λ‐Interferons and the single nucleotide polymorphisms: A milestone to tailor‐made therapy for chronic hepatitis C

Type III interferons (IFN) (IFN‐λ1, ‐λ2, ‐λ3/interleukin [IL]‐29, ‐28A, ‐28B) are cytokines with type I IFN‐like antiviral activities. Most cells have expressed both type I and III IFN following Toll‐like receptor (TLR) stimulation or viral infection, whereas the ability of cells to respond to IFN‐λ was restricted to a specific subset of cells. It was reported that signal transduction pathway of IFN‐λ was similar to that of IFN‐α/β although a receptor adapted by IFN‐λ were distinct from that of IFN‐α/β. However, the clinical significance and the role of each IFN‐λ were unclear. Recent genome‐wide association studies (GWAS) of the human whole genome revealed several single nucleotide polymorphism sites (SNP) strongly associated with the response to pegylated IFN‐α (PEG‐IFN) plus ribavirin (RBV) treatment in chronic hepatitis C patients. The SNP, which are located near the IL‐28B gene of chromosome 19, were discovered simultaneously by three independent studies opening a new prospective in hepatitis C research. The present review highlights significant insights that can be derived from the GWAS approach, and summarizes current knowledge of in vitro and in vivo study on the role of IFN‐λ in antiviral effect.     

IL‐28B (IFN‐λ3) and IFN‐α synergistically inhibit HCV replication

Genetic variation in the IL‐28B (interleukin‐28B; interferon lambda 3) region has been associated with sustained virological response (SVR) rates in patients with chronic hepatitis C treated with peginterferon‐α and ribavirin. However, the mechanisms by which polymorphisms in the IL‐28B gene region affect host antiviral responses are not well understood. Using the HCV 1b and 2a replicon system, we compared the effects of IFN‐λs and IFN‐α on HCV RNA replication. The anti‐HCV effect of IFN‐λ3 and IFN‐α in combination was also assessed. Changes in gene expression induced by IFN‐λ3 and IFN‐α were compared using cDNA microarray analysis. IFN‐λs at concentrations of 1 ng/mL or more exhibited concentration‐ and time‐dependent HCV inhibition. In combination, IFN‐λ3 and IFN‐α had a synergistic anti‐HCV effect; however , no synergistic enhancement was observed for interferon‐stimulated response element (ISRE) activity or upregulation of interferon ‐ stimulated genes (ISGs). With respect to the time course of ISG upregulation, the peak of IFN‐λ3‐induced gene expression occurred later and lasted longer than that induced by IFN‐α. In addition, although the genes upregulated by IFN‐α and IFN‐λ3 were similar to microarray analysis, interferon‐stimulated gene expression appeared early and was prolonged by combined administration of these two IFNs. In conclusion, IFN‐α and IFN‐λ3 in combination showed synergistic anti‐HCV activity in vitro. Differences in time‐dependent upregulation of these genes might contribute to the synergistic antiviral activity.     

HCV dsRNA-Activated Macrophages Inhibit HCV Replication in Hepatocytes

Background:

Macrophages play critical roles in innate immune response in the liver. Whether macrophages participate in liver innate immunity against HCV replication is poorly understood

Objectives:

The aim of this study was to investigate the role of macrophages in liver innate immunity against HCV replication.

Materials and Methods:

Freshly isolated monocytes were purified from peripheral blood of healthy adult donors. Macrophages refer to 7-day-cultured monocytes in vitro. A hepatoma cell line (Huh7) was infected with HCV JFH-1 to generate in vitro HCV infectious system. RT-PCR was used to determine HCV RNA and mRNA levels of genes expression. ELISA was used to measure the protein level of interferon-α (IFN-α) and western blot was used to determine protein expression level of Toll-like receptor 3 (TLR3).

Results:

HCV dsRNA induced the expression of type I IFN (IFN-α/β) in monocyte-derived macrophages. HCV dsRNA also induced the expression of TLR3 and IFN regulatory factor-7 (IRF-7), the key regulators of the IFN signaling pathway. When HCV JFH-1-infected Huh7 cells were co-cultured with macrophages activated with HCV dsRNA or incubated in media conditioned with supernatant (SN) from HCV dsRNA-activated macrophages, HCV replication was significantly suppressed. This macrophage SN action on HCV inhibition was mediated through type I IFN, which was evidenced by the observation that antibody to type I IFN receptor could neutralize the macrophages-mediated anti-HCV effect. The role of type I IFN in macrophages-mediated anti-HCV activity is further supported by the observation that HCV dsRNA-activated macrophages SN treatment induced the expression of several IFN-stimulated genes (ISGs), ISG15, ISG56, OAS-1, OAS-2, MxA and Viperin in HCV-infected Huh7 cells.

