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1.
Liver Int ; 36(12): 1774-1782, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27224844

RESUMO

BACKGROUND & AIMS: Hepatitis C virus (HCV) is bound to plasma lipoproteins and circulates as an infectious lipoviral particle (LVP). Experimental evidence indicates that LVPs have decreased susceptibility to antibody-mediated neutralisation and higher infectivity. This study tested the hypothesis that LVPs are required to establish persistent infection, and conversely, low levels of LVP in recent HCV infection increase the probability of spontaneous HCV clearance. METHODS: LVP in non-fasting plasma was measured using the concentration of HCV RNA bound to large >100 nm sized lipoproteins after ex vivo addition of a lipid emulsion, that represented the maximum concentration of LVP (maxi-LVP). This method correlated with LVP in fasting plasma measured using iodixanol density gradient ultracentrifugation. Maxi-LVP was measured in a cohort of 180 HCV participants with recent HCV infection and detectable HCV RNA from the Australian Trial in Acute Hepatitis C (ATAHC) and Hepatitis C Incidence and Transmission Study in prison (HITS-p) cohorts. RESULTS: Spontaneous clearance occurred in 15% (27 of 180) of individuals. In adjusted analyses, low plasma maxi-LVP level was independently associated with spontaneous HCV clearance (≤827 IU/ml; adjusted odds ratio 3.98, 95% CI: 1.02, 15.51, P = 0.047), after adjusting for interferon lambda-3 rs8099917 genotype, estimated duration of HCV infection and total HCV RNA level. CONCLUSIONS: Maxi-LVP is a biomarker for the maximum concentration of LVP in non-fasting samples. Low maxi-LVP level is an independent predictor of spontaneous clearance of acute HCV.


Assuntos
Hepacivirus/fisiologia , Hepatite C Crônica/virologia , Lipoproteínas/sangue , Vírion/fisiologia , Adulto , Austrália , Biomarcadores/metabolismo , Feminino , Genótipo , Hepatite C Crônica/genética , Humanos , Interferons , Interleucinas/genética , Modelos Logísticos , Masculino , RNA Viral/sangue , Carga Viral , Adulto Jovem
2.
J Hepatol ; 62(4): 763-70, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25463543

RESUMO

BACKGROUND & AIMS: Hepatitis C virus (HCV) associates with lipoproteins to form "lipoviral particles" (LVPs) that can facilitate viral entry into hepatocytes. Initial attachment occurs via heparan sulphate proteoglycans and low-density lipoprotein receptor (LDLR); CD81 then mediates a post-attachment event. Proprotein convertase subtilisin kexin type 9 (PCSK9) enhances the degradation of the LDLR and modulates liver CD81 levels. We measured LVP and PCSK9 in patients chronically infected with HCV genotype (G)3. PCSK9 concentrations were also measured in HCV-G1 to indirectly examine the role of LDLR in LVP clearance. METHODS: HCV RNA, LVP (d<1.07g/ml) and non-LVP (d>1.07g/ml) fractions, were quantified in patients with HCV-G3 (n=39) by real time RT-PCR and LVP ratios (LVPr; LVP/(LVP+non-LVP)) were calculated. Insulin resistance (IR) was assessed using the homeostasis model assessment of IR (HOMA-IR). Plasma PCSK9 concentrations were measured by ELISA in HCV-G3 and HCV-G1 (n=51). RESULTS: In HCV-G3 LVP load correlated inversely with HDL-C (r=-0.421; p=0.008), and apoE (r=-0.428; p=0.013). The LVPr varied more than 35-fold (median 0.286; range 0.027 to 0.969); PCSK9 was the strongest negative predictor of LVPr (R(2)=16.2%; p=0.012). HOMA-IR was not associated with LVP load or LVPr. PCSK9 concentrations were significantly lower in HCV-G3 compared to HCV-G1 (p<0.001). PCSK9 did not correlate with LDL-C in HCV-G3 or G1. CONCLUSIONS: The inverse correlation of LVP with apoE in HCV-G3, compared to the reverse in HCV-G1 suggests HCV genotype-specific differences in apoE mediated viral entry. Lower PCSK9 and LDL concentrations imply upregulated LDLR activity in HCV-G3.


