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.     

Role of Functional IFNL4, IFNLR1, IFNA,IFNAR2 Polymorphisms in Hepatitis B virus‐related liver disease in Han Chinese population

Recent studies show that variants in some interferon genes together with interferon receptor genes are associated with the outcome of infectious diseases. We examined the association between the risk of hepatitis B virus (HBV)‐related liver disease and the functional polymorphisms within IFNL4, IFNLR1, IFNA1, IFNA2, IFNA5 and IFNAR2 genes (14 loci in all) in a Han Chinese population. A total of 3128 people participated and were divided into 5 groups: healthy controls, natural clearance, chronic hepatitis B(CHB), liver cirrhosis and hepatocellular carcinoma (HCC). Significant associations were observed for 4 variants in IFNAR2, IFNLR1 with HBV infection, and IFNLR1‐rs4649203 was associated with HBV recovery. Moreover, we demonstrated the clear relevance of 5 polymorphisms in IFNA1, IFNA2, IFNL4 with HCC. Three SNPs in IFNL4 gene may be important susceptible factors for the progression of HBV‐related liver disease by trend chi‐square test. The IFNL4 haplotype conformed by rs12971396_G, rs8113007_T and rs7248668A was more frequent in HCC than CHB and LC group. Three polymorphisms in the 5′ region of the IFNL4 gene are associated with the progression of HBV‐related liver disease. IFNA1‐ rs1831583 and IFNA2‐ rs649053 are associated with the development of HCC. IFNLR1‐ rs4649203, rs7525481 are predictors for HBV infection, and rs4649203 is a predictor of spontaneous clearance. IFNAR2 ‐rs1051393, rs12233338 may be predictive markers of HBV infection in the Chinese population.     

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.     

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.     

Induction of interferon‐λ contributes to Toll‐like receptor‐3‐activated hepatic stellate cell–mediated hepatitis C virus inhibition in hepatocytes

There is limited information about the role of hepatic stellate cells (HSC) in liver innate immunity against hepatitis C virus (HCV). We thus examined whether HSC can produce antiviral factors that inhibit HCV replication in human hepatocytes. HSC expressed functional Toll‐like receptor 3 (TLR‐3), which could be activated by its ligand, polyinosine‐polycytidylic acid (poly I:C), leading to the induction of interferon‐λ (IFN‐λ) at both mRNA and protein levels. TLR‐3 signalling of HSC also induced the expression of IFN regulatory factor 7 (IRF‐7), a key regulator of IFN signalling pathway. When HCV JFH‐1‐infected Huh7 cells were co‐cultured with HSC activated with poly I:C or incubated in media conditioned with supernatant (SN) from poly I:C‐activated HSC, HCV replication was significantly suppressed. This HSC SN action on HCV inhibition was mediated through IFN‐λ, which was evidenced by the observation that antibody to IFN‐λ receptors could neutralize the HSC‐mediated anti‐HCV effect. The role of IFN‐λ in HSC‐mediated anti‐HCV activity is further supported by the observation that HSC SN treatment induced the expression of IRF‐7 and IFN‐stimulated genes (ISGs), OAS‐1 and MxA in HCV‐infected Huh7 cells. These observations indicate that HSC may be a key regulatory bystander, participating in liver innate immunity against HCV infection using an IFN‐λ‐dependent mechanism.     

Hepatitis B virus‐induced hepatocellular carcinoma: functional roles of MICA variants