Conclusions:

Macrophages may play an important role in liver innate immunity against HCV replication through a type I IFN-dependent mechanism.     

Development of specific and quantitative real‐time detection PCR and immunoassays for λ3‐interferon

Aim: Single nucleotide polymorphisms (SNP) around interferon (IFN)‐λ3 have been associated with the response to pegylated IFN‐α treatment for chronic hepatitis C. Specific quantification methods for IFN‐λ3 are required to facilitate clinical and basic study. Methods: Gene‐specific primers and probes for IFN‐λ1, 2 and 3 were designed for real‐time detection PCR (RTD–PCR). Dynamic range and specificity were examined using specific cDNA clones. Total RNA from hematopoietic and hepatocellular carcinoma cell lines was prepared for RTD–PCR. Monoclonal antibodies were developed for the IFN‐λ3‐specific immunoassays. The immunoassays were assessed by measuring IFN‐λ3 in serum and plasma. Results: The RTD–PCR had a broad detection range (10–10⁷ copies/assay) with high specificity (～10⁷‐fold specificity). Distinct expression profiles were observed in several cell lines. Hematopoietic cell lines expressed high levels of IFN‐λ compared with hepatocellular carcinoma cells, and Sendai virus infection induced strong expression of IFN‐λ. The developed chemiluminescence enzyme immunoassays (CLEIA) detected 0.1 pg/mL of IFN‐λ3 and showed a wide detection range of 0.1–10 000 pg/mL with little or no cross‐reactivity to IFN‐λ1 or IFN‐λ2. IFN‐λ3 could be detected in all the serum and plasma samples by CLEIA, with median concentrations of 0.92 and 0.86 pg/mL, respectively. Conclusion: Our newly developed RTD–PCR and CLEIA assays will be valuable tools for investigating the distribution and functions of IFN‐λ3, which is predicted to be a marker for predicting outcome of therapy for hepatitis C or other virus diseases.     

MicroRNA‐155 controls Toll‐like receptor 3‐ and hepatitis C virus‐induced immune responses in the liver

The hepatitis C virus (HCV) establishes persistent infections despite strong activation of the innate immune system through TLR3 and other sensors. Therefore, we analysed regulatory mechanisms of TLR3‐induced immune responses in nonparenchymal liver cells (NPCs). Effects of Interleukin‐10 (IL‐10), transforming growth factor beta (TGF‐β) and immunoregulatory miR‐155 on poly I:C‐activated murine (C57BL/6) Kupffer cells (KC) and sinusoidal endothelial cells (LSEC) were assessed in vitro. NPCs were assayed for inflammatory and antiviral cytokines and T‐cell (Balb/c)‐activating factors. Gene expression of miR‐155, IL‐10, TGF‐β and interferon sensitive genes (ISGs) in biopsies of patients with HCV was determined by qrt‐PCR. TLR3‐induced antiviral activity in murine NPCs was potently suppressed by IL‐10 and TGF‐β which correlated with decreased TLR3 expression and inhibition of NF‐κB and IRF‐3 activation. T‐cell activation, induced by TLR3‐activated NPCs, was also suppressed by IL‐10 and TGF‐β, which was associated with a down‐regulation of CD80 and CD86. Pretreatment with IL‐10 or TGF‐β suppressed TLR3‐induced miR‐155 expression, which itself positively regulated poly I:C‐mediated immune responses, thus counteracting IL‐10 or TGF‐β‐induced immunosuppression. In addition, hepatic expression of miR‐155 was elevated in chronically infected patients with HCV, was associated with an IL‐28B SNP (rs12979860) and was inversely correlated with HCV serum load and ISG expression levels. As miR‐155 is a key regulator of anti‐inflammatory mechanisms that control innate and adaptive hepatic immune responses during HCV infection, miR‐155 based therapies may represent a novel mechanism to control HCV in the future.     