Assuntos
Apolipoproteínas E/metabolismo , LDL-Colesterol/metabolismo , Hepacivirus/genética , Hepatite C Crônica , Pró-Proteína Convertases/metabolismo , Serina Endopeptidases/metabolismo , Vírion/metabolismo , Adulto , Feminino , Genótipo , Hepatite C Crônica/metabolismo , Hepatite C Crônica/virologia , Hepatócitos/metabolismo , Humanos , Lipoproteínas LDL/metabolismo , Masculino , Pessoa de Meia-Idade , Pró-Proteína Convertase 9 , RNA Viral/análise , Receptores de LDL/metabolismo , Estatística como Assunto
3.
Liver Int ; 34(5): 737-47, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24118830

RESUMO

BACKGROUND & AIMS: Hepatitis C virus (HCV) utilises cholesterol and lipoprotein metabolism for replication and infectivity. Statins and omega-3 (n-3) polyunsaturated fatty acids (PUFA) have been shown to have antiviral properties in vitro. This open label pilot study evaluated the efficacy of fluvastatin (Lescol(®) 40-80 mg) and n-3 PUFA (Omacor(®) 1 g and 2-4 g) on HCV-RNA and lipoviral particles (LVP) in difficult to treat prior non-responders. METHODS: Patients (n = 60) were randomly allocated in a factorial design to: no active drug; low-dose n-3 PUFA; high-dose n-3 PUFA; fluvastatin; low-dose n-3 PUFA + fluvastatin; or high-dose n-3 PUFA + fluvastatin. 50/60 completed study drugs for 12 weeks and followed up to week 24. Comparison was made between fluvastatin (n = 24) vs no fluvastatin (n = 26) and n-3 PUFA high-dose (n = 17) vs low-dose (n = 17) vs none (n = 16). The primary outcomes were change in total HCV-RNA, LVP and ALT at week 12 compared with baseline. Secondary outcome was change in interferon-gamma-inducible protein-10 (IP10) as a measure of interferon activation. RESULTS: 35% had compensated cirrhosis and 45% were prior null responders. There was no significant change in total HCV RNA, LVP, non-LVP or LVP ratio in patients receiving fluvastatin or n-3 PUFAs. ALT was not significantly different in those treated with fluvastatin or n-3 PUFAs. 12 weeks of low-dose n-3 PUFA decreased median IP10 concentration by -39 pg/ml (-111, 7.0 pg/ml Q1-Q3). CONCLUSIONS: Fluvastatin and n-3 PUFAs have no effect on plasma HCV-RNA or LVP. The effect of low-dose n-3 PUFA on IP10 warrants further prospective evaluation as a supplemental therapy to enhance interferon sensitivity.


Assuntos
Antivirais/uso terapêutico , Ácidos Graxos Monoinsaturados/uso terapêutico , Ácidos Graxos Ômega-3/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Indóis/uso terapêutico , Adulto , Alanina Transaminase/sangue , Quimiocina CXCL10/sangue , Quimioterapia Combinada , Ácidos Graxos Monoinsaturados/farmacologia , Ácidos Graxos Ômega-3/farmacologia , Feminino , Fluvastatina , Hepatite C Crônica/sangue , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Indóis/farmacologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Carga Viral/efeitos dos fármacos
4.
Clin Infect Dis ; 56(7): 951-60, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23223601

RESUMO

BACKGROUND: Through migration, diversity of chronic hepatitis B virus (HBV) infection has changed, affecting disease burden and control. We describe clinical and viral characteristics of chronic HBV in the United Kingdom. METHODS: A total of 698 individuals with chronic HBV infection were recruited from referral liver centers. Demographic, clinical, and laboratory data were collected. RESULTS: Sixty-one percent of patients were male, 80% were not born in the United Kingdom, and the largest ethnicity was East/Southeast Asian (36%). Twenty-two percent were hepatitis B e antigen (HBeAg) seropositive; 20.4% (59/289) had cirrhosis and 10 (1.7%) had hepatocellular carcinoma. Genotype D was most common (31%) followed by A, C, B, and E (20%, 20%, 19%, and 9%, respectively). Genotype was significantly associated with country of birth, length of time in the United Kingdom, HBeAg status, and precore and basal core promoter mutations. One-third were on treatment, with men independently more likely to be treated. Only 18% of those on treatment were on recommended first-line therapies, and 30% were on lamivudine monotherapy. Among treated individuals, 27% had antiviral drug resistance. Testing rates for human immunodeficiency virus, hepatitis C virus, and delta coinfections were low. CONCLUSIONS: We demonstrated diversity of chronic HBV infections in UK patients, suggesting that optimal management requires awareness of the variable patterns of chronic HBV in countries of origin. We also found less-than-optimal clinical management practices, possible gender-based treatment bias, and the need to improve testing for coinfections.