Hepatitis B virus infection is a high‐risk factor for hepatocellular carcinoma. The human major histocompatibility complex class I chain‐related gene A (MICA) is a ligand of the NKG2D receptor that modulates the NK and T‐cell‐mediated immune responses and is associated with several diseases. This study determined the effects of MICA polymorphisms during HBV infection and HBV‐induced HCC. We conducted a case–controlled study in a Vietnamese cohort and genotyped ten functional MICA polymorphisms including the microsatellite motif in 552 clinically classified hepatitis B virus patients and 418 healthy controls. The serum soluble MICA levels (sMICA) were correlated with MICA variants and liver enzyme levels. We demonstrated a significant contribution of MICA rs2596542G/A promoter variant and nonsynonymous substitutions MICA‐129Met/Val, MICA‐251Gln/Arg, MICA‐175Gly/Ser, triplet repeat polymorphism and respective haplotypes with HBV‐induced HCC and HBV persistence. The circulating sMICA levels in HBV patient groups were elevated significantly compared with healthy controls. A significant contribution of studied MICA variants to sMICA levels was also observed. The liver enzymes alanine amino transferase (ALT), aspartate transaminase (AST), total bilirubin and direct bilirubin were positively correlated with sMICA levels suggesting sMICA as a biomarker for liver injury. We conclude that MICA polymorphisms play a crucial role in modulating innate immune responses, tumour surveillance and regulate disease susceptibility during HBV infection.     

Long‐term outcome of hepatitis B virus‐related Chronic Hepatitis under protracted nucleos(t)ide analogues

Long‐term outcome of patients with chronic hepatitis B virus (HBV) infection under continuous nucleos(t)ide analogues (NUCs) has been poorly elucidated. We enrolled 121 anti‐HBe‐positive patients into a prospective surveillance programme while on (>36 months) NUCs therapy. HBV‐DNA clearance, add‐on therapy and safety were evaluated. Development of cirrhosis, events of liver decompensation and hepatocellular carcinoma (HCC) during the follow‐up were the main endpoints, as the complication‐free survival. At baseline, 74 patients (61%) had chronic hepatitis, the remainders a cirrhotic liver. HBV‐DNA levels >38 000 IU/mL were discovered in 103 patients. At enrolment, 79 patients were naïve to NUCs treatment. Lamivudine monotherapy (n = 70) or a different NUC (n = 51) was administered. At month 6 of therapy, HBV‐DNA clearance was documented in 88 patients (73%). Treatment schedule was modified in 52 patients due to breakthrough or suboptimal response. During a mean follow‐up of 6 ± 3 years, viral clearance was achieved in the majority of patients. Ten of 74 patients (13.5%) with chronic hepatitis progressed to cirrhosis, 1 patient developed a HCC. In the 47 patients with cirrhosis at presentation, HCC occurred in 14 (30%) and liver decompensation in 5 (11%). The 5 and 10‐year event‐free survivals were, respectively, 89.3% (95% CI, 81.7 ?96.9) and 75.6% (95% CI, 61.5 ?89.7) for patients with chronic hepatitis, and 70.2% (95% CI, 56.3 ?84.1) and 40.4% (95% CI, 16.9 ?63.9) for those with cirrhosis. Protracted, effective treatment with oral NUCs affects the natural history of chronic HBV infection by reducing the incidence of cirrhosis and risk of complications, but does not guarantee against the development of HCC in cirrhosis at presentation.     

HCV RNA decline in chronic HCV genotype 2 and 3 during standard of care treatment according to IL28B polymorphism

The IL28 gene is highly associated with sustained viral response (SVR) in patients infected with genotype 1 after standard of care (SOC) treatment with peg‐IFN and ribavirin. It is also associated with a steeper first phase HCV RNA decline during treatment. In genotype 2 and 3 infections, these correlations are less obvious. We studied the IL28B association to rapid viral response (RVR), SVR, first and second phase HCV RNA decline during treatment in 100 HCV mono‐infected and 13 HCV/HIV co‐infected patients. We found a significantly higher mean baseline HCV RNA level in IL28B SNP CC than non‐CC mono‐infected patients, 6.99 vs 6.30 log₁₀ IU/mL (P = 0.02), and a significantly larger median 1st phase decline in patients with CC than non‐CC genotype, 2.03 vs 1.37 log₁₀ IU/mL, respectively. The overall SVR rate in HCV mono‐infected patients was 87% vs 77% in HCV/HIV co‐infected patients, with no correlation to IL28B SNP. In mono‐infected patients with RVR, the SVR rate was high and independent of IL28B genotype. In mono‐infected patients who failed to achieve RVR who had IL28B CC and non‐CC genotype, 64% and 67% achieved SVR, respectively. In genotype 2 and 3 infected patients, the 1st phase HCV RNA decline was steeper in patients with IL28B CC vs non‐CC genotype during SOC treatment. This did not translate into a higher frequency of RVR or SVR. Hence, the clinical relevance of pretreatment analysis of IL28B polymorphisms in genotype 2 and 3 infected patients can be questioned in patients with expected high SVR rate.     