Long‐term stimulation of Toll‐like receptor 3 in primary human hepatocytes leads to sensitization for antiviral responses induced by poly I:C treatment

Chronic hepatitis C infection is associated with increased expression of interferon‐sensitive genes (ISGs) in the liver, which is, paradoxically, correlated with the nonresponse to interferon (IFN)‐based therapies. In the present study PHHs were isolated from HCV‐infected or uninfected patients and stimulated with the TLR1‐9 ligands for 6–24 h. Expression of cytokines and ISGs was determined by ELISA and qRT‐PCR. A comparative analysis was performed for TLR3 signalling, which was also correlated with single nucleotide polymorphisms (SNPs) related to HCV pathogenesis. TLR‐activated PHHs produced pro‐inflammatory and anti‐inflammatory cytokines, whereas IFNs were exclusively induced by TLR3 stimulation. Here, IL‐29 and IL‐28A were significantly highly expressed than IFN‐α and IFN‐β. TLR3‐induced IFN response was enhanced in hepatocytes isolated from patients with HCV infection. This hyper‐responsiveness could be mimicked in naïve PHHs consistently stimulated with low dose of poly I:C, but not Guardiquimod. The higher responsiveness in PHH isolated from HCV‐infected patients could be partially explained by higher frequencies of unfavourable SNP alleles of different SNPs associated with HCV progression and treatment outcome. These data suggest that durable activation of TLR3 but not TLR7, by low doses of viral replicative intermediates, increases the sensitivity to viral invasion. These findings shed new light on the relevance of TLR3 in the pathogenesis of HCV and may provide a possible explanation for the increased ISG expression during chronic HCV infection, the so‐called IFN paradox.     

Toll‐IL1 receptor‐mediated innate immune responses vary across HBV genotype and predict treatment response to pegylated‐IFN in HBeAg‐positive CHB patients

Patients with hepatitis B e antigen (HBeAg)‐positive chronic hepatitis B (CHB) have suppressed TLR2 expression, function and cytokine production. The aim of this study was to explore the importance of hepatitis B virus (HBV) genotype in innate immune responses and investigate whether Toll‐like receptor (TLR) expression/function has potential roles as predictive biomarkers of successful therapy with pegylated interferon (Peg‐IFN) therapy of HBeAg seroconversion in HBeAg‐positive patients. We showed that as early as 4 weeks after initiation of Peg‐IFN, future HBeAg seroconverters had significantly elevated levels of TLR2 expression on monocytes. TLR2‐associated IL‐6 production at baseline and week 4 of therapy and TLR4 IL‐6 production at week 4 were also markedly elevated in HBeAg seroconverters. HBV genotype also influenced treatment response, with genotypes A and B more likely to seroconvert than D. We were able to demonstrate that these differences were due in part to the interaction of the specific HBeAg proteins with TLR pathway adaptor molecules, and these interactions were genotype dependent. HBeAg‐mediated modulation of TLR signalling was also observed in Huh7 cells, following stimulation with Pam3Cys. Importantly, the addition of IFN‐α to TLR2‐stimulated cells cotransfected with an HBeAg expression plasmid reversed HBeAg‐mediated suppression of hepatocytes. These findings demonstrate that patients with an activated inflammatory response are much more likely to respond to IFN therapy, with TLR responses showing promise as potential biomarkers of HBeAg seroconversion in this setting. Furthermore, our findings suggest there is differential genotype‐specific HBeAg suppression of innate signalling pathways which may account for some of the clinical differences observed across the CHB spectrum.     

Hepatic Toll‐like receptor 3 expression in chronic hepatitis C genotype 1 correlates with treatment response to peginterferon plus ribavirin

Summary. Recent studies have shown that enhanced hepatic expression of several innate immune genes predicts non‐response to 48 weeks of peginterferon plus ribavirin in chronic hepatitis C genotype 1. This study aimed to further address how gene expression of TLR3/RIG‐I signalling correlates with the outcome of the 72‐week extended treatment regimen. Relative hepatic mRNA expression and copy numbers of positive‐ and negative‐strand hepatitis C virus (HCV) RNA were determined by real‐time PCR in 49 patients. Then, a 48‐week peginterferon‐α2b plus ribavirin treatment was commenced and extended to 72 weeks in cases of HCV RNA clearance after week 12. High rate of sustained virologic response was seen both in patients with early HCV clearance (85% [11/13]) and slow virologic responders (85% [11/13]) (per protocol analysis). The response was associated with low TLR3 expression (median, 0.9; range, 0–4.2 vs median, 1.9; range, 0.4–4.9; P = 0.004) but had no relation to the expression of TRIF (P = 0.315), RIG‐I (P = 0.953), IPS‐1 (P = 0.425), IRF3 (P = 0.329) and interferon‐β (P = 0.584). ROC curve analysis identified TLR3 expression of <1.5 as the best cut‐off for predicting response (positive and negative predictive values, 89% [16/18] and 70% [14/20], respectively). The expression was not affected by HCV replication but was higher in female patients (P = 0.043). Multivariate analysis showed TLR3 to be a single baseline predictor (odds ratio 18.5 [95% CI 3.2–111], P = 0.001). Low hepatic TLR3 expression is a novel predictor of response to peginterferon plus ribavirin in genotype 1 patients.     

