Shared and Distinct Functions of Type I and Type III Interferons.

Type I interferons (IFNs) (IFN-α, IFN-ß) and type III IFNs (IFN-λ) share many properties, including induction by viral infection, activation of shared signaling pathways, and transcriptional programs. However, recent discoveries have revealed context-specific functional differences. Here, we provide a comprehensive review of type I and type III IFN activities, highlighting shared and distinct features from molecular mechanisms through physiological responses. Beyond discussing canonical antiviral functions, we consider the adaptive immune priming, anti-tumor, and autoimmune functions of IFNs. We discuss a model wherein type III IFNs serve as a front-line defense that controls infection at epithelial barriers while minimizing damaging inflammatory responses, reserving the more potent type I IFN response for when local responses are insufficient. In this context, we discuss current therapeutic applications targeting these cytokine pathways and highlight gaps in understanding of the biology of type I and type III IFNs in health and disease.

MicroRNA-218-5p-Ddx41 axis restrains microglia-mediated neuroinflammation through downregulating type I interferon response in a mouse model of Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Microglia-mediated neuroinflammation has been largely considered one of main factors to the PD pathology. MicroRNA-218-5p (miR-218-5p) is a microRNA that plays a role in neurodevelopment and function, while its potential function in PD and neuroinflammation remains unclear. METHODS: We explore the involvement of miR-218-5p in the PD in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model. The miR-218-5p agomir used for overexpression was delivered into the substantia nigra (SN) by bilateral stereotaxic infusions. The loss of dopaminergic (DA) neurons and microglial inflammation in the SN was determined using Western blotting and immunofluorescence. Motor function was assessed using the rotarod test. RNA sequencing (RNA-seq) was performed to explore the pathways regulated by miR-218-5p. The target genes of miR-218-5p were predicted using TargetScan and confirmed using dual luciferase reporter assays. The effects of miR-218-5p on microglial inflammation and related pathways were verified in murine microglia-like BV2 cells. To stimulate BV2 cells, SH-SY5Y cells were treated with 1-methyl-4-phenylpyridinium (MPP+) and the conditioned media (CM) were collected. RESULTS: MiR-218-5p expression was reduced in both the SN of MPTP-induced mice and MPP+-treated BV2 cells. MiR-218-5p overexpression significantly alleviated MPTP-induced microglial inflammation, loss of DA neurons, and motor dysfunction. RNA sequence and gene set enrichment analysis showed that type I interferon (IFN-I) pathways were upregulated in MPTP-induced mice, while this upregulation was reversed by miR-218-5p overexpression. A luciferase reporter assay verified that Ddx41 was a target gene of miR-218-5p. In vitro, miR-218-5p overexpression or Ddx41 knockdown inhibited the IFN-I response and expression of inflammatory cytokines in BV2 cells stimulated with MPP+-CM. CONCLUSIONS: MiR-218-5p suppresses microglia-mediated neuroinflammation and preserves DA neurons via Ddx41/IFN-I. Hence, miR-218-5p-Ddx41 is a promising therapeutic target for PD.

Tumor necrosis factor ALPHA Inhibitor Associated Köhlmeier-Degos Disease as a Novel Iatrogenic Paradigm That Underscores Excessive Type I Interferon in Its Pathogenesis.

ABSTRACT: Malignant atrophic papulosis/Köhlmeier-Degos disease was first described in 1941 by Köhlmeier in an anecdotal case report that described a young man who presented with extensive multiple intestinal perforations and a papular skin rash. Köhlmeier-Degos disease represents a unique vasculopathy targeting both the microvasculature and the arterial system. One of its most characteristic features is reflected by the discrete multifocal depressed porcelain lesions involving the skin and gastrointestinal tract. The pathological findings are striking and can be broadly categorized into those that are vascular in nature versus extravascular matrix production in the context of extensive extravascular hyaluronic acid and collagen deposition. A dynamic evolutionary morphology is observed not only clinically but also histologically. The microvascular alterations are particularly evident in the skin and are characterized by endothelial cell necrosis with subsequent endothelial cell detachment accompanied by intraluminal fibrin deposition, defining a thrombogenic microangiopathy that in later stage lesions is typically pauci-inflammatory. The arterial lesions are very distinctive and include significant neointimal proliferation with vascular luminal occlusion by amorphous plugs of collagen intimately admixed with platelets. Pathogenetically enhanced type I interferon signaling and endothelial cell injury mediated by the membranolytic attack complex (ie, C5b-9) are key in the evolution of the thrombotic microvascular and obliterative fibrosing arteriopathic changes. We describe a case of Köhlmeier-Degos disease that developed in the setting of tumor necrosis factor (TNF)-alpha inhibitor therapy with the drug golimumab. The clinical features, light microscopic findings, and a pathophysiologic paradigm based on the critical role of TNF-alpha in controlling the type I interferon response are discussed.

