Responder Interferon λ Genotypes Are Associated With Higher Risk of Liver Fibrosis in HIV-Hepatitis C Virus Coinfection

Interferon-λ rs12979860 genotype association with liver fibrosis in chronic hepatitis C (CHC) patients in the Pakistani population

Risk and progression of liver fibrosis and cirrhosis in chronic hepatitis C (CHC) patients is significantly influenced by host genetic factors in a polygenic manner. The rs12979860 genetic polymorphism in the interferon-λ3-interferon-λ4 (IFNL3-IFNL4) region has been found to be a major determinant of hepatic inflammatory and fibrotic progression in CHC patients of mainly Caucasian origin; however, it is not known if this association applies to other ethnicities, including Pakistani CHC patients. Here, we genotyped IFNL3-IFNL4 rs12979860 genetic variants in a sample set of 502 Pakistani patients with CHC and used logistic regression analysis to determine its association with the risk and progression of HCV-related fibrosis and cirrhosis. We demonstrate that the rs12979860 major (CC) genotype, despite not determining the risk of stage-specific hepatic fibrosis independently, is associated with a marginally significant risk of liver cirrhosis (OR: 1.64, p = 0.049) after an adjustment for age, gender, body mass index, HCV viral load, and liver enzymes. In a subgroup of CHC patients with sustained ALT levels of <60 IU/L, a more pronounced impact of the IFNL3-IFNL4 rs12979860 major (CC) genotype on advanced liver fibrosis (OR: 4.99, p = 0.017) and cirrhosis (OR: 3.34, p = 0.005) was seen. The present study suggests that IFNL3-IFNL4 rs12979860 polymorphism may also be a significant predictor of hepatic fibrosis and cirrhosis in Pakistani CHC patients, especially in those with normal or near-normal liver enzyme levels.

Insights Into the Pathophysiology of Liver Disease in HCV/HIV: Does it End With HCV Cure?

HCV-HIV coinfected patients exhibit rapid progression of liver damage relative to HCV monoinfected patients. The availability of new directly acting antiviral agents has dramatically improved outcomes for coinfected patients as sustained virologic response rates now exceed 95% and fibrosis-related parameters are improved. Nevertheless, coinfected patients still have a higher mortality risk and more severe hepatocellular carcinoma compared to HCV monoinfected patients, implying the existence of pathways unique to people living with HIV that continue to promote accelerated liver disease. In this article, we review the pathobiology of liver disease in HCV-HIV coinfected patients in the directly acting antiviral era and explore the mechanisms through which HIV itself induces liver damage. Since liver disease is one of the leading causes of non-AIDS-related mortality in HIV-positive patients, enhancing our understanding of HIV-associated fibrotic pathways will remain important for new diagnostic and therapeutic strategies to slow or reverse liver disease progression, even after HCV cure.

Pharmacogenetics and the treatment of HIV-/HCV-coinfected patients

This review will summarize the role of pharmacogenetics in the natural history of hepatitis C, particularly in patients with HIV/HCV and will take the perspective of pharmacogenetics and its influence on the response to antiviral therapy and the susceptibility to develop adverse effects. This review will also devote a section to host genetics in other clinical situations, such as disease progression and acute HCV infection, which may determine whether treatment of HIV-/HCV-coinfected patients is implemented or deferred.

Impact of PNPLA3 and IFNL3 polymorphisms on hepatic steatosis in Asian patients with chronic hepatitis C

BACKGROUND AND AIMS

A recent meta-analysis revealed that the genotype PNPLA3 rs738409 GG is associated with a higher risk of hepatic steatosis (HS) in Caucasian patients with chronic hepatitis C (CHC). However, controversial results were found regarding Asian populations. Furthermore, previous studies have shown a negative association between interferon lambda 3 (IFNL3) rs12979860 CC and HS in Caucasian CHC patients, but there have been no reports indicating any such association in Asian populations. In this study, then, we investigated the association of PNPLA3 and IFNL3 polymorphisms with HS in Asian CHC patients.

METHODS

We enrolled consecutive CHC patients who underwent liver biopsy prior to antiviral therapy. We excluded those patients with decompensated liver disease, any co-existing chronic liver disease, or HIV or HBV co-infection.

RESULTS

1080 CHC patients were enrolled, and HS was found in 453 (41.9%) patients. The frequency distribution of the G allele was significantly associated with HS (P<0.001), and this conferred a higher risk to G allele homozygotes (OR: 2.06, 95% CI: 1.46-2.88, P <0.001) than to G allele carriers (OR: 1.98, 95% CI: 1.52-2.58, P<0.001). There was a borderline significant difference in the prevalence of HS in rs12979860 CC versus non-CC (40.8% versus 49.3%, P = 0.059). After adjustment for age, sex, body mass index, diabetes, and excessive alcohol intake, the rs738409 G allele homozygote carriers still carried a higher risk for HS (OR: 1.93, 95% CI: 1.35-2.77, P = 0.003).