Assuntos
Carcinoma Hepatocelular/epidemiologia , Vírus da Hepatite B/classificação , Vírus da Hepatite B/genética , Hepatite B Crônica/epidemiologia , Hepatite B Crônica/virologia , Cirrose Hepática/epidemiologia , Adulto , Estudos Transversais , Feminino , Genótipo , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/complicações , Hepatite B Crônica/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reino Unido/epidemiologia
5.
J Hepatol ; 57(1): 32-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22414761

RESUMO

BACKGROUND & AIMS: Hepatitis C virus (HCV) interacts with apolipoproteins B (apoB) and E (apoE) to form infectious lipoviral particles (LVP). Response to peginterferon is influenced by interferon-stimulated genes (ISGs) and IL28B genotype. LDL cholesterol (LDL-C) also predicts interferon response, therefore we hypothesised that LVP may also be associated with interferon sensitivity. METHODS: LVP (HCV RNA density ≤1.07 g/ml) and 'non-LVP' (d >1.07 g/ml) were measured in 72 fasted HCV-G1 patients by iodixanol density gradient ultracentrifugation and the LVP ratio (LVP/LVP+non-LVP) was calculated. Fasting lipid profiles and apolipoproteins B and E were measured. Interferon-gamma-inducible protein 10 kDa (IP10), a marker of ISGs, was measured by ELISA. RESULTS: Complete early virological response (EVR) was associated with lower apoE (23.9±7.7 vs. 36.1±15.3 mg/L, p=0.013), higher LDL-C (p=0.039) and lower LVP ratios (p=0.022) compared to null responders. In multivariate linear regression analysis, apoE was independently associated with LVP (R(2) 19.5%, p=0.003) and LVP ratio (p=0.042), and negatively with LDL-C (p<0.001). IP10 was significantly associated with ApoB (p=0.001) and liver stiffness (p=0.032). IL28B rs12979860 CC was associated with complete EVR (p=0.044), low apoE (CC 28±11 vs. CT/TT 35±13 mg/L, p=0.048) and higher non-LVP (p=0.008). Logistic regression analysis indicated that patients with high LVP ratios were less likely to have EVR (odds ratio 0.01, p=0.018). CONCLUSIONS: In HCV-G1, interferon sensitivity is characterised by low LVP ratios and low apoE levels in addition to higher LDL-C and IL28B rs12979860 CC. Null-response is associated with increased LVP ratio. The association of apoE and LVP with peginterferon treatment response suggests that lipid modulation is a potential target to modify interferon sensitivity.


Assuntos
Antivirais/farmacologia , Apolipoproteínas E/sangue , Hepacivirus/metabolismo , Hepatite C , Vírion/metabolismo , Adulto , Apolipoproteínas B/sangue , Biomarcadores/sangue , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Farmacorresistência Viral/fisiologia , Feminino , Genótipo , Hepacivirus/genética , Hepatite C/tratamento farmacológico , Hepatite C/metabolismo , Hepatite C/virologia , Humanos , Interferon-alfa/genética , Interferon-alfa/metabolismo , Interferon gama/genética , Interferon gama/metabolismo , Interferons , Interleucinas/genética , Interleucinas/metabolismo , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Carga Viral/fisiologia , Vírion/genética
6.
Gut ; 60(5): 680-7, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20940286

RESUMO

BACKGROUND: The density of hepatitis C virus (HCV) in plasma is heterogeneous but the factors which influence this are poorly understood. Evidence from animal models and cell culture suggest that low-density apolipoprotein B (apoB)-associated HCV lipoviral particles (LVP) are more infectious than high-density HCV. Objective To measure LVP in patients with chronic hepatitis C genotype 1 (CHC-G1) and examine metabolic determinants of LVP load. Patients 51 patients with CHC-G1 infection. METHODS: Fasting lipid profiles and homeostasis model assessment of insulin resistance (HOMA-IR) were determined in 51 patients with CHC-G1. LVP and non-LVP viral load were measured by real-time PCR of plasma at density <1.07 g/ml and >1.07 g/ml, respectively, following iodixanol density gradient ultracentrifugation. The LVP ratio was calculated using the formula: LVP/(LVP + non-LVP). RESULTS: The mean LVP ratio was 0.241 but varied 25-fold (from 0.029 to 0.74). Univariate analysis showed that the LVP ratio correlated with HOMA-IR (p=0.004) and the triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio (p = 0.004), but not with apoB. In multivariate analysis, HOMA-IR was the main determinant of LVP load (log10IU/ml) (R²=16.6%; p = 0.037) but the TG/HDL-C ratio was the strongest predictor of the LVP ratio (R² = 24.4%; p = 0.019). Higher LVP ratios were associated with non-response to antiviral therapy (p = 0.037) and with greater liver stiffness (p = 0.001). CONCLUSION: IR and associated dyslipidaemia are the major determinants of low-density apoB-associated LVP in fasting plasma. This provides a possible mechanism to explain why IR is associated with more rapidly progressive liver disease and poorer treatment outcomes.


