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Purpose Calculation of extracellular volume fraction (ECV) currently receives increasing interest as a potential biomarker for non-invasive assessment of liver fibrosis. ECV calculation requires hematocrit (Hct) sampling, which might be difficult to obtain in a high-throughput radiology department. The aim of this study was to generate synthetic ECV for hepatic applications without the need for Hct sampling. Methods In this prospective study participants underwent liver MRI. T1 mapping was performed before and after contrast administration. Blood Hct was obtained prior to MRI. We hypothesized that the relationship between Hct and longitudinal relaxation rate of blood (R1 = 1/T1blood) could be calibrated and used to generate the equation for synthetic Htc and ECV calculation. Conventional and synthetic ECV were calculated. Pearson correlation, linear regression and Bland–Altman method were used for statistical analysis. Results 180 consecutive patients were divided into derivation (n = 90) and validation (n = 90) cohorts. In the derivation cohort, native R1blood and Hct showed a linear relationship (HctMOLLI = 98.04 × (1/T1blood) − 33.17, R2 = 0.75, P r = 0.99, 0.97 and 0.99, respectively, P Conclusion Synthetic ECV seems to offer an alternative method for non-invasive quantification of the hepatic ECV. It may potentially overcome an important barrier to clinical implementation of ECV and thus, enable broader use of hepatic ECV in routine clinical practice.

HIV-1 broadly neutralizing antibodies (bNAbs) are able to suppress viremia and prevent infection. Their induction by vaccination is therefore a major goal. However, in contrast to antibodies that neutralize other pathogens, HIV-1-specific bNAbs frequently carry uncommon molecular characteristics that might prevent their induction. Here, we performed unbiased sequence analyses of B cell receptor repertoires from 57 healthy and 46 chronically HIV-1- or HCV-infected individuals and learned probabilistic models to predict the likelihood of bNAb development. We formally show that lower probabilities for bNAbs are predictive of higher HIV-1 neutralization activity. Moreover, ranking of bNAbs by their probabilities allowed to identify highly potent antibodies with superior generation probabilities as preferential targets for vaccination approaches. Importantly, we found equal bNAb probabilities across infected and healthy donors. This implies that chronic infection is not a prerequisite for the generation of bNAbs, fostering the hope that HIV-1 vaccines can induce bNAb development in healthy individuals.Significance StatementWhile HIV-1 broadly neutralizing antibodies (bNAbs) can develop in chronically HIV-1-infected individuals, they could not yet be elicited by active vaccination. Here, we computationally demonstrate that HIV-1 bNAbs carry distinct sequence features making them unlikely outcomes of the antibody evolution. However, our approach allowed us to identify bNAbs with higher probabilities of being generated. These candidates can now serve as the most promising targets to be induced by vaccination. Moreover, we show that chronic infection has no influence on the probabilities of finding typical bNAb sequence features in the memory B cell compartment. Both findings are critical to design effective vaccination strategies.

ObjectiveNeutralising antibodies are key effectors of infection-induced and vaccine-induced immunity. Quantification of antibodies’ breadth and potency is critical for understanding the mechanisms of protection and for prioritisation of vaccines. Here, we used a unique collection of human specimens and HCV strains to develop HCV reference viruses for quantification of neutralising antibodies, and to investigate viral functional diversity.DesignWe profiled neutralisation potency of polyclonal immunoglobulins from 104 patients infected with HCV genotype (GT) 1–6 across 13 HCV strains representing five viral GTs. Using metric multidimensional scaling, we plotted HCV neutralisation onto neutralisation maps. We employed K-means clustering to guide virus clustering and selecting representative strains.ResultsViruses differed greatly in neutralisation sensitivity, with J6 (GT2a) being most resistant and SA13 (GT5a) being most sensitive. They mapped to six distinct neutralisation clusters, in part composed of viruses from different GTs. There was no correlation between viral neutralisation and genetic distance, indicating functional neutralisation clustering differs from sequence-based clustering. Calibrating reference viruses representing these clusters against purified antibodies from 496 patients infected by GT1 to GT6 viruses readily identified individuals with extraordinary potent and broadly neutralising antibodies. It revealed comparable antibody cross-neutralisation and diversity between specimens from diverse viral GTs, confirming well-balanced reporting of HCV cross-neutralisation across highly diverse human samples.ConclusionRepresentative isolates from six neutralisation clusters broadly reconstruct the functional HCV neutralisation space. They enable high resolution profiling of HCV neutralisation and they may reflect viral functional and antigenic properties important to consider in HCV vaccine design.