HLA‐DQ polymorphisms with HBV infection: different outcomes upon infection and prognosis to lamivudine therapy

Two recent genome‐wide studies showed that the single‐nucleotide polymorphisms in the HLA‐DQ region (rs2856718 and rs9275572) were associated with chronic hepatitis B virus infection and chronic hepatitis C virus‐associated hepatocellular carcinoma in Japanese patients. We tested the effects of the two single‐nucleotide polymorphisms for all major HBV outcomes and lamivudine treatment in Han Chinese. A total of 1649 samples were enrolled, and peripheral blood samples were collected in this study. The single‐nucleotide polymorphisms in the HLA‐DQ region were genotyped using matrix‐assisted laser desorption/ionization time of flight mass spectrometry. Our study demonstrated the clear relevance of HLA‐DQ rs2856718 and rs9275572 with HBV susceptibility, natural clearance and HBV‐associated HCC. HLA‐DQ rs2856718G and rs9275572A were strongly associated with decreased risk of chronic HBV infection (odds ratio = 0.641; P = 2.64 × 10⁻⁴; odds ratio = 0.627, P = 7.22 × 10⁻⁵) and HBV natural clearance (odds ratio = 0.610; P = 4.80 × 10⁻⁴; odds ratio = 0.714, P = 0.013). Moreover, rs9275572A was also associated with development of cirrhosis and hepatocellular carcinoma (odds ratio = 0.632, P = 0.008). In addition, we showed for the first time to our knowledge that rs9275572 was a predictor for lamivudine therapy (viral response: odds ratio = 2.599, P = 4.43 × 10⁻⁴; biochemical response: odds ratio = 2.279, P = 4.23 × 10⁻⁴). Our study suggested that HLA‐DQ loci were associated with both HBV clearance and HBV‐related diseases and outcomes of lamivudine treatment in Han Chinese.     

HCV E1E2‐MF59 vaccine in chronic hepatitis C patients treated with PEG‐IFNα2a and Ribavirin: a randomized controlled trial

Hepatitis C virus (HCV) vaccines may be able to increase viral clearance in combination with antiviral therapy. We analysed viral dynamics and HCV‐specific immune response during retreatment for experienced patients in a phase Ib study with E1E2MF59 vaccine. Seventy‐eight genotype 1a/1b patients [relapsers (30), partial responders (16) and nonresponders (32) to interferon‐(IFN)/ribavirin‐(RBV)] were randomly assigned to vaccine (V:23), Peg‐IFNα2a‐180‐ug/qw and ribavirin 1000–1200‐mg/qd for 48 weeks (P/R:25), or their combination (P/R + V:30). Vaccine (100 μg/0.5 mL) was administered intramuscularly at week 0‐4‐8‐12‐24‐28‐32‐36. Neutralizing of binding (NOB) antibodies and lymphocyte proliferation assay (LPA) for E1E2‐specific‐CD4 + T cells were performed at week 0‐12‐16‐48. Viral kinetics were analysed up to week 16. The vaccine was safe, and a sustained virological response (SVR) was achieved in 4 P/R + V and 2 P/R patients. Higher SVR rates were observed in prior relapsers (P/R + V = 27.3%; P/R = 12.5%). Higher NOB titres and LPA indexes were found at week 12 and 16 in P/R + V as compared to P/R patients (P = 0.023 and 0.025, P = 0.019 and <0.001, respectively). Among the 22 patients with the strongest direct antiviral effects of IFN (ε ≥ 0.800), those treated with P/R + V (10) reached lower HCV‐RNA levels (P = 0.026) at week 16. HCV E1E2MF59 vaccine in combination with Peg‐IFNα2a + RBV was safe and elicited E1E2 neutralizing antibodies and specific CD4 + T cell proliferation. Upon early response to IFN, vaccinations were associated with an enhanced second phase viral load decline. These results prompt phase II trials in combination with new antiviral therapies.     