Assuntos
Hepacivirus/isolamento & purificação , Hepatite C Crônica/genética , Resistência à Insulina/fisiologia , Vírion/isolamento & purificação , Adulto , Antivirais/uso terapêutico , Apolipoproteínas B/sangue , Centrifugação com Gradiente de Concentração/métodos , HDL-Colesterol/sangue , Estudos de Coortes , Feminino , Genótipo , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/fisiopatologia , Hepatite C Crônica/virologia , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Resultado do Tratamento , Triglicerídeos/sangue , Carga Viral , Vírion/genética
7.
Sci Rep ; 12(1): 5562, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35365728

RESUMO

Lipids play essential roles in the hepatitis C virus (HCV) life cycle and patients with chronic HCV infection display disordered lipid metabolism which resolves following successful anti-viral therapy. It has been proposed that HCV genotype 3 (HCV-G3) infection is an independent risk factor for hepatocellular carcinoma and evidence suggests lipogenic proteins are involved in hepatocarcinogenesis. We aimed to characterise variation in host lipid metabolism between participants chronically infected with HCV genotype 1 (HCV-G1) and HCV-G3 to identify likely genotype-specific differences in lipid metabolism. We combined several lipidomic approaches: analysis was performed between participants infected with HCV-G1 and HCV-G3, both in the fasting and non-fasting states, and after sustained virological response (SVR) to treatment. Sera were obtained from 112 fasting patients (25% with cirrhosis). Serum lipids were measured using standard enzymatic methods. Lathosterol and desmosterol were measured by gas-chromatography mass spectrometry (MS). For further metabolic insight on lipid metabolism, ultra-performance liquid chromatography MS was performed on all samples. A subgroup of 13 participants had whole body fat distribution determined using in vivo magnetic resonance imaging and spectroscopy. A second cohort of (non-fasting) sera were obtained from HCV Research UK for comparative analyses: 150 treatment naïve patients and 100 non-viraemic patients post-SVR. HCV-G3 patients had significantly decreased serum apoB, non-HDL cholesterol concentrations, and more hepatic steatosis than those with HCV-G1. HCV-G3 patients also had significantly decreased serum levels of lathosterol, without significant reductions in desmosterol. Lipidomic analysis showed lipid species associated with reverse cholesterol transport pathway in HCV-G3. We demonstrated that compared to HCV-G1, HCV-G3 infection is characterised by low LDL cholesterol levels, with preferential suppression of cholesterol synthesis via lathosterol, associated with increasing hepatic steatosis. The genotype-specific lipid disturbances may shed light on genotypic variations in liver disease progression and promotion of hepatocellular cancer in HCV-G3.


Assuntos
Hepacivirus , Hepatite C , Colesterol , Genótipo , Hepacivirus/genética , Humanos , Metabolismo dos Lipídeos/genética
8.
PLoS Med ; 8(9): e1001092, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21931540