Differential expression of innate immune response genes in clinical phases of chronic hepatitis B infection

We investigated innate immune gene expression in clinical phases of chronic hepatitis B infection, including immune tolerant (IT), immune active (IA), inactive carrier (IC) and hepatitis B e antigen (HBeAg)‐negative phases, as well as healthy controls. Expression levels of interferon types I, II and III, their receptor subunits, IRFs, TLRs and other IFN‐induced genes in peripheral blood mononuclear cells were compared. Forty HBsAg‐positive treatment‐naïve subjects without co‐infection with HIV, HCV or HDV were enrolled. To complement the viral load, the expression levels of 37 innate immune genes were measured by qPCR. The highest response of the innate immune system was observed in the IT and HBeAg‐negative phases, and the IC phase had the lowest response; 31 of the 37 studied genes reached their maximum mRNA expression levels in the IT and HBeAg‐negative phases, and the minimum expression levels of 23 genes were found in the IC phase. The highest mRNA expression levels of IFNs, IFN receptor subunits, IRFs and TLRs genes in all clinical phases were IFN‐λ2 and 3, IFN‐γR2, IRF7 and TLR7, and the lowest levels of mRNA expression were observed for IFN‐α, IFN‐λR1, IRF8 and TLR2. We conclude that innate immune response genes are expressed differentially among chronic HBV phases, and this difference may help to develop new precise and noninvasive methods to determine the progression of disease in chronic HBV patients.     

MicroRNA‐130a inhibits HCV replication by restoring the innate immune response

Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis and hepatocellular carcinoma. Currently pegylated interferon (IFN) combined with ribavirin remains the best therapeutic approach, although patients infected with HCV genotype I may benefit from adding protease inhibitors as ‘triple therapy’. MicroRNAs (miRNAs) are endogenous small noncoding RNAs that regulate gene expression and have recently been shown to play an important role in human innate immune response and as an antiviral in chimpanzees. We studied the effect of miR‐130a on the HCV replication. We found that miR‐130a significantly inhibits HCV replication in both HCV replicon and J6‐/JFH1‐infected cells. Over expression of miR‐130a upregulated the expression of type I IFN (IFN‐α/IFN ‐β), ISG15, USP18 and MxA, which are involved in innate immune response and decreased expression of miR‐122, a well‐defined miRNA promoting HCV production. In conclusion, miR‐130a inhibits HCV replication/production by restoring host innate immune responses and/or downregulating pro‐HCV miR‐122. miR‐130a might be a potential drug target by modulating host innate immune responses to combat HCV infection.     

Decreased IFNγ production correlates with diminished production of cytokines by dendritic cells in patients infected with hepatitis C virus and receiving therapy

Summary. Toll‐like receptor (TLR) expression and the signalling pathways that lead to the production of accessory cytokines by antigen‐presenting cells (APCs) both have potential to limit T‐cell responses to viral antigens. Here, expression of TLR and retinoic acid inducible gene I (RIG‐I) and responses evoked through these proteins were evaluated in patients chronically infected with HCV, before and during pegylated interferon‐α (IFNα) and ribavirin therapy. Expression of TLR2, 3, 4, 7, 9 and RIG‐I on APCs and cytokine production by DCs were measured by flow cytometry. Production of IL‐12 by myeloid dendritic cells (mDCs), IFNα by plasmacytoid cells (pDCs) and IFNγ by peripheral blood mononuclear cells was measured after stimulation with TLR ligands. IFNγ ELISpot responses to HCV and CMV antigens declined on therapy. TLR and RIG‐I expression on mDCs, pDCs, B cells and monocytes was either similar or higher in patients than that in controls and generally increased during therapy. Therapy impaired IL‐12 and IFNα production by DCs and reduced production of IFNγ by PBMCs after stimulation with ligands for TLR3, TLR7/8, TLR9 and RIG‐I. This was independent of whether patients attained a sustained virological response. HCV disease and interferon‐based therapy reduced IFN‐γ responses to HCV antigens and TLR agonists. This was not accompanied by reduced expression of pertinent TLR but correlated with diminished production of co‐stimulatory cytokines by DCs stimulated via TLR.     