IL28B genetic variation and hepatitis C virus–specific CD4+ T‐cell responses in anti‐HCV‐positive blood donors

Summary. Epidemiological, viral and host factors are associated with the outcome of hepatitis C virus (HCV) infection, and strong host immune responses against HCV favour viral clearance. Recently, genome‐wide association studies have shown a strong correlation between single‐nucleotide polymorphisms (SNPs) near the interleukin‐28B (IL28B) gene and spontaneous or treatment‐induced HCV clearance. We have investigated whether protective IL28B genetic variants are associated with HCV‐specific T‐cell responses among Spanish blood donors. The rs12979860 IL28B haplotype was determined in 69 anti‐HCV‐positive blood donors (21 HCV RNA negative and 48 HCV RNA positive) and 30 seronegative donors. In all cases, HCV‐specific CD4⁺ T‐cell responses to HCV recombinant proteins (core, NS3 and NS3 helicase) were assessed by ex vivo interferon‐γ ELISpot assay. The rs12979860‐CC genotype was highly overrepresented in donors with spontaneous HCV clearance when compared to those with chronic infection (76.2%vs 29.2%, P < 0.001; odds ratio, 7.77; 95% confidence interval, 2.4–25.3, P < 0.001). HCV‐specific CD4⁺ T‐cell responses were detected in 16 (76.2%) spontaneous resolvers especially towards nonstructural proteins, but with no correlation with IL28B genotype. Chronic individuals had a significantly lower overall T‐cell response again irrespective of IL28B genotype. When spontaneous resolvers and chronic individuals were stratified according to their IL28B genotype, significantly stronger T‐cell responses were only observed among those with non‐CC haplotypes. Although the protective rs12979860 IL28B CC genotype is associated with spontaneous HCV clearance, stronger CD4⁺ T‐cell responses towards NS3 were only evident among those with non‐CC haplotypes.     

IL28RA polymorphism (rs10903035) is associated with insulin resistance in HIV/HCV‐coinfected patients

Hepatitis C virus (HCV) infection is associated with insulin resistance (IR), although mechanisms leading to IR in these patients are not completely understood. The aim of this study was to evaluate the association of interleukin 28B (IL28B) and interleukin 28 receptor alpha (IL28RA) polymorphisms with IR among human immunodeficiency virus (HIV)/HCV‐coinfected patients. We carried out a cross‐sectional study on 203 patients. IL28B (rs8099917) and IL28RA (rs10903035) polymorphisms were genotyped by GoldenGate^® assay. IR was defined as homeostatic model assessment (HOMA) values ≥3.00. Univariate and multivariate generalized linear models (GLM) were used to compare HOMA values and the percentage of patients with IR according to IL28B and IL28RA genotypes. In total, 32% (n = 65/203) of the patients had IR. IL28B rs8099917 TT was not significantly associated with HOMA values and IR. In contrast, rs10903035 AA was significantly associated with high HOMA values taking into account all patients (P = 0.024), as well as the subgroups of patients with significant fibrosis (P = 0.047) and infected with HCV genotype 3 (P = 0.024). Additionally, rs10903035 AA was significantly associated with IR (HOMA ≥3.00) in all patients (adjusted odds ratio (aOR) = 2.02; P = 0.034), in patients with significant fibrosis (aOR = 2.86; P = 0.039) and HCV genotype 3 patients (aOR = 4.89; P = 0.031). In conclusions, IL28RA polymorphism (rs10903035) seems to be implicated in the glucose homeostasis because AA genotype increases the likelihood of IR, but this association was different depending on hepatic fibrosis and HCV genotype.     

