapy can significantly reduce the incidences of fever, bacteraemia, and intrahepatic infections in BEA patients undergoing MWA of liver tumours. These preliminary results need to be further validated in randomised trials.

Use of laser capture microdissection to map hepatitis C virus-positive hepatocytes in human liver.

BACKGROUND & AIMS: Hepatitis C virus (HCV) predominantly infects hepatocytes, but many hepatocytes are not infected; studies have shown that HCV antigens cluster within the liver. We investigated spatial distribution and determinants of HCV replication in human liver samples. METHODS: We analyzed liver samples from 4 patients with chronic HCV infection (genotype 1, Metavir scores 0-1) to estimate the proportion of infected hepatocytes and the amount of HCV viral RNA (vRNA) per cell. Single-cell laser capture microdissection was used to capture more than 1000 hepatocytes in grids, to preserve geometric relationships. HCV vRNA and interferon-induced transmembrane protein 3 (IFITM3) messenger RNA (the transcript of an interferon-stimulated gene) were measured in the same hepatocytes by quantitative polymerase chain reaction and assembled in maps to identify areas of high and low HCV replication. RESULTS: Patients' serum levels of HCV RNA ranged from 6.87 to 7.40 log10 IU/mL; the proportion of HCV-infected hepatocytes per person ranged from 21% to 45%, and the level of vRNA ranged from 1 to 50 IU/hepatocyte. Infection was not random; we identified clustering of HCV-positive hepatocytes using infected-neighbor analysis (P < .0005) and distance to the kth nearest neighbor compared with random distributions, obtained by bootstrap simulations (P < .02). Hepatocytes that expressed IFITM3 did not appear to cluster and were largely HCV negative. CONCLUSIONS: We used single-cell laser capture and high-resolution analysis to show that in human liver HCV infects hepatocytes in nonrandom clusters, whereas expression of antiviral molecules is scattered among hepatocytes. These findings show that quantitative single-cell RNA measurements can be used to estimate the abundance of HCV vRNA per infected human hepatocyte and are consistent with cell-cell propagation of infection in the absence of clustered IFITM3.