The natural course of hepatitis C virus infection after 22 years in a unique homogenous cohort: spontaneous viral clearance and chronic HCV infection

Long-term outcome (35 years) of hepatitis C after acquisition of infection through mini transfusions of blood given at birth

Long-term follow up studies of hepatitis C virus (HCV) infection rarely exceed 20-25 yr. We studied the outcome of HCV infection in 35-yr-old adults infected at birth (1968) through mini transfusions of blood. A retrospective-prospective study was carried out. The cohort included 31 individuals who were given mini blood transfusions (21-30 ml) collected from a donor subsequently revealed to be HCV infected. At enrollment (1998), 18 of 31 (58.1%) recipients had anti-HCV antibody and 16 (88.9%) of them were HCV-RNA positive. All viremic recipients and the infectious donor had the same genotype 1b. Sequence analysis of E1/E2 and NS5b regions, coupled with phylogenetic analysis, indicated that HCV isolates from donor/recipients were linked. Eleven of the 16 viremic recipients gave consent to liver biopsy. Nine had no fibrosis or mild portal fibrosis and 2 had either discrete (Ishak's staging 3) or marked (Ishak's staging 4) fibrosis. During the prospective follow-up period (1998-2003), 2 patients were given therapy, one of whom achieved sustained clinical and virologic response. A second biopsy, performed in 5 patients at a 5 yr interval, revealed no substantial modifications in 4 cases and progression from absence of fibrosis to mild portal fibrosis in the fifth. In conclusion, taking into account the limited study sample, these findings suggest that HCV infection acquired early in life shows a slow progression and mild outcome during the first 35 yr of infection.

Polymorphisms in tumour necrosis factor-alpha, transforming growth factor-beta, interleukin-10, interleukin-6, interferon-gamma, and outcome of hepatitis C virus infection

Cytokines play a key role in the regulation of immune responses. In hepatitis C virus infection (HCV), the production of inappropriate cytokine levels appears to contribute to viral persistence and to affect response to therapy. Cytokine genes are polymorphic at specific sites, and certain mutations located within coding/regulatory regions have been shown to affect the overall expression and secretion of cytokines. The aim of this study was to investigate the frequency of genotypes associated with polymorphisms of TNF-alpha, TGF-beta, IL-10, IL-6, and IFN-gamma and to determine their association with the outcome of HCV infection. Genotyping was carried out by polymerase chain reaction sequence-specific primers on genomic DNA isolated from 158 individuals. Of these, 66 had spontaneously recovered from infection (persistently HCV RNA negative), while 92 had persistent infection (persistently HCV RNA positive). All patients were genotyped as high or low producers of TNF-alpha and IL-6 and high, intermediate, or low producers of TGF-beta, IL-10, and IFN-gamma based on single nucleotide substitutions. A significant proportion of patients with viral clearance were genotyped with a low IL-6 production profile, whereas those with persistent infection were genotyped with a high production profile (P = 0.02). No associations were observed between polymorphisms of TNF-alpha, IL-10, or IFN-gamma and viral clearance or persistent infection. Furthermore, there were no associations between cytokine genotypes and severity of disease. Inheritance of some genotypes associated with polymorphisms of cytokine genes, such as IL-6, may be host genetic factors associated with outcome of HCV in a well-defined ethnically homogeneous cohort.

Ten year incidence of HCV infection in northern Italy and frequency of spontaneous viral clearance

BACKGROUND

Little is known of the incidence of hepatitis C virus (HCV) infection, and the frequency of spontaneous viral clearance in the general population is unknown. We conducted an epidemiological study in two Apennine towns in northern Italy.

METHODS

Anti-HCV (ELISA and RIBA third generation) and HCV-RNA by polymerase chain reaction were tested in thawed sera from an adult general population of Loiano-Monghidoro in 1986 and 1996, obtained in the context of the MICOL (Multicenter Italian Study on Cholelithiasis). In 1999, anti-HCV positive subjects and sex and age matched controls were recalled in order to identify risk factors for acquiring HCV infection and to assess the family composition of anti-HCV+ subjects.