Disparity of basal and therapeutically activated interferon signalling in constraining hepatitis E virus infection

Hepatitis E virus (HEV) represents one of the foremost causes of acute hepatitis globally. Although there is no proven medication for hepatitis E, pegylated interferon‐α (IFN‐α) has been used as off‐label drug for treating HEV. However, the efficacy and molecular mechanisms of how IFN signalling interacts with HEV remain undefined. As IFN‐α has been approved for treating chronic hepatitis C (HCV) for decades and the role of interferon signalling has been well studied in HCV infection, this study aimed to comprehensively investigate virus–host interactions in HEV infection with focusing on the IFN signalling, in comparison with HCV infection. A comprehensive screen of human cytokines and chemokines revealed that IFN‐α was the sole humoral factor inhibiting HEV replication. IFN‐α treatment exerted a rapid and potent antiviral activity against HCV, whereas it had moderate and delayed anti‐HEV effects in vitro and in patients. Surprisingly, blocking the basal IFN pathway by inhibiting JAK1 to phosphorylate STAT1 has resulted in drastic facilitation of HEV, but not HCV infection. Gene silencing of the key components of JAK‐STAT cascade of the IFN signalling, including JAK1, STAT1 and interferon regulatory factor 9 (IRF9), stimulated HEV infection. In conclusion, compared to HCV, HEV is less sensitive to IFN treatment. In contrast, the basal IFN cascade could effectively restrict HEV infection. This bears significant implications in management of HEV patients and future therapeutic development.     

Tamoxifen alleviates hepatitis C virus‐induced inhibition of both toll‐like receptor 7 and JAK‐STAT signalling pathways in PBMCs of infected Egyptian females

Summary. Hepatitis C virus (HCV) is a major health concern in Egypt being highly prevalent among Egyptians. The two genders experience different responses to HCV infection and show variations in response to interferon (IFN)‐based therapy that may be attributed to sex hormones. We previously demonstrated the suppressive effect of 17β‐estradiol (E2) on the expression of the IFN‐stimulated gene MxA in HCV‐infected peripheral blood mononuclear cells (PBMCs). The selective oestrogen receptor (ER) modulator Tamoxifen has been shown to have an antiviral effect against HCV, but its effect on the host immune response is unknown. We investigated the effect of Tamoxifen on the IFN signalling pathways in PBMCs of HCV‐infected Egyptian females. We pooled PBMCs and treated then with exogenous interferon alpha (IFNα) or the TLR7 ligand, Imiquimod, and quantified the relative expressions of MxA using RTqPCR. Studies were performed with and without Tamoxifen pretreatment. Pretreatment with Tamoxifen reversed the suppressive effect of E2 on the JAK‐STAT pathway in IFNα‐treated PBMCs as indicated by a significant increase in MxA expression (P = 0.05*). Tamoxifen pretreatment also significantly upregulated MxA expression in Imiquimod‐treated PBMCs (P = 0.0011**), an effect not ascribed to ER blocking nor to an upregulation in TLR7 expression because Tamoxifen showed no potentiating effect on the expression of the receptor. In conclusion, our findings reveal that Tamoxifen has immunomodulatory effects whereby it enhances the host IFN signalling pathways during HCV infection.     

Value of IL28B genotyping in patients with HCV‐related mixed cryoglobulinemia: results of a large,prospective study

HCV‐related mixed cryoglobulinemia (MC) is characterized by clonal expansion of B cells producing a polyreactive natural antibody (rheumatoid factor) and interferon (IFN)‐based therapy is the first therapeutic option in mild‐moderate MC. Single nucleotide polymorphisms (SNPs) proximal to genes involved in the innate response (IL28B/IFN‐λ gene family) are strongly associated with spontaneous and IFN‐induced viral clearance in hepatitis C, but no data exist about their role in HCV‐positive MC. A large cohort of patients with HCV and MC was studied to evaluate the influence of IL28B genotype on the response to treatment and/or the evolution to MC of HCV infection. The rs12979860/rs8099917 IL28B polymorphisms were analysed in 481 consecutive HCV‐positive subjects (250 with MC and 231 without MC, as controls) using real‐time PCR and direct sequencing. Hundred and fifteen HCV patients with MC received standard anti‐HCV therapy, and the results were evaluated according to the IL28B SNP distribution. Similar IL28B SNPs allele frequencies were recorded for patients and controls. IL28B major allele homozygosis (for both SNPs tested) was tightly correlated with virological and clinical response (P = 0.002). A statistically significant association was limited to ‘difficult‐to‐treat’ (G1/4) HCV genotypes. The IL28B genotype was a strong independent predictor of response (P = 0.007, OR 6.06; CI 1.65–22.22). The IL28B genotype was confirmed to be a useful predictor of response to IFN‐based therapy in patients with HCV and MC. The very close correlation between IL28B SNP distribution, virological and clinical response definitively confirmed the key role played by HCV in MC. Conversely, the IL28B genotype does not seem to influence the evolution to MC.     