Type I interferon-related kidney disorders.

Type I interferon (IFN-I) mediates tissue damage in a wide range of kidney disorders, directly affecting the biology and function of several renal cell types including podocytes, mesangial, endothelial, and parietal epithelial cells. Enhanced IFN-I signaling is observed in the context of viral infections, autoimmunity (e.g., systemic lupus erythematosus), and type 1 interferonopathies, rare monogenic disorders characterized by constitutive activation of the IFN-I pathway. All these IFN-I-related disorders can cause renal dysfunction and share pathogenic and histopathological features. Collapsing glomerulopathy, a histopathological lesion characterized by podocyte loss, collapse of the vascular tuft, and parietal epithelial cell proliferation, is commonly associated with viral infections, has been described in type 1 interferonopathies such as Aicardi-Goutières syndrome and stimulator of IFN genes-associated vasculopathy with onset in infancy, and can also be induced by recombinant IFN therapy. In all these conditions, podocytes and parietal epithelial cells seem to be the primary target of IFN-I-mediated damage. Additionally, immune-mediated glomerular injury is common to viral infections, systemic lupus erythematosus, and type 1 interferonopathies such as coatomer subunit-α syndrome (COPA) and DNASE1L3 deficiency, diseases in which IFN-I apparently promotes immune-mediated kidney injury. Finally, kidney pathology primarily characterized by vascular lesions (e.g., thrombotic microangiopathy and vasculitis) is a hallmark of type 1 interferonopathy adenosine deaminase 2 deficiency as well as of systemic lupus erythematosus, viral infections, and IFN therapy. Defining the nosology, pathogenic mechanisms, and histopathological patterns of IFN-I-related kidney disorders has diagnostic and therapeutic implications, especially considering the likely near-term availability of novel drugs targeting the IFN-I pathway.

Anifrolumab efficacy and safety by type I interferon gene signature and clinical subgroups in patients with SLE: post hoc analysis of pooled data from two phase III trials.

OBJECTIVES: To characterise the efficacy and safety of anifrolumab in patients with systemic lupus erythematosus (SLE) according to interferon gene signature (IFNGS), demographic and clinical subgroups. METHODS: We performed post hoc analyses of pooled data from the 52-week phase III TULIP-1/TULIP-2 placebo-controlled trials of intravenous anifrolumab in moderate-to-severe SLE. Outcomes were assessed in predefined subgroups: IFNGS (high/low), age, sex, body mass index, race, geographic region, age of onset, glucocorticoid use, disease activity and serological markers. RESULTS: In pooled data, patients received anifrolumab 300 mg (360/726) or placebo (366/726); 82.6% were IFNGS-high. IFNGS-high patients had greater baseline disease activity and were more likely to have abnormal serological markers versus IFNGS-low patients. In the total population, a greater proportion of patients treated with anifrolumab versus placebo achieved British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) response at week 52 (difference 16.6%; nominal p<0.001). BICLA response treatment differences with anifrolumab versus placebo were comparable to the total population across most predefined subgroups, including subgroups for baseline glucocorticoid dosage (<10/≥10 mg/day prednisone/equivalent) and for clinical disease activity (SLE Disease Activity Index 2000 score <10/≥10). Subgroups with larger treatment differences included IFNGS-high patients (18.2%), patients with abnormal baseline serological markers (23.1%) and Asian patients (29.2%). The safety profile of anifrolumab was similar across subgroups. CONCLUSIONS: Overall, this study supports the consistent efficacy and safety of anifrolumab across a range of patients with moderate-to-severe SLE. In a few subgroups, small sample sizes limited conclusions from being drawn regarding the treatment benefit with anifrolumab. TRIAL REGISTRATION NUMBER: NCT02446912, NCT02446899.

Type I interferon signature in Sjögren's syndrome: pathophysiological and clinical implications.

