No significant changes in levels of hepatitis C virus (HCV) RNA by competitive polymerase chain reaction in blood samples from patients with chronic HCV infection

Chronic hepatitis C virus infection and increases in viral load in a prospective cohort of young, HIV-uninfected injection drug users

BACKGROUND

Chronic hepatitis C (HCV) infection, defined as persistent RNA (viral load) for at least 6 months, accounts for up to 50% of all cirrhosis, end-stage liver disease and liver cancer cases. Moreover, elevated HCV viral load is consistently associated with high infectivity and poor therapy response. This study aims to identify modifiable behavioral correlates both chronic HCV infection and increases in viral load over time among injection drug users (IDUs).

METHODS

Cross-sectional and longitudinal analyses were performed using self-interview and serological data from a prospective cohort study (2002-2006) among young (age 18-35), HIV-negative, HCV therapy-naïve IDUs (n=113) from metropolitan Chicago, Illinois, USA.

RESULTS

After adjustment for age, gender and race/ethnicity, using drugs measured or mixed in someone else's syringe (odds ratio=2.7, 95% confidence interval: 1.1, 6.7) was associated with chronic (n=75, 66%) versus resolved (n=38, 34%) HCV infection status. Among chronically-infected IDUs, injecting with a new, sterile syringe infrequently (<1/2 half the time when injecting) compared to frequently (1/2 the time or more when injecting) was associated with increases in viral load over time after adjusting for age, gender, race/ethnicity and time effects.

CONCLUSIONS

Reductions in risky injection-related practices among young IDUs may ameliorate both the burden of chronic HCV infection-related liver disease and elevated viral load-related poor treatment response.

Differences in the factors associated with serum viral load between genotypes 1 and 2 in patients with chronic hepatitis C

PURPOSE

The serum hepatitis C virus (HCV) load is persistently stable in patients with untreated chronic hepatitis C, but its differences between individuals vary widely (above 4 logU/mL). Because serum viral load is an important factor for predicting clinical outcome of interferon-based antiviral therapy, this study was performed to clarify the factors associated with serum viral load in chronic hepatitis C patients.

METHODS

We retrospectively analyzed data from 669 chronic hepatitis C patients with HCV genotype 1 or 2 infection. Stepwise regression analysis was used to estimate the relationship between demographic, viral, or biochemical variables and serum viral load.

RESULTS

In univariate analysis, serum lipid profiles, such as total cholesterol, low-density lipoprotein (LDL) and triglyceride levels, and hemoglobin A1c (HbA1c) were correlated with the serum HCV viral load. In multivariate analysis, HCV genotype 1 infection and higher total cholesterol levels were associated with higher viral load. After stratification by HCV genotype, the serum viral load was associated with triglyceride and HbA1c in genotype 1 and with platelet counts and LDL in genotype 2. Histological data (413 patients) showed correlation between severe liver fibrosis and decreased serum viral load in patients with HCV genotype 2 but not genotype 1 infection.

CONCLUSIONS

These results suggest that viral kinetics is affected by different host factors for genotypes 1 and 2.

Predictors of hepatitis C virus RNA levels in a prospective cohort study of drug users

High levels of hepatitis C virus (HCV) RNA are associated with a poor response to treatment of chronic hepatitis C, and a substantial reduction in HCV RNA levels predicts a favorable treatment response. We prospectively studied time-dependent and time-independent predictors of HCV RNA levels in 264 drug users with chronic HCV infection. Interviews on medical history and high-risk behaviors, phlebotomy for HIV viral load, serum HCV RNA levels as measured by the COBAS Amplicor HCV Monitor (Roche Diagnostics, Branchburg, NJ), and a lymphocyte subset assay were performed. Factors associated with HCV RNA levels over time were analyzed using a linear mixed model. Nearly 70% of the participants were men, two thirds were Hispanic, and the mean age was 46 years. HCV RNA levels increased over time. Older age (P < 0.001), HIV seropositivity (P = 0.03), and HCV nongenotype 1 (P = 0.05) were predictors of higher HCV RNA levels on multivariate analysis. Among 142 HIV-seropositive participants, a detectable HIV-1 viral load (P < 0.001) and recent alcohol use (P = 0.02) were predictors of higher HCV RNA levels. The predictors of higher HCV RNA levels found in this longitudinal study are consistent with those of prior cross-sectional studies. Further studies are warranted to determine if treatment of alcohol use affects HCV RNA levels.