CONCLUSION

The PNPLA3 rs738409 GG genotype is positively associated with HS, while the IFNL3 rs 12979860 CC genotype may be negatively associated with HS, in Asian CHC patients.

A prognostic model for development of significant liver fibrosis in HIV-hepatitis C co-infection

BACKGROUND

Liver fibrosis progresses rapidly in HIV-Hepatitis C virus (HCV) co-infected individuals partially due to heightened inflammation. Immune markers targeting stages of fibrogenesis could aid in prognosis of fibrosis.

METHODS

A case-cohort study was nested in the prospective Canadian Co-infection Cohort (n = 1119). HCV RNA positive individuals without fibrosis, end-stage liver disease or chronic Hepatitis B at baseline (n = 679) were eligible. A random subcohort (n = 236) was selected from those eligible. Pro-fibrogenic markers and Interferon Lambda (IFNL) rs8099917 genotype were measured from first available sample in all fibrosis cases (APRI ≥ 1.5 during follow-up) and the subcohort. We used Cox proportional hazards and compared Model 1 (selected clinical predictors only) to Model 2 (Model 1 plus selected markers) for predicting 3-year risk of liver fibrosis using weighted Harrell's C and Net Reclassification Improvement indices.

RESULTS

113 individuals developed significant liver fibrosis over 1300 person-years (8.63 per 100 person-years 95% CI: 7.08, 10.60). Model 1 (age, sex, current alcohol use, HIV RNA, baseline APRI, HCV genotype) was nested in model 2, which also included IFNL genotype and IL-8, sICAM-1, RANTES, hsCRP, and sCD14. The C indexes (95% CI) for model 1 vs. model 2 were 0.720 (0.649, 0.791) and 0.756 (0.688, 0.825), respectively. Model 2 classified risk more appropriately (overall net reclassification improvement, p<0.05).

CONCLUSIONS

Including IFNL genotype and inflammatory markers IL-8, sICAM-1, RANTES, hs-CRP, and sCD14 enabled better prediction of the 3-year risk of significant liver fibrosis over clinical predictors alone. Whether this modest improvement in prediction justifies their additional cost requires further cost-benefit analyses.

Update in HIV-hepatitis C virus coinfection in the direct acting antiviral era

PURPOSE OF REVIEW

Availability of direct acting antivirals (DAAs) that demonstrate remarkable clinical efficacy and safety has revolutionized the ability to treat chronic infection with hepatitis C virus (HCV). An equal measure of clinical success has now been achieved in persons coinfected with HCV and the HIV, a historically harder to cure cohort with interferon-based therapy. Global goals include identifying all HIV-HCV-infected persons, gaining access to DAA therapy, preventing de novo and reinfection, and managing the sequelae of chronic infection. This review will discuss advances in the field of HIV-HCV coinfection reported during the last 18 months, and will suggest areas for future investigation.

RECENT FINDINGS

An expanding body of literature has enhanced our understanding of the clinical and epidemiologic issues surrounding HIV-HCV coinfection. DAA therapy for HCV is highly efficacious in HIV-HCV-coinfected persons if drug-drug interactions are appropriately considered.

SUMMARY

Eradicating HCV infection in persons with HIV coinfection can be achieved safely and effectively with available DAAs. Economic and social approaches to enable access and delivery of curative HCV therapy to HIV-infected persons require continued research and resource allocation.

Targeting IFN-λ: therapeutic implications

INTRODUCTION

Type-III interferons (IFN-λ), the most recently discovered family of IFNs, shares common features with other family members, but also has many distinctive activities. IFN-λ uniquely has a different receptor complex, and a more focused pattern of tissue expression and signaling effects, from other classes of IFNs. Multiple genome-wide association studies (GWAS) and subsequent validation reports suggest a pivotal role for polymorphisms near the IFNL3 gene in hepatitis C clearance and control, as also for several other epithelial cell tropic viruses. Apart from its antiviral activity, IFN-λ possesses anti-tumor, immune-inflammatory and homeostatic functions. The overlapping effects of IFN-λ with type I IFN, with a restricted tissue expression pattern renders IFN-λ an attractive therapeutic target for viral infection, cancer and autoimmune diseases, with limited side effects. Areas covered: This review will summarize the current and future therapeutic opportunities offered by this most recently discovered family of interferons. Expert opinion: Our knowledge on IFN-λ is rapidly expanding. Though there are many remaining questions and challenges that require elucidation, the unique characteristics of IFN-λ increases enthusiasm that multiple therapeutic options will emerge.