Type I interferons (IFN) have long been recognised as mediators of innate immune defense mechanisms against viral threats. Robust evidence over the last 15 years revealed their significant role in the pathogenesis of systemic autoimmune diseases, including systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS). Despite the progress, methods of detection, initial triggers, biological functions and clinical associations in the setting of autoimmunity remain to be fully clarified. As therapeutic options for SS are currently limited, neutralising specific targets of the type I IFN pathway seems a promising option. In this review we summarise the current evidence regarding the role of type I IFN in SS.

Type I interferon causes thrombotic microangiopathy by a dose-dependent toxic effect on the microvasculature.

Many drugs have been reported to cause thrombotic microangiopathy (TMA), yet evidence supporting a direct association is often weak. In particular, TMA has been reported in association with recombinant type I interferon (IFN) therapies, with recent concern regarding the use of IFN in multiple sclerosis patients. However, a causal association has yet to be demonstrated. Here, we adopt a combined clinical and experimental approach to provide evidence of such an association between type I IFN and TMA. We show that the clinical phenotype of cases referred to a national center is uniformly consistent with a direct dose-dependent drug-induced TMA. We then show that dose-dependent microvascular disease is seen in a transgenic mouse model of IFN toxicity. This includes specific microvascular pathological changes seen in patient biopsies and is dependent on transcriptional activation of the IFN response through the type I interferon α/ß receptor (IFNAR). Together our clinical and experimental findings provide evidence of a causal link between type I IFN and TMA. As such, recombinant type I IFN therapies should be stopped at the earliest stage in patients who develop this complication, with implications for risk mitigation.

Janus-like effects of type I interferon in autoimmune diseases.

In multiple sclerosis, type I interferon (IFN) is considered immune-modulatory, and recombinant forms of IFN-ß are the most prescribed treatment for this disease. This is in contrast to most other autoimmune disorders, because type I IFN contributes to the pathologies. Even within the relapsing-remitting multiple sclerosis (RRMS) population, 30-50% of MS patients are non-responsive to this treatment, and it consistently worsens neuromyelitis optica, a disease similar to RRMS. In this article, we discuss the recent advances in the field of autoimmunity and introduce the theory explain how type I IFNs can be pro-inflammatory in disease that is predominantly driven by a Th17 response and are therapeutic when disease is predominantly Th1.

Psychometric evaluation of the hepatitis C virus patient-reported outcomes (HCV-PRO) instrument: validity, responsiveness, and identification of the minimally important difference in a phase 2 clinical trial.

PURPOSE: To describe the psychometric properties and identify the minimally important difference (MID) of the hepatitis C virus patient-reported outcomes (HCV-PRO) instrument. Chronic HCV infection and associated treatments negatively affect PROs of function and well-being. METHODS: In a phase 2 trial, HCV-infected patients received direct-acting antivirals (DAAs) for 12 weeks with peg-interferon/ribavirin (peg-IFN/RBV) for 48 weeks, or placebo plus peg-IFN/RBV. The HCV-PRO total score, SF-36 PCS and MCS scores, EQ-5D-3L, and EQ VAS were measured at baseline, week 8, end of DAA treatment (EODT), end of peg-IFN/RBV treatment (EOT), and posttreatment week 24 (SVR24). Convergent validity of the HCV-PRO was assessed by Pearson's correlation coefficients. Discriminant validity was assessed by analyzing mean HCV-PRO total scores by EQ-5D anxiety/depression and pain/discomfort domain scores (none vs. some) and presence/absence of depression or fatigue adverse events. MID was identified through effect size (ES) and receiver-operating characteristic (ROC) curve analyses (HCV-PRO response vs. SF-36 PCS/MCS and EQ VAS MID thresholds). RESULTS: In 74 patients (22 % female; 81 % White; 51 % ≥50 years), correlations (0.64-0.96) between HCV-PRO total scores, SF-36 PCS/MCS scores, and EQ VAS scores at all time points supported convergent validity. HCV-PRO total scores were reduced to 10-30 points in patients impaired by depression, pain, or fatigue symptoms. Impact of peg-IFN/RBV regimen on HCV-PRO ES increased over time (EODT -0.76; EOT -0.93). ES and ROC curve analyses indicated an MID of -10 points. CONCLUSION: The HCV-PRO was valid and responsive in the population studied. An MID of -10 points represented a threshold of clinical significance for the HCV-PRO.