Type I IFNs promote the early IFN‐γ response and the IL‐10 response in Leishmania mexicana infection

The protozoan parasite Leishmania mexicana causes chronic cutaneous disease in humans and most mouse strains. We previously showed that STAT4‐deficient mice, but not IL‐12p40‐deficient mice, have more parasites and progressively growing lesions unlike those of wild‐type mice, the lesions and parasite burdens of which plateau by 10–12 weeks post‐infection. This demonstrates a STAT4‐dependent, IL‐12/IL‐23‐independent pathway of parasite control. Type I IFNs are important in viral and other infections and can activate STAT4. We found that IFN‐α/βR‐deficient mice have a nonpersistent, early IFN‐γ defect, and a persistent, early IL‐10 defect, without changes in serum IL‐12 or LN‐derived nitric oxide. We found less IL‐10 per cell in CD25⁺CD4⁺ T cells and possibly fewer IL‐10‐producing cells in the draining LN of IFN‐α/βR‐deficient vs. wild‐type mice. IFN‐α/βR‐deficient mice have chronic, nonprogressive disease, like wild‐type mice, suggesting that IL‐10 and IFN‐γ defects may balance each other. Our data indicate that although type I IFNs help promote early Th1 responses, they are not the missing activators of STAT4 responsible for partial control of L. mexicana. Also, the lack of lesion resolution in IFN‐α/βR‐deficient mice despite lower IL‐10 levels indicates that other pathways independent of T cell IL‐10 help prevent an IL‐12‐driven clearance of parasites.     

Relative expression analysis of IL‐5 and IL‐6 genes in tropical sheep breed Pelibuey infected with Haemonchus contortus

Haemonchus contortus is a parasitic nematode of Pelibuey sheep, a meat breed used in tropical regions. Due to anthelmintic problems, the identification of hosts resistant to H. contortus is another option of control. The aim of this study was to analyse the relative expression of IL‐5 and IL‐6 genes in Pelibuey sheep after H. contortus infection. Nineteen lambs infected with H. contortus and three more lambs without infection were studied. The haemonchosis was determined by the number of eggs per gram of faeces (epg) and by the estimation of the percentage of the packed cell volume (%pcv). Peripheral blood mononuclear cells (PBMCs) were obtained to extract RNA at 0, 1, 2, 7, 14, 21 and 28 days after infection to quantify the relative expression of IL‐5, IL‐6 and GAPDH by real‐time PCR. Five lambs were classified as low responders (lr) to haemonchosis with averages of 1519 ± 315·3 epg and 31·49 ± 5·13%pcv, and 14 lambs were identified as high responders (hr) with averages of 530 ± 132 epg and 34·88 ± 3·75%pcv. The expression ratio of IL‐5 was significantly different compared with control lambs at 2, 7 and 14 days post‐infection (PI), and IL‐6 was significantly different after 14 days. The highest level of relative expression for IL‐5 and IL‐6 genes was 9·9‐fold and 12‐fold after 2 and 14 days for hr hosts (P < 0·05) compared with control group, respectively. In conclusion, the Pelibuey breed in grazing areas exhibited different expression of IL‐5 and IL‐6 obtained from PBMCs against H. contortus, suggesting the importance of these cytokines in regulating the nematode infection.     

Expression and gene polymorphisms of interleukin 28B and hepatitis B virus infection in a Chinese Han population

Background: Recent genome‐wide association studies found that genetic polymorphisms near the IL28B gene is strongly associated with sustained viral response and spontaneous viral clearance in chronically infected hepatitis C patients. Aims: We aimed to evaluate the effects of IL28B variations on hepatitis B virus (HBV) infection in a Chinese Han population and to explore the association between IL28B polymorphisms and susceptibility to infection, viral clearance, disease progression, viral load and liver inflammation. Methods: We determined three IL28B single gene polymorphisms (rs12979860, rs12980275 and rs8099917) in 203 individuals with chronic HBV infection, 203 individuals with self‐limited HBV infection and 203 individuals negative for all HBV seromarkers. Interleukin (IL)28B serum levels were evaluated in all subjects. Additionally, peripheral blood mononuclear cells from 42 chronically HBV‐infected individuals were subjected to whole‐genome expression studies. Results: The association among genotype, allele and haplotype frequencies of IL28B with alanine aminotransferase levels and HBV DNA was established. However, no significant differences were observed in genotype or allele frequencies among chronically HBV‐infected, self‐limited and healthy subjects. The serum IL28B level was lower in patients with chronic HBV infection than in the self‐limited HBV‐infected or healthy subjects. The serum IL28B level was correlated with the subject's genotype. Gene expression micro‐array analysis showed enhanced IL28B expression in patients with low HBV viral load. Conclusions: Variability at the IL28B locus is associated with HBV viral load and hepatic inflammation. Genetic variation of IL28B may prevent HBV progression by reducing viral load and liver inflammation, providing a valuable gene therapy tool.     