RESUMO

BACKGROUND: To date, drug response genes have not proved as useful in clinical practice as was anticipated at the start of the genomic era. An exception is in the treatment of chronic hepatitis C virus (HCV) genotype 1 infection with pegylated interferon-alpha and ribavirin (PegIFN/R). Viral clearance is achieved in 40%-50% of patients. Interleukin 28B (IL28B) genotype predicts treatment-induced and spontaneous clearance. To improve the predictive value of this genotype, we studied the combined effect of variants of IL28B with human leukocyte antigen C (HLA-C), and its ligands the killer immunoglobulin-like receptors (KIR), which have previously been implicated in HCV viral control. METHODS AND FINDINGS: We genotyped chronic hepatitis C (CHC) genotype 1 patients with PegIFN/R treatment-induced clearance (n = 417) and treatment failure (n = 493), and 234 individuals with spontaneous clearance, for HLA-C C1 versus C2, presence of inhibitory and activating KIR genes, and two IL28B SNPs, rs8099917 and rs12979860. All individuals were Europeans or of European descent. IL28B SNP rs8099917 "G" was associated with absence of treatment-induced clearance (odds ratio [OR] 2.19, p = 1.27×10(-8), 1.67-2.88) and absence of spontaneous clearance (OR 3.83, p = 1.71×10(-14), 2.67-5.48) of HCV, as was rs12979860, with slightly lower ORs. The HLA-C C2C2 genotype was also over-represented in patients who failed treatment (OR 1.52, p = 0.024, 1.05-2.20), but was not associated with spontaneous clearance. Prediction of treatment failure improved from 66% with IL28B to 80% using both genes in this cohort (OR 3.78, p = 8.83×10(-6), 2.03-7.04). There was evidence that KIR2DL3 and KIR2DS2 carriage also altered HCV treatment response in combination with HLA-C and IL28B. CONCLUSIONS: Genotyping for IL28B, HLA-C, and KIR genes improves prediction of HCV treatment response. These findings support a role for natural killer (NK) cell activation in PegIFN/R treatment-induced clearance, partially mediated by IL28B.


Assuntos
Antígenos HLA-C/genética , Hepacivirus/patogenicidade , Hepatite C Crônica/terapia , Interleucinas/genética , Adulto , Alelos , Antivirais/uso terapêutico , Estudos de Casos e Controles , Estudos de Coortes , Estudos Transversais , Quimioterapia Combinada , Feminino , Genótipo , Hepacivirus/imunologia , Hepatite C Crônica/genética , Hepatite C Crônica/imunologia , Hepatite C Crônica/virologia , Humanos , Interferon-alfa/uso terapêutico , Interferons , Células Matadoras Naturais/imunologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Farmacogenética/métodos , Polimorfismo de Nucleotídeo Único , Valor Preditivo dos Testes , RNA Viral/análise , Receptores KIR/genética , Receptores KIR2DL3/genética , Ribavirina/uso terapêutico , Resultado do Tratamento , Carga Viral , População Branca
9.
J Hepatol ; 55(6): 1428-40, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21718665

RESUMO

Atherosclerosis has been described as a liver disease of the heart [1]. The liver is the central regulatory organ of lipid pathways but since dyslipidaemias are major contributors to cardiovascular disease and type 2 diabetes rather than liver disease, research in this area has not been a major focus for hepatologists. Virus-host interaction is a continuous co-evolutionary process [2] involving the host immune system and viral escape mechanisms [3]. One of the strategies HCV has adopted to escape immune clearance and establish persistent infection is to make use of hepatic lipid pathways. This review aims to: • update the hepatologist on lipid metabolism • review the evidence that HCV exploits hepatic lipid pathways to its advantage • discuss approaches to targeting host lipid pathways as adjunctive therapy.


Assuntos
Hepatite C/metabolismo , Hepatite C/terapia , Metabolismo dos Lipídeos , Fígado/metabolismo , Apolipoproteínas A/metabolismo , Apolipoproteínas B/metabolismo , Apolipoproteínas E/metabolismo , Quilomícrons/metabolismo , Hepacivirus/metabolismo , Hepacivirus/patogenicidade , Hepatite C/virologia , Humanos , Hipolipemiantes/uso terapêutico , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipoproteínas VLDL/metabolismo , Redes e Vias Metabólicas , Modelos Biológicos
10.
Gastroenterology ; 139(5): 1774-83, 1783.e1-6, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20682323

RESUMO

BACKGROUND & AIMS: The physical association of hepatitis C virus (HCV) particles with lipoproteins in plasma results in distribution of HCV in a broad range of buoyant densities. This association is thought to increase virion infectivity by mediating cell entry via lipoprotein receptors. We sought to determine if factors that affect triglyceride-rich lipoprotein (TRL) metabolism alter the density and dynamics of HCV particles in the plasma of patients with chronic HCV infection. METHODS: Fasting patients (n = 10) consumed a high-fat milkshake; plasma was collected and fractionated by density gradients. HCV- RNA was measured in the very-low-density fraction (VLDF, d < 1.025 g/mL) before and at 7 serial time points postprandially. RESULTS: The amount of HCV RNA in the VLDF (HCV(VLDF)) increased a mean of 26-fold, peaking 180 minutes after the meal (P < .01). Quantification of HCV RNA throughout the density gradient fractions revealed that HCV(VLDF) rapidly disappeared, rather than migrating into the adjacent density fraction. Immuno-affinity separation of the VLDF, using antibodies that recognize apolipoprotein B-100 and not apolipoprotein B-48, showed that HCV(VLDF) is composed of chylomicron- and VLDL-associated HCV particles; peaking 120 and 180 minutes after the meal, respectively. Plasma from fasting HCV-infected patients mixed with uninfected plasma increased the quantity of HCV(VLDF), compared with that mixed with phosphate-buffered saline, showing extracellular assembly of HCV(VLDF). CONCLUSIONS: Dietary triglyceride alters the density and dynamics of HCV in plasma. The rapid clearance rate of HCV(VLDF) indicates that association with TRL is important for HCV infectivity. HCV particles, such as exchangeable apolipoproteins, appear to reassociate with TRLs in the vascular compartment.


