Hepatitis C infection and the patient with end-stage renal disease

Replication and IRES-dependent translation are both affected by core coding sequences in subgenomic GB virus B replicons

The yield of G418-resistant Huh7 cell clones bearing subgenomic dicistronic GB virus B (GBV-B) is significantly affected by the insertion of a portion of the viral core gene between the GBV-B 5' untranslated region and the exogenous neomycin phosphotransferase selector gene (A. De Tomassi, M. Pizzuti, R. Graziani, A. Sbardellati, S. Altamura, G. Paonessa, and C. Traboni, J. Virol. 76:7736-7746, 2002). In this report, we have dissected this phenomenon, examining the effects of the insertion of core sequences of different lengths on GBV-B IRES-dependent translation and RNA replication by using experimental approaches aimed at analyzing these two aspects independently. The results achieved indicate that an enhancement of translation efficiency does occur and that it correlates with the length of the inserted core sequences. Interestingly, the insertion of these sequences also has a direct similar effect on the efficiency of replication of the GBV-B replicon. These results suggest that in GBV-B replicon RNA and potentially in the complete viral genome, the core coding sequences not only are part of the IRES but also take part in the replication process, independently of the presence of the corresponding whole protein.

Unexpected distribution of hepatitis C virus genotypes in patients on hemodialysis and kidney transplant recipients

The distribution of hepatitis C virus (HCV) genotypes in patients on hemodialysis and in kidney transplant recipients was compared with that observed in a control group composed of HCV-infected individuals from the general population. A total of 340 patients were included in the study: 46 with end-stage renal disease on regular hemodialysis treatment, 22 kidney transplant recipients and 272 controls matched for sex and age at a 4:1 ratio (controls to patient). HCV genotype was determined by sequencing of the 5' untranslated region of the HCV genome. No difference was observed in the distribution of HCV genotypes in hemodialysis patients and renal transplant patients (P = 0.47). However, when each of these groups was compared with the control group, a significant difference was detected in the genotype distribution (P < 0.001). In hemodialysis and renal transplant patients the most prevalent subtype was 1a, followed by 1b, 3, and other less prevalent genotypes (2, 4, and 5), whereas in the control group the most prevalent subtype was 1b, followed by 3, 1a, and others. That observation may reflect differences in the epidemiology of HCV infection, viral characteristics and host factors in renal patients in comparison to the control group.

Understudied populations with hepatitis C

Managing patients with hepatitis C virus (HCV) infection consists primarily of antiviral treatment, currently with peginterferon and ribavirin. Unfortunately, treatment recommendations derive largely from trials that have focused on highly selected patient populations. As a consequence of the strict inclusion and exclusion criteria in these studies, more than half of all HCV-infected patients would be ineligible for enrollment. Even among the selected patients enrolled into studies, only 50% achieve a sustained virological response (SVR). Patients not eligible for current therapies include those with mild disease and normal alanine aminotransferase (ALT) levels, patients with advanced and decompensated liver disease, children, the elderly, patients with ongoing or recent alcohol and substance abuse, renal disease, human immunodeficiency virus (HIV) infection, severe psychiatric or neurologic illness, autoimmune disorders, solid organ transplant, and other significant comorbid conditions. Because these patients have been excluded from most clinical trials, little is known about the safety or efficacy of therapy in these populations. The expense and side effects of therapy are also an impediment to treatment of patients who are on public assistance, in prisons, and in institutions. Clearly, new efforts and new approaches are needed to expand the eligibility for antiviral therapy of hepatitis C and make treatment more available for understudied populations with this disease.

Understudied populations with hepatitis C

Managing patients with hepatitis C virus (HCV) infection consists primarily of antiviral treatment, currently with peginterferon and ribavirin. Unfortunately, treatment recommendations derive largely from trials that have focused on highly selected patient populations. As a consequence of the strict inclusion and exclusion criteria in these studies, more than half of all HCV-infected patients would be ineligible for enrollment. Even among the selected patients enrolled into studies, only 50% achieve a sustained virological response (SVR). Patients not eligible for current therapies include those with mild disease and normal alanine aminotransferase (ALT) levels, patients with advanced and decompensated liver disease, children, the elderly, patients with ongoing or recent alcohol and substance abuse, renal disease, human immunodeficiency virus (HIV) infection, severe psychiatric or neurologic illness, autoimmune disorders, solid organ transplant, and other significant comorbid conditions. Because these patients have been excluded from most clinical trials, little is known about the safety or efficacy of therapy in these populations. The expense and side effects of therapy are also an impediment to treatment of patients who are on public assistance, in prisons, and in institutions. Clearly, new efforts and new approaches are needed to expand the eligibility for antiviral therapy of hepatitis C and make treatment more available for understudied populations with this disease.