Recombinant interferon-α may retard progression of early primary myelofibrosis: a preliminary report.

The limited effects of current treatments of primary myelofibrosis (PM) led us to prospectively evaluate recombinant interferon-α (rIFNα) in "early" PM patients with residual hematopoiesis and only grade 1 or 2 myelofibrosis. Seventeen patients meeting World Health Organization PM diagnostic criteria received either rIFNα-2b 500 000 to 3 million units 3 times weekly, or pegylated rIFNα-2a 45 or 90 µg weekly. International Working Group for Myelofibrosis Research and Treatment criteria for prognosis and response were used. Eleven patients were women and 6 were men. Their median age at diagnosis was 57 years. Eleven patients were low risk and 6 were intermediate-1 risk. Two achieved complete remission, 7 partial, 1 clinical improvement, 4 stable disease, and 3 had progressive disease. Thus, more than 80% derived clinical benefit or stability. Improvement in marrow morphology occurred in 4. Toxicity was acceptable. These results, with documented marrow reversion because of interferon treatment, warrant expanded evaluation.

Suicide risk in hepatitis C and during interferon-alpha therapy: a review and clinical update.

Chronic hepatitis C (CHC) affects over 170 million individuals worldwide and is a growing public health concern. Despite the availability of CHC treatment, specifically interferon-α and ribavirin, treatment of CHC is limited by concerns about psychiatric side effects including risks of suicide. Although depression has been the focus of neuropsychiatric complications from interferon-alpha (IFNα), emerging evidence has contributed to our understanding of IFNα-induced suicidal ideation and attempts. Using Pubmed, we performed a literature review of all English articles published between 1989 and April 1, 2010 on suicide in untreated and IFNα-treated patients with CHC. References in all identified review articles were scanned and included in our review. A total of 17 articles were identified. Studies have suggested that the first 12 weeks of IFNα therapy are the high-risk period. Moreover, the emergence of suicidal ideation can be linked to neuropsychiatric abnormalities, specifically serotonin depletion. Pretreatment with antidepressant treatment should be reserved for high-risk groups, as this may reduce the risk of depression and thus decrease the suicide risk indirectly. Although there is a paucity of literature on suicide and suicide risk during IFNα therapy for CHC, recent studies on IFNα-induced depression have provided some potential insights into suicide in this patient population. Further research examining the effects of pharmacological and nonpharmacological interventions on suicide risk during IFNα treatment is needed.

Dyspnoea in patients with chronic hepatitis C treated with pegylated interferon and ribavirin.

BACKGROUND: Adverse events attributed to the treatment of chronic hepatitis C patients with pegylated interferon (PEG-IFN) and ribavirin have been widely discussed. Lung disorders have been described, but the respiratory function of these patients during treatment has not been well studied. The aim of this study was to investigate the incidence of dyspnoea and possible changes in lung function associated with the use of PEG-IFN and ribavirin. METHODS: We evaluated clinical data and spirometry in 31 patients with chronic hepatitis C infections prior to treatment, in the 2(nd) week of treatment and in the 12(th) week of treatment. RESULTS: During the follow-up period, 19 patients (61.3%) had dyspnoea. Decreased haemoglobin levels were observed during the study, but there was no significant association with dyspnoea. However, patients with a body mass index (BMI) greater than 25 had a higher incidence of dyspnoea. No significant difference was detected between the values of forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), or forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio measured during the investigation. However, a significant decrease in FEV1 and FEV1/FVC ratio was observed in patients with later stages of liver fibrosis. CONCLUSIONS: Dyspnoea is a frequently occurring respiratory symptom during chronic hepatitis C treatment, and it is not associated with changes in spirometric parameters in the first 12 weeks of treatment. However, changes in FEV1 and FEV1/FVC can be observed in patients with advanced liver disease in the first 12 weeks of treatment with PEG-IFN and ribavirin.

Altered expression of genes controlling metabolism characterizes the tissue response to immune injury in lupus.