Assuntos
Hepacivirus/química , Hepatite C Crônica/sangue , Lipoproteínas VLDL/análise , Período Pós-Prandial/fisiologia , Viremia/sangue , Vírion/metabolismo , Adulto , Progressão da Doença , Feminino , Hepacivirus/genética , Hepatite C Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Carga Viral , Viremia/virologia
11.
Vaccines (Basel) ; 9(2)2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540927

RESUMO

The impactful discovery and subsequent characterisation of hepatitis C virus (HCV), an RNA virus of the flavivirus family, led to the awarding of the 2020 Nobel Prize in Physiology or Medicine to Harvey J. Alter, Michael Houghton and Charles M. Rice [...].

12.
Eur J Rheumatol ; 7(1): 37-40, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31922479

RESUMO

Polymyalgia rheumatica (PMR) is the most common inflammatory rheumatological condition affecting individuals aged >50 years. There have been rare reports of PMR and other vasculitides developing within 3 months of influenza vaccination. Influenza is a major public health issue associated with seasonal increased mortality and intensified health care service use. Annual vaccination is the most effective intervention to prevent influenza, especially in elderly individuals. We report a severe "flare" of PMR in a 70-year-old patient after receiving the adjuvanted trivalent influenza vaccine, as recommended by the Joint Committee on Vaccination and Immunisations for this age group in the UK National Health Service in 2018-2019. The adverse event (AE) could be interpreted as the newly described autoimmune/inflammatory syndrome induced by adjuvants (ASIA syndrome) as both PMR and ASIA display hyperactive immune responses. Caution is warranted in the use of vaccine adjuvants in patients with PMR with pre-existing imbalance of B and T cell homeostasis. Rare AEs are important to individuals, and personalized medicine means we should move away from "one size fits all" for vaccines, as well as for therapeutics.

13.
J Alzheimers Dis ; 75(1): 1-14, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32250293

RESUMO

Clinical specialization is not only a force for progress, but it has also led to the fragmentation of medical knowledge. The focus of research in the field of Alzheimer's disease (AD) is neurobiology, while hepatologists focus on liver diseases and lipid specialists on atherosclerosis. This article on AD focuses on the role of the liver and lipid homeostasis in the development of AD. Amyloid-ß (Aß) deposits accumulate as plaques in the brain of an AD patient long before cognitive decline is evident. Aß generation is a normal physiological process; the steady-state level of Aß in the brain is determined by balance between Aß production and its clearance. We present evidence suggesting that the liver is the origin of brain Aß deposits and that it is involved in peripheral clearance of circulating Aß in the blood. Hence the liver could be targeted to decrease Aß production or increase peripheral clearance.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Encéfalo/metabolismo , Fígado/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/patologia , Humanos , Metabolismo dos Lipídeos/fisiologia , Fígado/patologia , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia
14.
J Diabetes ; 12(9): 649-658, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32394639

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic is caused by a novel betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), similar to SARS-CoV and Middle East respiratory syndrome (MERS-CoV), which cause acute respiratory distress syndrome and case fatalities. COVID-19 disease severity is worse in older obese patients with comorbidities such as diabetes, hypertension, cardiovascular disease, and chronic lung disease. Cell binding and entry of betacoronaviruses is via their surface spike glycoprotein; SARS-CoV binds to the metalloprotease angiotensin-converting enzyme 2 (ACE2), MERS-CoV utilizes dipeptidyl peptidase 4 (DPP4), and recent modeling of the structure of SARS-CoV-2 spike glycoprotein predicts that it can interact with human DPP4 in addition to ACE2. DPP4 is a ubiquitous membrane-bound aminopeptidase that circulates in plasma; it is multifunctional with roles in nutrition, metabolism, and immune and endocrine systems. DPP4 activity differentially regulates glucose homeostasis and inflammation via its enzymatic activity and nonenzymatic immunomodulatory effects. The importance of DPP4 for the medical community has been highlighted by the approval of DPP4 inhibitors, or gliptins, for the treatment of type 2 diabetes mellitus. This review discusses the dysregulation of DPP4 in COVID-19 comorbid conditions; DPP4 activity is higher in older individuals and increased plasma DPP4 is a predictor of the onset of metabolic syndrome. DPP4 upregulation may be a determinant of COVID-19 disease severity, which creates interest regarding the use of gliptins in management of COVID-19. Also, knowledge of the chemistry and biology of DPP4 could be utilized to develop novel therapies to block viral entry of some betacoronaviruses, potentially including SARS-CoV-2.


