Extent of HCV NS3 protease variability and resistance-associated mutations assessed by next generation sequencing in HCV monoinfected and HIV/HCV coinfected patients.

HCV quasispecies variability represents the background for the selection of mutations and for the development of drug resistance. Natural aminoacid changes in NS3, associated with reduced protease inhibitor susceptibility, have been observed in treatment-naïve patients. Massively parallel sequencing has been used to analyze NS3 quasispecies in patients infected with HCV genotype 1, naive to anti-HCV treatment, with/without HIV-coinfection, to establish the genetic heterogeneity and the presence of amino acid substitutions at positions responsible for drug resistance. Genomes carrying substitutions represented either predominant or minority components of viral quasispecies, and were observed in 85.7% of patients. Multiple substitutions, frequently associated on the same haplotype, were observed in 46.4% of patients. High resistance combinations were not detected, neither on the same genome, nor in the whole quasispecies. Heterogeneity of HCV NS3 was lower in HIV-coinfected as compared to HCV-monoinfected patients, but factors underlying this difference remain to be established. Although the relevance of naturally occurring mutations with respect of resistance development and probability of success of direct acting antivirals is questioned, UDPS may be beneficial to help understanding viral dynamics, providing high resolution view of viral diversity.

Role of hepatitis B virus, hepatitis D virus and other determinants on suppression of hepatitis C viraemia in HIV infected patients with chronic HCV infection: a longitudinal evaluation.

The role of hepatitis B virus (HBV) or hepatitis D virus (HDV) coinfections as determinants of hepatitis C virus (HCV) suppression in the setting of HIV-HCV coinfection are poorly understood. Our aim was to assess whether HCV viral replication may be affected by HBV or HDV coinfection in the setting of immunodeficiency driven by HIV.Among the 138 enrolled patients 28(20.3%) tested HCV RNA negative and 110 (79.7%) tested HCV RNA negative. The HCV RNA negative patients showed an higher rate of HBsAg positivity compared with those tested HCVRNA positive [12/28 (42.9%) and 5/110 (4.6%), respectively]. Patients with HCV-HBV-HDV coinfection had the highest chance of having an undetectable HCV RNA (adjusted odds ratio (AOR): 92.0, 95% confidence interval (CI) 5.7-1483.5, p<0.0001). Furthermore, HBV coinfection per se was also found to be independently associated with negative HCV viraemia (AOR: 18.5, 95% CI 2.4-143.5, p<0.0001). HBsAg-positive patients with negative HCV viraemia maintained undetectable levels over time. Our results support a direct role of HBV and HDV coinfections in suppressing HCV viraemia in HIV infected patients. This effect is durable over time, and is not influenced by HAART including anti-HBV drugs.

The effect of age on response to therapy with peginterferon alpha plus ribavirin in a cohort of patients with chronic HCV hepatitis including subjects older than 65 yr.

OBJECTIVES: In many industrialized countries HCV infection is characterized by an increasing prevalence during ageing; however, data on the efficacy of treatment among older patients are scarce. This study was set up to evaluate the effect of age on the treatment of chronic HCV hepatitis with peginterferon alpha plus ribavirin. METHODS: We retrospectively reviewed medical records of 153 adult patients with chronic HCV hepatitis treated with combination therapy; 30 of them (19.6%) were 65 years of age or older. RESULTS: In multivariable analysis, age groups >/=40 years had similar odds of achieving sustained virologic response (P= 0.71) and significantly lower odds of sustained response compared with younger patients (odds ratio [OR] 0.16, 95% confidence interval [CI] 0.05-0.59, P= 0.006; OR 0.13, 95% CI 0.03-0.49, P= 0.002; OR 0.21, 95% CI 0.05-0.91, P= 0.037 for patients aged 40-49 years, 50-64 years, and older than 64 years, respectively). The effect of age was present in the 74 patients infected with genotype 1 or 4 (P= 0.04), while among the 79 patients with genotype 2 or 3 sustained virologic response rates were relatively uniform, with no statistically significant differences. CONCLUSIONS: The probability of good response to combination treatment with peginterferon alpha plus ribavirin is decreased for patients aged more than 40 years infected with genotype 1 or 4, but patients aged more than 65 had a similar rate of response to those aged 40-64 years. Combination treatment may be safely extended to elderly patients with no major contraindications.

Clinical and genotypic correlates of mutation K65R in HIV-infected patients failing regimens not including tenofovir.

The mutation RT-K65R confers resistance to tenofovir (TDF). Although its prevalence is increasing with the use of this drug, clinical and genotypic correlates of K65R occurrence have yet to be fully identified. Clinical, virological and immunological and genotypic data of patients naïve for TDF who failed HAART regimens and underwent genotypic resistance test (GRT) during 1999-2003 were collected in a database and analyzed retrospectively. Out of 1392 GRT performed for 771 patients, 12 TDF-naïve patients had the K65R mutation with an overall prevalence of 1.6%. Previous AIDS, the use of abacavir, and treatment with efavirenz at GRT were independently associated with a greater risk of expressing K65R, while patients with longer exposure to lamivudine were less likely to present the mutation. Among genotypic correlates, the presence of M184V and NAMs seems to be protective for the emergence of K65R, while a strong positive correlation was found with the Q151M complex mutation. Moreover, the L100I mutation was independently associated with a higher probability of presenting K65R. The selection of mutation K65R in patients failing without TDF is rare. However, exposure to abacavir and/or efavirenz, presence of Q151M and/or L100I, and prior AIDS may favor the selection of this mutation. Conversely, long 3TC exposure, and the presence of M184V or NAMs seem to be protective.

Contamination by hepatitis B and C viruses in the dialysis setting.

BACKGROUND: Hepatitis virus infections continue to be a major concern in the dialysis setting. We studied levels of hepatitis B surface antigen (HBsAg) and hepatitis C virus (HCV) RNA contamination in dialysis units to better define the role of the dialysis environment and machines in the nosocomial transmission of hepatitis viruses. METHODS: Possible contamination by hepatitis B virus (HBV) and HCV was studied by collecting environmental samples in 3 dialysis units located in Rome, Italy. Samples and controls were tested for HBsAg by a microparticle enzyme immunoassay, and for HCV RNA, by qualitative transcription-mediated amplification assay. RESULTS: HCV RNA and HBsAg were detected in 1 of 64 (1.6%) and 1 of 64 samples (1.6%), respectively. The only HCV RNA-positive sample was found in 1 dialysis unit on the external surface of the dialysate (inlet-outlet) connector of a dialysis machine used for HCV-negative patients. The only HBsAg-positive sample was found in another dialysis unit on the internal surface of the blood pressure monitor cuff of a dialysis bed dedicated for HBsAg-positive patients. CONCLUSION: A segregation policy for HBsAg-positive patients is a necessary measure despite its high cost-effectiveness; we found HBsAg contamination in the segregated HBV-infected room. Conversely, the finding of HCV RNA contamination on a dialysis machine not dedicated to HCV-positive patients suggests that isolation of HCV-infected dialysis patients and use of dedicated machines are unjustified. Major attention should be given to strict adherence to infection control measures in the dialysis setting.