Patterns of progression: unpredictability and risk of decompensated cirrhosis

Noninvasive monitoring of hepatic damage from hepatitis C virus infection

The mathematical model for the dynamics of the hepatitis C proposed in Avendaño et al. (2002), with four populations (healthy and unhealthy hepatocytes, the viral load of the hepatitis C virus, and T killer cells), is revised. Showing that the reduced model obtained by considering only the first three of these populations, known as basic model, has two possible equilibrium states: the uninfected one where viruses are not present in the individual, and the endemic one where viruses and infected cells are present. A threshold parameter (the basic reproductive virus number) is introduced, and in terms of it, the global stability of both two possible equilibrium states is established. Other central result consists in showing, by model numerical simulations, the feasibility of monitoring liver damage caused by HCV, avoiding unnecessary biopsies and the undesirable related inconveniences/imponderables to the patient; another result gives a mathematical modelling basis to recently developed techniques for the disease assessment based essentially on viral load measurements.

Hepatitis B and hepatitis C

Hepatitis B and C are worldwide infectious hepatitides which are distinct in terms of epidemiology and molecular biology, but which may be quite similar in terms of clinical manifestations and histopathology, in both the acute and chronic stages. Hepatitis B virus (HBV), the human prototype of the Hepadnaviridae family of viruses is not directly cytopathic and viral hepatitis is caused by the cellular immune response to HBV. Patients infected with HBV may also have hepatitis D (delta) virus (HDV) infection, either as co-infection or a superinfection. Hepatitis D virus does not infect independently. Better control of HBV has also led to a decline in the incidence of HDV. Hepatitis C virus (HCV) is on of the Flaviviridae family of viruses, and is quite heterogeneous, with six major genotypes and more than 100 subtypes. Hepatitis C virus circulates as quasispecies that result from mutations accumulated over time, which probably enable HCV to replicate efficiently or resist immune mechanisms. Quasispecies have complicated vaccine development. Both HBV and HCV will recur in the transplanted liver. The risk of developing hepatocellular carcinoma is significantly greater in both HBV- and HCV-infected individuals.

Long-term follow up of chronic hepatitis C patients after alpha-interferon treatment: a functional study

AIM

To evaluate the long-term functional outcome of chronic hepatitis C (CHC) patients treated with interferon (IFN) therapy.

METHODS

Thirty-six patients with CHC were followed up for a mean of 36 months (+/- 19, SD) after a course of IFN therapy. Biochemical, virological (qualitative hepatitis C virus (HCV)-RNA and HCV genotype), and functional (monoethylglycinexylidide (MEGX) test) evaluations were carried out at the time of liver biopsy. Patients were divided into long-term responders (LTR), relapsers (RR), or non-responders (NR) according to IFN therapy outcome. At the end of follow up, patients were non-invasively re-evaluated by means of biochemistry, qualitative HCV-RNA, MEGX test, and liver ultrasonography.

RESULTS

A significant decrease in MEGX values was observed in all patients. However, when patients were examined according to treatment outcome, only NR and RR showed a significant decrease in liver function as compared to pretreatment levels (MEGX30, 80.5 +/- 26.8-62.9 +/- 24.2 ng/mL, P< 0.01; MEGX60, 72.9 +/- 18.1-60.5 +/- 19.7 ng/mL, P< 0.05; MEGXAUC, 3,816 +/- 1,243-3,095 +/- 1,205 ng/mL per h, P< 0.05). On the contrary, LTR patients showed no significant modifications in MEGX values at each sampling time (MEGX,5, 72.9 +/- 31.4-70.3 +/- 29.7 ng/mL; MEGX30, 84.0 +/- 27.6-71.5 +/- 21.8 ng/ mL; MEGX60, 69.5 +/- 26.8-63.2 +/- 14.4 ng/mL; MEGXAUC 4028 +/- 1,378-3,620 +/- 1,041 ng/mL per h). At the end of follow up, LTR patients showed normal liver biochemistry and negativity of serum HCV-RNA, while NR and RR patients showed a significant decrease in platelets.

CONCLUSIONS

In CHC patients long-term response to IFN therapy, besides favoring positive clinical and virologic long-term outcome, results in maintaining preserved liver function. Furthermore, IFN therapy seems to determine a decrease in the rate of functional disease progression, even in NR and RR. The MEGX test may be considered as a useful tool for performing serial follow up of CHC patients.

Clinical features of hepatitis C-infected patients with persistently normal alanine transaminase levels in the Southwestern United States

Approximately one third of patients with chronic hepatitis C virus (HCV) infection have normal alanine transaminase (ALT) levels. We studied the clinical, biochemical, virological, and histological features in patients with persistently normal ALT. A case-control study was conducted on 275 patients with chronic HCV infection, including 75 patients with persistently normal ALT and 200 patients with abnormal ALT. Persistently normal ALT was defined as 4 consecutive ALT values in each patient within a period of 12 months. The average age of the patients was 44 years (range 18 to 69 years). More non-Hispanic whites had persistently normal ALT. The mean serum ferritin level was significantly lower in patients with persistently normal ALT as compared with abnormal ALT (128 +/- 92 ng/mL and 224 +/- 128 ng/mL), respectively (P =.017). The mean HCV-RNA level was significantly lower in patients with persistently normal ALT as compared with abnormal ALT (12 x 10(5) +/- 2.8 x 10(6) copies/mL and 33 x 10(5) +/- 8.0 x 10(6)), respectively (P =.02). Histologically, patients with persistently normal ALT had less severe portal inflammation (P <.05), lobular inflammation (P =.003), piecemeal necrosis (P =.002), fibrosis (P <.05), lower prevalence of cirrhosis (P =.007), as well as a slower fibrosis progression rate (P <.001). Chronic hepatitis C patients with persistently normal ALT have low-activity grade and stage on liver biopsy. In these patients the hepatitis C RNA level was lower compared with abnormal ALT patients, which may explain the slower fibrosis progression rate.

Impact of alcohol on the histological and clinical progression of hepatitis C infection

In patients infected with the hepatitis C virus (HCV), 20% to 30% will progress to cirrhosis in over two to three decades. Viral and host factors that are important in the clinical and histologic progression of HCV infection are not entirely certain. It has been suggested that liver disease is worse in alcoholics infected with HCV. In the present retrospective study, we examined the effect of moderate alcohol intake on the histologic and clinical progression of HCV infection and assessed whether other variables such as gender, length of exposure, mode of exposure, HCV RNA levels, and ferritin levels also independently impacted disease progression. Liver biopsies were analyzed for the degree of fibrosis, presence of cirrhosis, and histologic activity by using the Histologic Activity Index of Knodell. Patients were divided into two groups based on whether their alcohol intake was significant or not significant. Significant alcohol intake was defined as > 40 g alcohol/day in women and > 60 g of alcohol/day in men for > 5 years. Groups were further divided based on the decades of exposure to HCV. There was no difference in the age or length of exposure to HCV in the alcohol and the alcohol-free group. HCV RNA serum levels, ferritin levels, and viral genotypes were similar in both groups. There was a two- to threefold greater risk of liver cirrhosis and decompensated liver disease in the alcohol group. Also, the rate to which subjects developed cirrhosis was faster in the alcohol group with 58% being cirrhotic by the second decade as opposed to 10% being cirrhotic in the nonalcohol group by the second decade. The histologic and clinical acceleration of liver disease was independent of the mode of exposure or sex. In summary, alcohol intake is an independent risk factor in the clinical and histologic progression of HCV infection.