A phase I trial of an antisense inhibitor of hepatitis C virus (ISIS 14803), administered to chronic hepatitis C patients

BACKGROUND/AIMS

ISIS 14803 is a 20-unit antisense phosphorothioate oligodeoxynucleotide that binds to hepatitis C virus (HCV) RNA at the translation initiation region of the internal ribosome entry site (IRES) and inhibits protein expression in cell culture and mouse models. This Phase I, open-label, dose-escalation trial of ISIS 14803 was performed in chronic HCV patients.

METHODS

At least 7 days after receiving an initial single dose, twenty-eight patients received 0.5-3 mg/kg ISIS 14803 thrice weekly for 4 weeks by intravenous infusion or subcutaneous injection.

RESULTS

In most patients, the 4-week treatment did not reduce plasma HCV RNA. However, 3 patients receiving > or =2 mg/kg had transient HCV reductions of 1.2-1.7 log(10) that persisted < or =32 days. These reductions were accompanied by asymptomatic, self-resolving elevations in serum alanine transaminase (ALT) levels to >10x the upper limit of normal. Two other patients had ALT flares without plasma HCV reduction. No clinical signs, symptoms of hepatic dysfunction, or laboratory changes in albumin or prothrombin time accompanied ALT elevations.

CONCLUSIONS

ISIS 14803 treatment was associated with HCV reductions in only 3/28 patients. ALT flares in 5 patients also occurred. Further studies to evaluate ISIS 14803 treatment and the mechanisms of the ALT flares are now required.

Routine serologic testing for hepatitis C virus infection should be instituted among dialysis patients

Since the cloning of hepatitis C virus (HCV), a number of serologic and virologic tests for detecting infections with this virus have been made available for clinical practice. This led to the recognition of HCV as a major health hazard in hemodialysis (HD) centers. Yet the nephrology community has not been offered explicit recommendations about routine serologic testing for HCV of dialysis patients and consequently has remained unclear and divided about the utility of this testing. This review presents evidence in support of instituting routine serologic testing for HCV among dialysis patients. It concludes that because of the peculiar features of HCV infection in HD patients, serologic testing for HCV is the only means for unequivocal diagnosis of hepatitis C and an irreplaceable instrument for monitoring the incidence and the prevalence of the infection in this population. Serologic surveillance for HCV infection is crucial for identifying the association of new cases of HCV infection with potential risk factors for HCV transmission, particularly nosocomial, that can be modified in a way to prevent further dissemination of the virus. Data collected from routine serologic testing for HCV will undoubtedly improve our understanding of the epidemiology of HCV in the dialysis population and will provide a strong foundation for developing preventive measures and infection control strategies that are highly effective in controlling HCV infection. Routine serologic testing for HCV is also of direct benefit to the individual patient since establishing the HCV serologic status of each patient is important for optimizing patient care.

Maintenance hemodialysis decreases serum hepatitis C virus (HCV) RNA levels in hemodialysis patients with chronic HCV infection

OBJECTIVE

Hepatitis C virus (HCV) infection is a major complication among hemodialysis patients the world over. To determine the natural course of HCV viremic levels in patients on maintenance hemodialysis, we prospectively quantified the HCV RNA levels in serial blood samples from hemodialysis patients and compared them with those in nonuremic subjects.

METHODS

The population studied included 98 hemodialysis patients and 228 nonuremic subjects with chronic HCV infection. HCV RNA was detected by polymerase chain reaction (PCR) and the levels were determined by branched DNA probe assay. HCV RNA genotypes were determined by PCR using type-specific primers.

RESULTS

HCV RNA levels were significantly lower in hemodialysis patients (median, 0.4x10(6) genome equivalent [Meq]/ml) than in nonuremic subjects (median, 3.0 Meq/ml) (p<0.05). HCV of genotype 1b was prevalent in the hemodialysis patients (81.6%) and nonuremic subjects (88.6%). HCV RNA levels in 20 hemodialysis patients with genotype 1b were significantly reduced after each hemodialysis procedure (p<0.05). The 3-yr prospective observation from 1995 to 1998 showed a significant decrease of HCV RNA levels in 47 hemodialysis patients with genotype 1b (median, 1.9-0.9 Meq/ml, p<0.05), whereas levels in 155 nonuremic subjects with genotype 1b did not decrease (median, 2.6-3.0 Meq/ml). There were no patients or nonuremic subjects with undetectable HCV RNA by a PCR assay during the observation period.

CONCLUSIONS

These observations suggest that maintenance hemodialysis decreases the HCV RNA levels in hemodialysis patients with chronic HCV infection, but does not produce clearance of the viremia.