Assuntos
Infecções por Coronavirus/complicações , Infecções por Coronavirus/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Pneumonia Viral/complicações , Pneumonia Viral/tratamento farmacológico , COVID-19 , Comorbidade , Dipeptidil Peptidase 4 , Humanos , Pandemias
15.
J Virol ; 82(24): 12020-9, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18829747

RESUMO

Hepatitis C virus (HCV) infection is dependent on at least three coreceptors: CD81, scavenger receptor BI (SR-BI), and claudin-1. The mechanism of how these molecules coordinate HCV entry is unknown. In this study we demonstrate that a cell culture-adapted JFH-1 mutant, with an amino acid change in E2 at position 451 (G451R), has a reduced dependency on SR-BI. This altered receptor dependency is accompanied by an increased sensitivity to neutralization by soluble CD81 and enhanced binding of recombinant E2 to cell surface-expressed and soluble CD81. Fractionation of HCV by density gradient centrifugation allows the analysis of particle-lipoprotein associations. The cell culture-adapted mutation alters the relationship between particle density and infectivity, with the peak infectivity occurring at higher density than the parental virus. No association was observed between particle density and SR-BI or CD81 coreceptor dependence. JFH-1 G451R is highly sensitive to neutralization by gp-specific antibodies, suggesting increased epitope exposure at the virion surface. Finally, an association was observed between JFH-1 particle density and sensitivity to neutralizing antibodies (NAbs), suggesting that lipoprotein association reduces the sensitivity of particles to NAbs. In summary, mutation of E2 at position 451 alters the relationship between particle density and infectivity, disrupts coreceptor dependence, and increases virion sensitivity to receptor mimics and NAbs. Our data suggest that a balanced interplay between HCV particles, lipoprotein components, and viral receptors allows the evasion of host immune responses.


Assuntos
Anticorpos/imunologia , Anticorpos/farmacologia , Especificidade de Anticorpos/imunologia , Antígenos CD/metabolismo , Receptores Depuradores Classe B/metabolismo , Proteínas do Envelope Viral/metabolismo , Animais , Antígenos CD/genética , Linhagem Celular , Cricetinae , Humanos , Mutação/genética , Ligação Proteica , Solubilidade , Tetraspanina 28 , Proteínas do Envelope Viral/genética , Vírion/efeitos dos fármacos , Vírion/imunologia , Vírion/metabolismo
16.
Hepatol Int ; 12(1): 17-25, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29423541

RESUMO

BACKGROUND/PURPOSE: One to three per cent of the world's population has hepatitis C virus (HCV) infection, which is not only a major cause of liver disease and cancer but also associated with an increased risk of atherosclerosis, despite an ostensibly favourable lipid profile. Autoantibodies are frequent in HCV infection and emerging evidence shows that autoantibodies could be valuable for cardiovascular disease (CVD) risk stratification. This study investigated a novel independent biomarker of CVD, autoantibodies to apolipoprotein A-1 (anti-apoA-1 IgG) and lipids in patients with chronic HCV before, during and after direct-acting anti-viral (DAA) therapy. METHODS: Eighty-nine blinded serum samples from 27 patients with advanced chronic HCV were assayed for lipids and anti-apoA-1 IgG by ELISA. RESULTS: Pre-treatment HCV viral load correlated with high-density lipoprotein cholesterol (HDL-C, r = 0.417; p = 0.042) and negatively with apolipoprotein (apo)B (r = - 0.497; p = 0.013) and markers of CVD risk, the apoB/apoA-1 ratio (r = - 0.490; p = 0.015) and triglyceride level (TG)/HDL-C ratio (r = - 0.450; p = 0.031). Fourteen (52%) of 27 patients had detectable anti-apoA-1 IgG autoantibodies pre-treatment; only two became undetectable with virological cure. Autoantibody-positive sera had lower apoA-1 (p = 0.012), HDL-C (p = 0.009) and total cholesterol (p = 0.006) levels. CONCLUSIONS: This is the first report of the presence of an emerging biomarker for atherosclerosis, anti-apoA-1 IgG, in some patients with HCV infection. It may be induced by apoA-1 on the surface of HCV lipoviral particles. The autoantibodies inversely correlate with apoA-1 and HDL levels and may render HDL dysfunctional. Whether these hypothesis-generating findings have clinical implications in HCV patients requires further study.


