Relationship between viral genotype and viral load in patients with chronic hepatitis C

Community viral load and hepatitis C virus infection: Community viral load measures to aid public health treatment efforts and program evaluation

BACKGROUND

Hepatitis C virus (HCV) infection is the most prevalent blood-borne infection and causes more deaths than any other infectious disease in the US. Incident HCV infection in the US increased nearly 300 % between 2010 and 2015, Community viral load (CVL) measures have been developed for HIV to measure both transmission risk and treatment engagement in programs or areas.

OBJECTIVE

This paper presents a systematic review exploring the published literature on CVL constructs applied to HCV epidemiology and proposes novel CVL measures for HCV.

STUDY DESIGN AND SETTING

A systematic review was conducted of electronic databases; the search sought to identify published literature on HCV which discussed or applied CVL measures to HCV epidemiology. Novel CVL measures were constructed to apply to HCV.

RESULTS

No reports examining quantitative measures of HCV CVL were identified. Using the HIV CVL literature and the specific characteristics of HCV epidemiology, five HCV CVL measures are proposed. Narrower measures focusing on those engaged-in-care may be useful for program evaluation and broader measures including undiagnosed people may be useful for surveillance of HCV transmission potential.

CONCLUSION

Despite their potential value, CVL constructs have not yet formally been developed and applied to HCV epidemiology. The CVL measures proposed here could serve as valuable HCV program and surveillance measures. There is a need for informative surveillance measures to enhance policy and public health responses to achieve HCV control. Further study of these proposed HCV CVL measures to HCV epidemiology is warranted.

Advanced liver fibrosis by transient elastography, fibrosis 4, and alanine aminotransferase/platelet ratio index among Asian hepatitis C with and without human immunodeficiency virus infection: role of vitamin D levels

BACKGROUND AND AIM

Vitamin D insufficiency plays an important role in liver fibrosis in hepatitis C virus (HCV)-infected patients. We assessed liver fibrosis by transient elastography and 25 hydroxy vitamin D [25(OH)D] status in HCV-infected patients, with (HIV/HCV) or without HIV co-infection (HCV) from Thailand.

METHODS

Fibrosis stage was defined as mild (< 7.1 kPa); moderate (7.2-9.4 kPa); severe (9.5-14 kPa), and cirrhosis (> 14 kPa). Hypovitaminosis D was defined as 25(OH)D < 30 ng/mL. Logistic regression analyses were used to assess predictors for significant fibrosis. Serum 25(OH) D levels, HCV genotypes (GT), interleukin-28B (IL28B) and HCV-RNA were assessed.

RESULTS

A total of 331 HCV and 130 HIV/HCV patients were enrolled (70% male, 35% people who inject drugs [PWIDs]). HCV GT distribution was as follows: GT3 47%, GT1 34%, GT6 17%. IL-28B CC genotype (rs12979860) were found in 88% of HIV/HCV and 85% of HCV. In HCV, liver fibrosis was mild in 56.5%; moderate in 18.4%; severe in 12.4%; and cirrhosis in 12.7%. In HIV/HCV, these figures were 30.6%, 27.8%, 17.6%, and 24.1%, respectively. Patients with significant fibrosis were more often male, older, with HIV infection, hypovitaminosis D, and less likely to be infected with GT6. Factors associated with significant fibrosis by multivariate analysis were HIV infection (adjusted odd ratio [95% confidential interval]: 2.67, 1.20-5.93), P = 0.016, Fib-4 score > 1.45 (6.30, 2.70-14.74), P < 0.001, and hypovitaminosis D (2.48, 1.09-5.67), P = 0.031. GT 6 was less likely to have advanced liver fibrosis (0.17, 0.05-0.65), P = 0.01.

CONCLUSIONS

HIV infection, Fib-4 score > 1.45, and hypovitaminosis D are strong and independent predictors for the presence of advanced fibrosis in our HCV-infected patients. These data highlight the urgent need of HCV treatment and vitamin D supplement in resource-limited settings.

Cannabinoid receptor 2-63 QQ variant is associated with persistently normal aminotransferase serum levels in chronic hepatitis C

BACKGROUND AND AIM

To evaluate in anti-HCV-positive patients the clinical impact of the rs35761398 variant of the CNR2 gene leading to the substitution of Gln (Q) of codon 63 of the cannabinoid receptor 2 (CB2) with Arg (R).

PATIENTS AND METHODS

253 consecutive anti-HCV-/HCV-RNA-positive patients were enrolled, of whom 53 were HCV carriers with persistently normal ALT (PNALT group) and 200 had a history of steadily abnormal serum ALT values (abnormal ALT group). All patients were naive for antiviral therapy and were screened for the CNR2 rs35761398 polymorphism by a TaqMan assay.

RESULTS

Subjects in the PNALT group, compared with those in the abnormal ALT group were older (58.5±12 vs. 50.7±12.4 years, p = 0.001), more frequently female (66% vs. 42%, p = 0.003), with lower body mass index (BMI) (24.5±3.1 vs. 26.6±4.6, p = 0.003), and more frequently with HCV genotype 2 (43.1% vs 17.7%, p = 0.0002) and CB2-63 QQ variant (34% vs. 11%, p = 0.0001). Considering all 253 patients, no difference in the demographic, biochemical, or virological data was observed between patients in the different CB2-63 variants. The logistic regression analysis identified CB2-63 QQ, HCV genotype 2, older age and lower BMI as independent predictors of PNALT (p<0.00001).

DISCUSSION

The CB2-63 QQ variant in HCV patients was independently associated with the PNALT status.