To compare lupus pathogenesis in disparate tissues, we analyzed gene expression profiles of human discoid lupus erythematosus (DLE) and lupus nephritis (LN). We found common increases in myeloid cell-defining gene sets and decreases in genes controlling glucose and lipid metabolism in lupus-affected skin and kidney. Regression models in DLE indicated increased glycolysis was correlated with keratinocyte, endothelial, and inflammatory cell transcripts, and decreased tricarboxylic (TCA) cycle genes were correlated with the keratinocyte signature. In LN, regression models demonstrated decreased glycolysis and TCA cycle genes were correlated with increased endothelial or decreased kidney cell transcripts, respectively. Less severe glomerular LN exhibited similar alterations in metabolism and tissue cell transcripts before monocyte/myeloid cell infiltration in some patients. Additionally, changes to mitochondrial and peroxisomal transcripts were associated with specific cells rather than global signal changes. Examination of murine LN gene expression demonstrated metabolic changes were not driven by acute exposure to type I interferon and could be restored after immunosuppression. Finally, expression of HAVCR1, a tubule damage marker, was negatively correlated with the TCA cycle signature in LN models. These results indicate that altered metabolic dysfunction is a common, reversible change in lupus-affected tissues and appears to reflect damage downstream of immunologic processes.

Si-Ni-San ameliorates chronic colitis by modulating type I interferons-mediated inflammation.

BACKGROUND: Ulcerative colitis (UC) is a chronic relapsing inflammatory disease that markedly elevates the risk of colon cancers and results in disability. The disrupted immune homeostasis has been recognized as a predominant player in the pathogenesis of UC. However, the overall remission rate of current therapies based on immunoregulation is still unsatisfactory. Si-Ni-San (SNS) has been found effective in relieving UC through thousands of years of clinical practice, yet the specific mechanisms of the protective effect of SNS were not fully elucidated. PURPOSE: We aim to investigate the therapeutic effects of SNS against the development of chronic colitis and the underlying mechanisms. METHODS: We established a DSS-induced chronic experimental colitis mouse model to evaluate the effect of SNS. RNA-sequencing, bioinformatic analysis, and in vitro studies were performed to investigate the underlying mechanisms. RESULTS: Our data demonstrated that SNS significantly ameliorated chronic experimental colitis via inhibiting the expression of genes associated with inflammatory responses. Interestingly, SNS significantly suppressed DSS-induced type I interferon (IFN) responses instead of directly downregulating the production of pro-inflammatory cytokines, such as Il-6. In vitro study further found that SNS selectively inhibited STING and RIG-I pathway-induced type I IFN responses by modulating TBK1- and IRF3-dependent signaling transduction. SNS also suppressed the expression of IFN-stimulated genes by directly inhibiting STAT1 and STAT2 activation. CONCLUSION: Our study not only provides novel insights into the pathogenic role of type I IFN responses in colitis but also suggested that SNS or bioactive compounds derived from SNS may serve as novel therapeutic strategies for the treatment of UC via interfering type I IFN-mediated inflammation.

Functional polymorphisms in the interleukin-6 and serotonin transporter genes, and depression and fatigue induced by interferon-alpha and ribavirin treatment.

Depression and fatigue are frequent side effects of interferon-alpha (IFN-alpha) treatment, and there is compelling evidence that the inflammatory response system (including interleukin-6, IL-6) and the serotonergic system is important in the pathophysiology of such symptoms. Functional polymorphisms in the promoter region of the IL-6 gene (rs1800795) and serotonin transporter gene (5-HTTLPR) have been identified as regulating these systems. The present study aimed to determine if these polymorphisms were associated with the development of depression and fatigue during IFN-alpha and ribavirin treatment. Ninety-eight Caucasian patients receiving pegylated IFN-alpha and ribavirin treatment for chronic hepatitis C virus at King's College Hospital, London, and Emory University Hospital, Atlanta, participated in this prospective cohort study. Symptoms of depression and fatigue were measured before treatment and at weeks 4, 8, 12 and 24 during treatment. The 'low IL-6' synthesizing genotype (CC) was associated with significantly fewer symptoms of depression (effect size = 0.7 at week 24; F = 9.4, d.f. = 436, P = 0.002). The 'high transcription' serotonin transporter (5-HTT) genotype (LL) was also associated with significantly fewer symptoms of depression, but with a much smaller effect (effect size = 0.2 at week 24; F = 4.5, d.f. = 436, P = 0.03). Neither polymorphisms were associated with symptoms of fatigue (IL-6: F = 1.2, d.f. = 430, P = 0.2; 5-HTT: F = 0.5, d.f. = 430, P = 0.5). The smaller effects of the 5-HTT polymorphism on depression may be explained by an interaction between the genes (F = 5.0, d.f. = 434, P = 0.02): the 'protective' effect of the 5-HTTLPR polymorphism was evident only in the presence of the 'low IL-6' genotype (F = 5.4, d.f. = 64, P = 0.02), not in the presence of the 'high IL-6' genotype (F = 2.2, d.f. = 369, P = 0.1). The association between the IL-6 polymorphism and reduced risk of depressive symptoms confirms the role of the inflammatory response system in the pathophysiology of IFN-alpha-induced depression; in contrast, the effect of the 5-HTT gene was small and perhaps dependent on the status of the inflammatory response.