RESULTS

For 1646 subjects, sera were available from both 1986 and 1996 (mean age in 1986 43 (0.39) years). In 1986, 57 (3.46%) subjects were HCV antibody positive (HCV-Ab+). Eight new cases were recorded in 1996: adult incidence was 50.3 cases/100 000 inhabitants/year. Fifty three of 63 (84.1%) HCV-Ab+ sera were also HCV-RNA+. Genotype 2a/2c accounted for 44% and 1b for 47.0% of cases. HCV-Ab+ subjects had higher serum levels of alanine aminotransferase with respect to controls (p<0.005), as did subjects infected with genotype 1 with respect to those with genotype 2 (p<0.05). Eleven of 65 (16.9%) HCV-Ab+ subjects spontaneously cleared HCV-Ab; 7/11 also lost HCV-RNA- in both serum and leucocytes. Sixteen anti-HCV+ subjects belonged to families containing more than one infected member. Married couples accounted for 10 of these 16 subjects. In four of these five married couples, HCV genotype was identical in the two spouses.

CONCLUSIONS

In rural northern Italy, the adult incidence of HCV is approximately 50 cases/100 000 inhabitants/year. Our findings suggest that as many as 17% of infected subjects may spontaneously clear HCV-Ab. Interfamilial transmission seems to have a role in the spread of infection.

Hepatitis C and liver fibrosis

Chronic hepatitis C progresses to cirrhosis within 20 years in an estimated 20-30% of patients, while running a relatively uneventful course in most others. Certain HCV proteins, such as core and NS5A, can induce derangement of lipid metabolism or alter signal transduction of infected hepatocytes which leads to the production of reactive oxygen radicals and profibrogenic mediators, in particular TGF-beta1. TGF-beta1 is the strongest known inducer of fibrogenesis in the effector cells of hepatic fibrosis, i.e. activated hepatic stellate cells and myofibroblasts. However, fibrogenesis proceeds only when additional profibrogenic stimuli are present, e.g. alcohol exposure, metabolic disorders such as non-alcoholic steatohepatitis, or coinfections with HIV or Schistosoma mansoni that skew the immune response towards a Th2 T cell reaction. Furthermore, profibrogenic polymorphisms in genes that are relevant during fibrogenesis have been disclosed. This knowledge will make it possible to identify those patients who are most likely to progress and who need antiviral or antifibrotic therapies most urgently. However, even the best available treatment, the combination of pegylated interferon and ribavirin, which is costly and fraught with side effects, eradicates HCV in only 50% of patients. While the suggestive antifibrotic effect of interferons (IF-gamma>alpha,beta), irrespective of viral elimination, has to be proven in randomised prospective studies, additional, well tolerated and cost-effective antifibrotic therapies have to be developed. The combination of cytokine strategies, e.g. inhibition of the key profibrogenic mediator TGF-beta, with other potential antifibrotic agents appears promising. Such adjunctive agents could be silymarin, sho-saiko-to, halofuginone, phosphodiesterase inhibitors, and endothelin-A-receptor or angiotensin antagonists. Furthermore, drug targeting to the fibrogenic effector cells appears feasible. Together with the evolving validation of serological markers of hepatic fibrogenesis and fibrolysis an effective and individualised treatment of liver fibrosis is anticipated.

Polyethylene glycol-interferon: current status in hepatitis C virus therapy

In chronic hepatitis C infection, combination therapy with interferon (IFN)-alpha and ribavirin leads to sustained virological response rates of 40-45%. However, treatment outcome is still disappointing in patients infected with hepatitis C virus (HCV) genotype 1, high viral load or advanced liver fibrosis. Due to significant side-effects of therapy, dose reductions and discontinuations of therapy are frequent and lead to further decreased response rates. The development of modified IFN is the latest step to improve treatment options for chronic hepatitis C. Conjugation of the polymer polyethylene glycol (PEG) to IFN extends half-life in comparison to conventional IFN and thereby increases antiviral activity. It allows once-weekly dosing and increases sustained response rates without changing the safety profile. The PEG-IFN monotherapy is twice as effective as IFN-alpha three times weekly. The combination of PEG-interferon and ribavirin improves the overall sustained response rates to 54-56% and represents the new standard therapy for patients with chronic hepatitis C infection in most patients.

Treatment of chronic hepatitis C with PEGylated interferon and ribavirin

Treatment with interferon alfa combined with ribavirin is successful in approximately 40% to 45% of patients with chronic hepatitis C viral infection (HCV). However, response rates are disappointing in patients who are difficult to treat, such as those infected with HCV genotype 1, high viral load, or advanced liver fibrosis. In addition, low tolerability and significant side effects of therapy frequently lead to dose reduction and treatment discontinuation, decreasing response rates further. Thus, investigation of new treatment options and innovations for chronic HCV infection are vital. This review describes recent advances in the treatment of HCV infection with PEGylated interferon (interferon modified with polyethylene glycol [PEG] ) combined with ribavirin.