Replicative homeostasis III: implications for antiviral therapy and mechanisms of response and non-response

While improved drug regimens have greatly enhanced outcomes for patients with chronic viral infection, antiviral therapy is still not ideal due to drug toxicities, treatment costs, primary drug failure and emergent resistance. New antiviral agents, alternative treatment strategies and a better understanding of viral pathobiology, host responses and drug action are desperately needed. Interferon (IFN) and ribavirin, are effective drugs used to treat hepatitis C (HCV), but the mechanism(s) of their action are uncertain. Error catastrophe (EC), or precipitous loss of replicative fitness caused by genomic mutation, is postulated to mediate ribavirin action, but is a deeply flawed hypothesis lacking empirical confirmation. Paradoxically ribavirin, a proven RNA mutagen, has no impact on HCV viraemia long term, suggesting real viruses, replicating in-vitro, as opposed to mathematical models, replicating in-silico, are likely to resist EC by highly selective replication of fit (~consensus sequence) genomes mediated, in part, by replicative homeostasis (RH), an epicyclic mechanism that dynamically links RNApol fidelity and processivity and other viral protein functions. Replicative homeostasis provides a rational explanation for the various responses seen during treatment of HCV, including genotype-specific and viral load-dependent differential response rates, as well as otherwise unexplained phenomena like the transient inhibition and rebound of HCV viraemia seen during ribavirin monotherapy. Replicative homeostasis also suggests a primarily non-immunological mechanism that mediates increased immune responsiveness during treatment with ribavirin (and other nucleos(t)ide analogues), explicating the enhanced second-phase clearance of HCV ribavirin promotes and, thus, the apparent immunomodulatory action of ribavirin. More importantly, RH suggests specific new antiviral therapeutic strategies.

Predictors of Liver Fibrosis in HIV-Infected Patients with Chronic Hepatitis C Virus (HCV) Infection: Assessment Using Transient Elastometry and the Role of HCV Genotype 3

BACKGROUND

Liver fibrosis is accelerated in patients coinfected with hepatitis C virus (HCV) and human immunodeficiency virus (HIV). The reasons for this faster liver disease progression are unclear, although higher plasma HCV RNA levels and distinct HCV genotype distribution in this population, compared with in HCV-monoinfected subjects, could play a role.

METHODS

Liver fibrosis was assessed using elastometry in all consecutive HIV-infected patients with chronic hepatitis C who attended our institution (Hospital Carlos III, Madrid) during the past 12 months. Hepatic stiffness was measured in kiloPascal units (kPa) and was interpreted on the basis of Metavir score: no or mild fibrosis (score, F0-F1) when liver stiffness is < or =7.1 kPa, and fibrosis with septa or cirrhosis (F2-F4) when >7.1 kPa.

RESULTS

A total of 283 patients (71% were male; mean age, 42 years; 94% were injection drug users and 94% were receiving antiretrovirals; mean CD4 cell count, 554 cells/microL; 72% with plasma HIV RNA level of <50 copies/mL) were analyzed. The mean alanine aminotransferase level was 68 IU/L, and the mean plasma HCV RNA level was 5.9 log IU/mL. HCV genotype distribution was as follows: genotype 1, 60% of patients; genotype 2, 2%; genotype 3, 26%; and genotype 4, 12%. Overall, 164 (58%) of the patients had scores indicating advanced liver fibrosis (F2-F4), as determined using elastometry. In the univariate and multivariate analyses, respectively, a significant odds ratio (OR) for score F2-F4 was found for HCV genotype 3, compared with the other genotypes (OR, 1.9 [95% confidence interval {CI}, 1.1-3.4] vs. 4.3 [95% CI, 1.4-13.3]); for older age (OR, 1.1 [95% CI, 1.03-1.17] vs. 1.1 [95% CI, 1.01-1.25]); and for elevated alanine aminotransferase levels (OR, 1.02 [95% CI, 1.01-1.03] vs. 1.03 [95% CI, 1.01-1.04]). Although patients with HCV genotype 1 had higher mean serum HCV RNA levels than did those with HCV genotype 3 (6.1 log IU/mL vs. 5.7 log IU/mL; P=.01), patients with HCV genotype 3 tended to have F2-F4 scores more frequently than did those with HCV genotype 1 (69% vs. 58%; P = not significant).

CONCLUSIONS

HCV genotype 3, older age, and elevated alanine aminotransferase levels are independent predictors of advanced liver fibrosis in HCV-HIV-coinfected patients.

Hepatitis C viral load, genotype and histological severity in patients with bleeding disorders

We report the relationship between hepatitis C virus (HCV) titre, liver histology and HCV genotype in patients with bleeding disorders. One hundred and thirty-two RIBA-2-positive patients, including 56 who were also HIV positive, were identified at our centre. Fifty of these patients, including nine who were HIV infected, underwent percutaneous liver biopsy. Liver histology was assessed using a modified histological activity index (HAI). Qualitative serum HCV PCR was positive in 87 (87%) of the 101 patients tested including 43 of 50 biopsied patients. HCV RNA titres, measured by quantitative PCR, were significantly higher in HIV-positive patients compared with HIV-negative patients (P < 0.05) but were not related to HAI, mean factor concentrate usage, duration of HCV infection or HCV genotype. There was no relationship between HCV genotype and HAI. Qualitative HCV PCR was positive in 30 of 43 liver biopsies tested. Biopsy PCR-positive and -negative cohorts were not distinguished by HAI or serum HCV titre. We conclude that although serum HCV PCR is useful in confirming the presence of HCV infection in patients with bleeding disorders, little meaningful information concerning the severity of the disease can be obtained from serum HCV quantification.