Increased apoptosis in HepG2.2.15 cells with hepatitis B virus expression by synergistic induction of interferon‐γ and tumour necrosis factor‐α

Background: Interferon‐γ (IFN‐γ) and tumour necrosis factor‐α (TNF‐α) were thought to be important immune mediators in host defence against hepatitis B virus (HBV) infection. Aims: To examine the synergistic effect of IFN‐γ and TNF‐α on HBV‐expressing HepG2.2.15 cells and its potential mechanisms. Methods: Cell viability was quantitatively measured by 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyl tetrazolium bromide assay. Cell morphology was captured using light microscopy. The typical DNA ladder test was performed using agarose gel electrophoresis. HBsAg and HBeAg titre changes were quantified by the enzyme‐linked immunosorbent assay method. Gene expression was analysed using cDNA macroarrays. Results: Interferon‐γ (1000 U/ml) alone or combined with TNF‐α (5 ng/ml) treatment resulted in apoptosis in HepG2.2.15 cells, but no significant apoptosis in the parent non‐virus expressing HepG2 cells. IFN‐γ‐ and TNF‐α‐mediated apoptosis was reduced by lamivudine treatment in HepG2.2.15 cells. IFN‐γ combined with TNF‐α reduced the titre of hepatitis B surface antigen and hepatitis B e antigen in the HepG2.2.15 cell line. For apoptosis‐related gene changes, IFN regulatory factor 1 (IRF‐1) (12.2‐fold), c‐myc (V00568 4.7‐fold, L00058 2.4‐fold) and caspase 7 (2.3‐fold) genes were upregulated in the combination treatment group. Conclusion: Interferon‐γ and TNF‐α play a role in the cell death of HBV‐expressing HepG2.2.15 cells. Expression of HBV leads to IFN‐γ‐ and TNF‐α‐mediated apoptosis in the cells. Increased IRF‐1, c‐myc and caspase 7 gene expression may be responsible for the synergistic induction of apoptosis by IFN‐γ and TNF‐α.     

Association of IFNL3 and IFNL4 polymorphisms with liver‐related mortality in a multiracial cohort of HIV/HCV‐coinfected women

African Americans coinfected with HIV and hepatitis C virus (HCV) have lower liver‐related mortality than Caucasians and Hispanics. While genetic polymorphisms near the IFNL3 and IFNL4 genes explain a significant fraction of racial differences in several HCV‐related outcomes, the impact of these variants on liver‐related mortality has not been investigated. We conducted a cohort study of HIV/HCV‐coinfected women followed in the multicentre, NIH‐funded Women's Interagency HIV Study (WIHS) to investigate whether 10 polymorphisms spanning the IFN‐λ region were associated with liver‐related mortality by dominant, recessive or additive genetic models. We also considered whether these polymorphisms contributed to previously reported differences in liver‐related death by race/ethnicity (ascertained by self‐report and ancestry informative markers). Among 794 coinfected women, there were 471 deaths including 55 liver‐related deaths during up to 18 years of follow‐up. On adjusted analysis, rs12980275 GG genotype compared to AG+AA hazards ratios [(HR) 0.36, 95% CI 0.14–0.90, P = 0.029] and rs8109886 AA genotype compared to CC+AC (HR 0.67, 95% CI 0.45–0.99, P = 0.047) were most strongly associated with liver‐related death although these associations were no longer significant after adjusting for race/ethnicity (HR 0.41, 95% CI 0.16–1.04, P = 0.060 and HR 0.78, 95% CI 0.51–1.19, P = 0.25, respectively). African American women had persistently lower liver‐related death independent of IFN‐λ variants (HRs ≤ 0.44, P values ≤ 0.04). The lower risk of death among African American HIV/HCV‐coinfected women is not explained by genetic variation in the IFN‐λ region suggesting, that other genetic, behavioural and/or environmental factors may contribute to racial/ethnic differences in liver‐related mortality.