The response of hepatitis C virus and TT virus to high dose and long duration interferon-alpha therapy in naïve chronic hepatitis C patients

Polymorphism of interferon-gamma gene at position +874 and clinical characteristics of chronic hepatitis C

A T-to-A polymorphic sequence at position +874 in the interferon (IFN)-gamma gene (+874 IFN-gamma) might be associated with disease susceptibilities. To investigate the influence of +874 IFN-gamma polymorphism on the hepatitis C virus (HCV) viral load and the severity of liver disease, the single nucleotide polymorphism (SNP) was determined in 302 histologically proved chronic hepatitis C (CHC) patients [M/F: 180/122, mean age: 48.8 +/- 11.6 years, HCV genotype 1b: 147 (48.7%), liver cirrhosis: 29 (9.6%)] by using a polymerase chain reaction-sequence specific primers (PCR-SSP) approach. The distribution of genotypes for +874 IFN-gamma were T/T: 12 (4.0%), T/A: 71 (23.5%), and A/A: 219 (72.5%) and 27.5% (83/302) of patients' inherited T allele. The mean age of patients without A allele was significantly lower than other patients (41.7 +/- 11.3 vs 49.2 +/- 11.5 years, P = 0.028). Patients with the T allele of +874 IFN-gamma had a significantly higher rate of liver cirrhosis than patients with homozygote A allele (15.7% vs 7.3%, P = 0.028). By multivariate logistic regression analyses, T allele of +874 IFN-gamma and age were independent factors associated with cirrhosis (odds ratio/95% confidence interval: 2.519/1.128-5.622 and 1.065 /1.025-1.107, respectively). In conclusion, the authors' findings indicate that inheritance of +847 IFN-gamma polymorphism is associated with the cirrhosis in patients with CHC.

Polymorphisms in the interferon-γ gene at position +874 in patients with chronic hepatitis C treated with high-dose interferon-α and ribavirin

To investigate the influence of the T-to-A polymorphic sequence at position +874 in the interferon (IFN)-gamma gene (+874 IFN-gamma) on the response to combination therapy with high-dose interferon and ribavirin, the single nucleotide polymorphisms were determined by using a polymerase chain reaction sequence-specific primers approach in 150 histologically proved chronic hepatitis C (CHC) patients. The distribution of genotypes for +874 IFN-gamma were T/T: 6 (4.0%), T/A: 31 (20.7%) and A/A: 113 (75.3%) and 24.7% (37/150) of patients were inherited T allele. After undergoing combination therapy with high-dose IFN-alpha and ribavirin, 70.7% (106/150) of patients achieved sustained viral response (SVR). Based on multivariate regression analyses, the independent factors predicting HCV SVR after combination therapy were HCV genotype non-1b (P<0.001) and low pretreatment HCV RNA levels (P=0.041) (odds ratios/95% C.I.: 10.150/4.023-25.609 and 0.581/0.345-0.979, respectively). No association between genotypes, A or T alleles of +874 IFN-gamma and response to combination therapy with high-dose IFN-alpha and ribavirin. In conclusion, we found that with high SVR rates after combination therapy with high-dose IFN-alpha and ribavirin, HCV genotypes and pretreatment serum HCV RNA levels, but not inheritance of the IFN-gamma polymorphism at the position +847, were predictors for SVR.

Co-infection of SENV-D among chronic hepatitis C patients treated with combination therapy with high-dose interferon-alfa and ribavirin

AIM: The clinical significance of co-infection of SENV-D among patients with chronic hepatitis C (CHC) and response of both viruses to combination therapy with high-dose interferon-alfa (IFN) plus ribavirin remain uncertain and are being investigated.

METHODS: Total 164 (97 males and 67 females, the mean age 48.1 ± 11.4 years, range: 20-73 years, 128 histologically proved) naive CHC patients were enrolled in this study. SENV-D DNA was tested by PCR method. Detection of serum HCV RNA was performed using a standardized automated qualitative RT-PCR assay (COBAS AMPLICOR HCV Test, version 2.0). HCV genotypes 1a, 1b, 2a, 2b, and 3a were determined by using genotype-specific primers. Pretreatment HCV RNA levels were determined by using the branched DNA assay (Quantiplex HCV RNA 3.0). There are 156 patients receiving combination therapy with IFN 6 MU plus ribavirin for 24 wk and the response to therapy is determined.

RESULTS: Sixty-one (37.2%) patients were positive for SENV-D DNA and had higher mean age than those who were negative (50.7 ± 10.6 years vs 46.6 ± 11.6 years, P = 0.026). The rate of sustained viral response (SVR) for HCV and SENV-D were 67.3% (105/156) and 56.3% (27/48), respectively. By univariate analysis, the higher rate of SVR was significantly related to HCV genotype non-1b (P < 0.001), younger ages (P = 0.014), lower pretreatment levels of HCV RNA (P = 0.019) and higher histological activity index (HAI) score for intralobular regeneration and focal necrosis (P = 0.037). By multivariate analyses, HCV genotype non-1b, younger age and lower pretreatment HCV RNA levels were significantly associated with HCV SVR (odds ratio (OR)/95% confidence interval (CI): 12.098/0.02-0.19, 0.936/0.890-0.998, and 3.131/1.080-9.077, respectively). The SVR of SENV-D was higher among patients clearing SENV-D than those who had viremia at the end of therapy (P = 0.04).

CONCLUSION: Coexistent SENV-D infection, apparently associated with higher ages, is found in more than one-third Taiwanese CHC patients. Both HCV and SENV-D are highly susceptible to combination therapy with high-dose IFN and ribavirin and SENV-D co-infection does not affect the HCV response. HCV genotype, pretreatment HCV RNA levels and age are predictive factors for HCV SVR.

Effect of immune modulation on TT virus (TTV) and TTV-like-mini-virus (TLMV) viremia

The present study was designed to investigate how two chronically replicating viruses, TT virus (TTV) and TTV-like mini virus (TLMV), interact with host defence systems. Successive serum samples from three groups of subjects, undergoing modifications of their antiviral defence, were tested by real-time PCR to measure changes in viral titers, and by sequence analyses to indicate whether increases in viremia could be attributed to infection with an unfamiliar strain: 1) in patients receiving immunosuppressants subsequent to kidney transplantation, viral titers tended to increase; 2) in soldiers undergoing extreme training known to cause immunosuppression, insignificant increases in titers were observed; and 3) interferon treatment of patients with hepatitis C virus caused a temporary decrease in TTV and TLMV titers. Increases in viremia were associated only occasionally with the appearance of novel strains. The above results add to knowledge on how these viruses are influenced by the host.

Serum concentrations of TT virus and TT virus-like mini virus in patients developing AIDS

Changes in viraemia of two chronically replicating circoviruses, TT virus (TTV) and TTV-like mini virus (TLMV), were investigated in patients developing HIV-related immune deficiency. In a few cases, episodes of a considerable increase in viraemia were observed, but in most patients there were no discernible increases as immune deficiency progressed. The deterioration of immune function associated with AIDS did not by itself have any obvious effect on TTV and TLMV.