Assuntos
Apolipoproteína A-I/imunologia , Autoanticorpos/sangue , Biomarcadores/sangue , Doença da Artéria Coronariana/sangue , Hepatite C/imunologia , Idoso , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Doença da Artéria Coronariana/imunologia , Feminino , Hepacivirus/imunologia , Hepatite C/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Carga Viral
17.
Clin Gastroenterol Hepatol ; 5(6): 755-60, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17482523

RESUMO

BACKGROUND & AIMS: Twin and family studies suggest that there is a significant heritable component to primary biliary cirrhosis (PBC). Selected cytotoxic T-lymphocyte-associated antigen-4 (CTLA4) gene polymorphisms have been proposed as nonspecific determinants of disease risk in a variety of autoimmune diseases, including PBC. However, there has been considerable debate over the validity of these associations and the precise location of the disease-promoting polymorphism. METHODS: We investigated 6 single-nucleotide polymorphisms in the CTLA4 gene in a total of 327 PBC patients and 391 healthy controls: 247 patients and 292 controls from the United Kingdom and a further 80 patients and 99 controls from northern Italy. RESULTS: The previously reported association with CTLA4 A+49G was not replicated in the Italian series, and there were no significant differences in the distribution of any of the 6 polymorphisms comparing allele, genotype, or haplotype distribution in patients vs healthy controls in the UK series. Furthermore, there were no significant associations with the clinical variables of histologic stage, portal hypertension, or Mayo score. However, when PBC-40 Fatigue Domain scores were considered, a number of significant trends were noted, but none were significant after correction for multiple testing. Thus, fatigue scores were higher in those with the CTLA4 -319 T allele (P < .05, p corrected not significant) and in those with the CTLA4 +49 AA genotype (P < .05, pc not significant). CONCLUSIONS: Contrary to previous reports the CTLA4 gene is not a major risk factor for PBC, nor is it a major determinant of disease progression.


Assuntos
Antígenos CD/genética , Antígenos de Diferenciação/genética , Cirrose Hepática Biliar/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Antígeno CTLA-4 , Progressão da Doença , Feminino , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Técnicas de Amplificação de Ácido Nucleico , Estudos Soroepidemiológicos , Reino Unido/epidemiologia , População Branca/genética
20.
Frontline Gastroenterol ; 5(2): 111-117, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24683447

RESUMO

OBJECTIVE: Vertical transmission of the hepatitis B virus (HBV) is the commonest mode of infection and can be prevented with immunoprophylaxis of the infant and antiviral therapy in the mother. Our aim was to review a cohort of subjects with HBV in pregnancy to determine the prevalence of active disease or high HBV-DNA levels that required treatment to prevent transmission, and to review the management of mothers and infants. METHODS: A retrospective case-note review was conducted of all the HBV-infected pregnant women and their infants who attended the Newcastle obstetric services from 2007 to 2011. RESULTS: There were 113 pregnancies in 81 women (median age 28 years; 15% hepatitis B e antigen (HBeAg) positive) during 2007-11. 71% of mothers were first diagnosed with HBV during pregnancy. The mothers were born in 28 different countries. 69% of mothers had an HBV-DNA level less than 2000 IU/mL and 13% had HBV-DNA levels greater than 1.0×107 IU/mL so would be eligible for antiviral therapy to prevent transmission to the infant. 9% had active eAg-positive HBV and 3% had active eAg-negative HBV requiring treatment. All infants born to HBeAg-positive mothers received hepatitis B immunoglobulin (HBIG) appropriately and 76% of infants received a full HBV vaccination course. One infant born to an HBeAg-negative mother was hepatitis B surface antigen positive 1 year post-delivery. CONCLUSIONS: One in six women had active HBV requiring treatment or high HBV-DNA levels that would benefit from antiviral treatment to reduce the transmission risk. HBIG was administered appropriately but completion of the vaccination course was suboptimal.

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