Aggregated recombinant human interferon Beta induces antibodies but no memory in immune-tolerant transgenic mice.

PURPOSE: To study the influence of protein aggregation on the immunogenicity of recombinant human interferon beta (rhIFNbeta) in wild-type mice and transgenic, immune-tolerant mice, and to evaluate the induction of immunological memory. METHODS: RhIFNbeta-1b and three rhIFNbeta-1a preparations with different aggregate levels were injected intraperitoneally in mice 15x during 3 weeks, and the mice were rechallenged with rhIFNbeta-1a. The formation of binding (BABs) and neutralizing antibodies (NABs) was monitored. RESULTS: Bulk rhIFNbeta-1a contained large, mainly non-covalent aggregates and stressed rhIFNbeta-1a mainly covalent, homogeneous (ca. 100 nm) aggregates. Reformulated rhIFNbeta-1a was essentially aggregate-free. All products induced BABs and NABs in wild-type mice. Immunogenicity in the transgenic mice was product dependent. RhIFNbeta-1b showed the highest and reformulated rhIFNbeta-1a the lowest immunogenicity. In contrast with wild-type mice, transgenic mice did not show NABs, nor did they respond to the rechallenge. CONCLUSIONS: The immunogenicity of the products in transgenic mice, unlike in wild-type mice, varied. In the transgenic mice, neither NABs nor immunological memory developed. The immunogenicity of rhIFNbeta in a model reflecting the human immune system depends on the presence and the characteristics of aggregates.

Comparative efficacy and overall safety of different doses of consensus interferon for treatment of chronic HCV infection: a systematic review and meta-analysis.

BACKGROUND: About one-half of patients with hepatitis C genotype 1 and one-third with genotype 2/3 have treatment failure with peginterferon alpha and ribavirin. Consensus interferon (CIFN) is an option for retreatment of these patients. OBJECTIVE: To summarize comparative safety and efficacy of different regimens of CIFN for the treatment of patients with chronic hepatitis C infection. DATA SOURCE: Medline, Scopus, ISI, and Cochran Central Register of Clinical Trials were used. STUDY ELIGIBILITY CRITERIA: Randomized clinical trials (RCTs) were eligible for inclusion in the study. PARTICIPANTS: HIV and HBV seronegative patients with positive HCV-RNA during the 6 months before the start of the study were eligible for inclusion. INTERVENTIONS: Different regimens of CIFN were studied. STUDY APPRAISAL AND SYNTHESIS METHODS: Studies were appraised based on methods of random sequence generation, allocation concealment, and blinding. The random effects model of DerSimonian and Laird was employed to run the meta-analysis. The end-point was sustained virological response (SVR). RESULTS: Data of 10 RCTs including 1,600 subjects were extracted. High daily induction dose regimen of CIFN did not yield a higher rate of SVR than low daily induction dose treatment regimen, RR = 0.83 (95% CI 0.58-1.17). A dose of 9 µg thrice weekly (tiw) was associated with a significantly higher rate of SVR compared with 3 µg [RR = 3.14 (95% CI 1.68-5.58)][Symbol: see text]. Withdrawal rate was similar [RR = 1.28 (95% CI 0.65-2.50)] but dose modification was higher in 9 µg [RR = 3.22 (95% CI 1.08-9.60)]. A dose of 18/15 µg tiw was not more effective than 9 µg over a similar treatment duration [RR = 1.02 (95% CI 0. 87-1.19)]. LIMITATIONS: Limitations include inadequate reporting of methodological information and side effects, lack of publication bias assessment due to the small number of studies in each analysis. CONCLUSIONS: High dose daily induction therapy with CIFN is not superior to low dose therapy in terms of SVR. It seems that 9 µg tiw is the optimal treatment dose of CIFN for treatment of HCV infection. Optimal duration and safety profile of CIFN therapy have yet been elucidated.