ITPA genetic variants influence efficacy of PEG‐IFN/RBV therapy in older patients infected with HCV genotype 1 and favourable IL28B type

Inosine triphosphatase (ITPA) genetic variants are strongly associated with ribavirin (RBV)‐induced anaemia during pegylated interferon (PEG‐IFN) plus RBV therapy. However, the treatment efficacy of ITPA genetic variants has not been fully explored. We enrolled 309 individuals infected with hepatitis C virus genotype 1, who were treated with PEG‐IFN plus RBV for 48 weeks. The ITPA SNP: rs1127354 and IL28B SNP: rs8099917 were genotyped. We examined the risk factors for severe anaemia up to week 12 after the start of treatment and treatment efficacy. The incidence of severe anaemia, ≥3 g/dL reduction or <10 g/dL of haemoglobin (Hb) up to week 12, was more frequent in patients with CC at rs1127354 [65% (145/224), 33% (73/224)] than in those with CA/AA [25% (21/85), 6% (8/85)] (P < 0.0001). ITPA genotype, pretreatment Hb level and age were independent predictive factors for severe anaemia: Hb < 10 g/dL. In IL28B favourable type, the sustained virologic response rate was higher in ≥60‐year‐old patients with CA/AA than in those with CC [71% (22/31) vs 40% (26/65), P = 0.005], although there was no significant difference in treatment efficacy according to ITPA genetic variants in the <60‐year‐old patients. The proportion of patients administered ≥80% of the dosage of RBV was significantly higher in the patients with CA/AA than in those with CC (P = 0.025), resulting in a lower relapse rate. In conclusion, ITPA genetic variants were associated with severe RBV‐induced anaemia and could influence the efficacy of PEG‐IFN plus RBV treatment among elderly patients with IL28B favourable type.     

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.     

Flt3 ligand treatment modulates parasitemia during infection with rodent malaria parasites via MyD88‐ and IFN‐γ‐dependent mechanisms

We previously showed that treatment of mice with the Flt3 ligand (Flt3L) prevents development of lethal experimental cerebral malaria and inhibits parasitemia during Plasmodium berghei ANKA (PbA) infection. In this study, we investigated the mechanisms underlying the reduction of parasitemia in Flt3L‐treated mice. Studies using gene knockout mice and antibody treatment indicated that the anti‐parasitemia effect of Flt3L was mediated by innate immune system and was dependent on MyD88, IFN‐γ, IL‐12 and natural killer (NK) cells. The number of NK cells and their ability to produce IFN‐γ was enhanced in Flt3L‐treated mice. Phagocytic activity of splenocytes was increased in Flt3L‐treated mice after PbA infection when compared with that in untreated mice, and this activity was mainly mediated by the accumulation of F4/80^midCD11b⁺ cells in the spleen. In both MyD88^?/? and IFN‐γ^?/? mice, the proportion of F4/80^midCD11b⁺ cells was not increased in the spleen of Flt3L‐treated mice after infection. These correlations suggest that NK cells produce IFN‐γ in Flt3L‐treated mice, and accumulation of F4/80^midCD11b⁺ cells in the spleen is promoted by an IFN‐γ ‐dependent manner, culminating in the inhibition of parasitemia. These findings imply that Flt3L promotes effective innate immunity against malaria infection mediated by interplay among varieties of innate immune cells.