Biological dynamics of viral load in hemodialysis patients with hepatitis C virus

The biological dynamics of hepatitis C virus (HCV) viremia in uremic patients with chronic infection have not been fully characterized. We prospectively studied fluctuations of HCV-RNA in sera from 52 patients with end-stage renal disease who were undergoing maintenance hemodialysis (HD) and had chronic HCV infection. We measured HCV viremia monthly over the course of 13 months with the branched-chain DNA (bDNA) signal amplification assay and prospectively analyzed liver function, expressed by monthly serum aspartate (AST) and alanine aminotransferase (ALT) determinations. We observed three different patterns of HCV viremia: (1) patients persistently positive by bDNA assay (persistent viremia; 23 of 52 patients; 44%), (2) individuals with alternatively positive and negative results (intermittent viremia; 17 of 52 patients; 33%), and (3) patients persistently negative by bDNA assay (12 of 52 patients; 23%). The HCV viral load over the follow-up was greater among patients with persistent compared with intermittent viremia (persistent, 31.7 x 10(5) Eq/mL; range, 6.3 x 10(5) to 16.03 x 10(6) Eq/mL versus intermittent, 10.4 x 10(5) Eq/mL; range, 1.1 x 10(5) to 9.4 x 10(6) Eq/mL; P = 0.0001). In addition, patients with persistent viremia had over time greater AST and/or ALT activities than the intermittent group (AST: persistent, 26.5 IU/L; range, 9.6 to 73.7 IU/L versus intermittent, 21.3 IU/L; range, 8 to 56.8 IU/L; P = 0.001 and ALT: persistent, 14.7 IU/L; range, 3.7 to 57.9 IU/L versus intermittent, 10.9 IU/L; range, 2.3 to 52.1 IU/L; P = 0.001). In the group with persistent viremia, the mean difference between maximum and minimum values of HCV-RNA observed in each individual patient was 2.09 +/- 0.7 natural logarithm (Log(n)) and in intermittent viremic patients, 1.55 +/- 1 Log(n) (P = 0.045). The HCV load at study entry (19.4 x 10(5) Eq/mL) was rather low and did not change versus the end of follow-up in all patients (P = not significant [NS]). In the entire group, the fluctuations in HCV-RNA levels over time between and within individuals were not significant (P = NS). No difference in variability of HCV-RNA values over time between patients infected with different HCV genotypes was seen. In conclusion, three different patterns of HCV viremia in HD over time were assessed; one third of viremic patients had intermittent viremia, and those patients had less HCV-RNA, enzyme-linked immunosorbent assay, and aminotransferase activity than did patients with persistent HCV load. Larger fluctuations in HCV RNA levels occurred in patients with persistent than with intermittent HCV viremia. However, the viremic HCV load was low and relatively stable over a 13-month follow-up in our population. Studies with longer observation periods are warranted to understand fully the natural history of HCV in these immunosuppressed individuals.

Sequential serum hepatitis C viral RNA levels longitudinally assessed by branched DNA signal amplification

The aim of this study was to determine the stability of viral load over an extended period in patients with chronic hepatitis C virus (HCV). Sequential serum specimens collected from fourteen non-alcoholic adult patients with chronic HCV between 1990 and 1997 were tested retrospectively for HCV RNA levels by branched DNA assay (Quantiplex HCV RNA 2.0 [Chiron Diagnostics, Emeryville, CA]). A minimum of three serum samples was obtained at various intervals from each patient. None of the patients received antiviral therapy. Liver biopsies, available for 10 of 14 patients, showed mild or moderate hepatitis in seven and cirrhosis in three (one developed cirrhosis during follow-up). RIBA strip immunoassay showed that 7, 3, and 4 patients had viral genotypes 1, 2, and 3, respectively. The follow-up time averaged 5.3 years (range, 3.7 to 6.6 years). Eight patients (57.2%) showed increased viral levels from baseline to follow-up, the remaining six patients (42.8%) showed decreased viral levels. The three cirrhotic patients had the highest viral levels over time. The mean change was a 0.29-fold decrease (median, +1.14 [corrected]; range, -17.49 to +7.32). A less than twofold change in either direction was demonstrated for six patients (42.8%), and a less than threefold change was demonstrated for 10 patients (71.4%). Variation from baseline to last follow-up as calculated by log determination showed that the viremic load varied less than one log10 in all but one individual. These results show that viral load remains relatively stable over prolonged periods in most untreated patients with chronic hepatitis C.