Evaluation of safety, efficacy, tolerability, and treatment-related outcomes of type I interferons for human coronaviruses (HCoVs) infection in clinical practice: An updated critical systematic review and meta-analysis.

BACKGROUND: There is no vaccine or specific antiviral treatment for HCoVs infection. The use of type I interferons for coronavirus is still under great debate in clinical practice. MATERIALS AND METHODS: A literature search of all relevant studies published on PubMed, Cochrane library, Web of Science database, Science Direct, Wanfang Data, and China National Knowledge Infrastructure (CNKI) until February 2020 was performed. RESULTS: Of the 1081 identified articles, only 15 studies were included in the final analysis. Comorbidities and delay in diagnosis were significantly associated with case mortality. Type I interferons seem to improve respiratory distress, relieve lung abnormalities, present better saturation, reduce needs for supplemental oxygen support. Type I interferons seem to be well tolerated, and don't increase life threating adverse effects. Data on IFNs in HCoVs are limited, heterogenous and mainly observational. CONCLUSIONS: Current data do not allow making regarding robust commendations for the use of IFNs in HCoVs in general or in specific subtype. But we still recommend type I interferons serving as first-line antivirals in HCoVs infections within local protocols, and interferons may be adopted to the treatments of the SARS-CoV-2 as well. Well-designed large-scale prospective randomized control trials are greatly needed to provide more robust evidence on this topic.

Antiviral Activity of Type I, II, and III Interferons Counterbalances ACE2 Inducibility and Restricts SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), is a recently emerged respiratory coronavirus that has infected >23 million people worldwide with >800,000 deaths. Few COVID-19 therapeutics are available, and the basis for severe infections is poorly understood. Here, we investigated properties of type I (ß), II (γ), and III (λ1) interferons (IFNs), potent immune cytokines that are normally produced during infection and that upregulate IFN-stimulated gene (ISG) effectors to limit virus replication. IFNs are already in clinical trials to treat COVID-19. However, recent studies highlight the potential for IFNs to enhance expression of host angiotensin-converting enzyme 2 (ACE2), suggesting that IFN therapy or natural coinfections could exacerbate COVID-19 by upregulating this critical virus entry receptor. Using a cell line model, we found that beta interferon (IFN-ß) strongly upregulated expression of canonical antiviral ISGs, as well as ACE2 at the mRNA and cell surface protein levels. Strikingly, IFN-λ1 upregulated antiviral ISGs, but ACE2 mRNA was only marginally elevated and did not lead to detectably increased ACE2 protein at the cell surface. IFN-γ induced the weakest ISG response but clearly enhanced surface expression of ACE2. Importantly, all IFN types inhibited SARS-CoV-2 replication in a dose-dependent manner, and IFN-ß and IFN-λ1 exhibited potent antiviral activity in primary human bronchial epithelial cells. Our data imply that type-specific mechanisms or kinetics shape IFN-enhanced ACE2 transcript and cell surface levels but that the antiviral action of IFNs against SARS-CoV-2 counterbalances any proviral effects of ACE2 induction. These insights should aid in evaluating the benefits of specific IFNs, particularly IFN-λ, as repurposed therapeutics.IMPORTANCE Repurposing existing, clinically approved, antiviral drugs as COVID-19 therapeutics is a rapid way to help combat the SARS-CoV-2 pandemic. Interferons (IFNs) usually form part of the body's natural innate immune defenses against viruses, and they have been used with partial success to treat previous new viral threats, such as HIV, hepatitis C virus, and Ebola virus. Nevertheless, IFNs can have undesirable side effects, and recent reports indicate that IFNs upregulate the expression of host ACE2 (a critical entry receptor for SARS-CoV-2), raising the possibility that IFN treatments could exacerbate COVID-19. Here, we studied the antiviral- and ACE2-inducing properties of different IFN types in both a human lung cell line model and primary human bronchial epithelial cells. We observed differences between IFNs with respect to their induction of antiviral genes and abilities to enhance the cell surface expression of ACE2. Nevertheless, all the IFNs limited SARS-CoV-2 replication, suggesting that their antiviral actions can counterbalance increased ACE2.