Abstract HLA-B*57 affects the course of HIV infection. Under antiretroviral therapy, its effects cannot be explained by outstandingly efficient T cell responses alone but may also involve cells of innate immunity. Studying in vitro stimulation with Pam3CSK4, E. coli LPS-B5 and CpG-ODN-2216, we observed greater induction of IL-6/IL-1beta double-positive CD14+CD16++ monocytes as well as IFN-gamma-positive cytotoxic CD56highCD16neg NK cells in HLA-B*57- versus HLA-B*44-positive HIV patients, while TNF-alpha induction remained unchanged. Differences were not seen in the other monocyte and NK cell subsets or in HLA-matched healthy controls. Our findings show that, in virally suppressed HIV infection, HLA-B*57 is associated with enhanced responsiveness of inflammatory innate immune cells to TLR ligands, possibly contributing to increased vulnerability in sepsis. Key messages • HLA-B*57 is a host factor affecting clinical outcomes of HIV infection. • HLA-B*57 modifies inflammatory subsets of NK cells and monocytes in HIV infection. • In HLA-B*57-positive HIV patients TLR agonists induce enhanced IL-6/IL-1beta in monocytes. • NK cells from HLA-B*57 HIV patients release more IFN-gamma upon TLR costimulation. • HLA-B*57 is linked to enhanced inflammatory responsiveness to TLR ligands.

Purpose Autoimmune hepatitis (AIH) is an immune-mediated chronic liver disease that leads to severe fibrosis and cirrhosis. The aim of this study was to determine the diagnostic value of T1 and T2 mapping as well as extracellular volume fraction (ECV) for non-invasive assessment of liver fibrosis in AIH patients. Methods In this prospective study, 27 patients (age range: 19–77 years) with AIH underwent liver MRI. T1 and T2 relaxation times as well as ECV were quantified by mapping techniques. The presence of significant fibrosis (≥ F2) was defined as magnetic resonance elastography (MRE)-based liver stiffness ≥ 3.66 kPa. MRE was used as reference standard, against which the diagnostic performance of MRI-derived mapping parameters was tested. Diagnostic performance was compared by utilizing receiver-operating characteristic (ROC) analysis. Results MRE-based liver stiffness correlated with both, hepatic native T1 (r = 0.69; P r = 0.80; P P > 0.05 for each comparison)). Conclusion Quantitative mapping parameters such as T1 and ECV can identify significant fibrosis in AIH patients. Future studies are needed to explore the value of parametric mapping for the evaluation of different disease stages.

We aimed to investigate the diagnostic utility of MRI extracellular volume fraction (ECV) for the assessment of liver cirrhosis severity as defined by Child-Pugh class. In this retrospective study, 90 patients (68 cirrhotic patients and 22 controls), who underwent multiparametric liver MRI, were identified. Hepatic T1 relaxation times and ECV were assessed. Clinical scores of liver disease severity were calculated. One-way analysis of variance (ANOVA) followed by Tukey's multiple comparison test, Spearman's correlation coefficient, and receiver operating characteristic (ROC) analysis were used for statistical analysis. In cirrhotic patients, hepatic native T1 increased depending on Child-Pugh class (620.5 ± 78.9 ms (Child A) vs. 666.6 ± 73.4 ms (Child B) vs. 828.4 ± 91.2 ms (Child C), P 0.001). ECV was higher in cirrhotic patients compared to the controls (40.1 ± 11.9% vs. 25.9 ± 4.5%, P 0.001) and increased depending of Child-Pugh class (33.3 ± 6.0% (Child A) vs. 39.6 ± 4.9% (Child B) vs. 52.8 ± 1.2% (Child C), P 0.001). ECV correlated with Child-Pugh score (r = 0.64, P 0.001). ECV allowed differentiating between Child-Pugh classes A and B, and B and C with an AUC of 0.785 and 0.944 (P 0.001, respectively). The diagnostic performance of ECV for differentiating between Child-Pugh classes A and B, and B and C was higher compared to hepatic native T1 (AUC: 0.651 and 0.910) and MELD score (AUC: 0.740 and 0.795) (P 0.05, respectively). MRI-derived ECV correlated with Child-Pugh score and had a high diagnostic performance for the discrimination of different Child-Pugh classes. ECV might become a valuable non-invasive biomarker for the assessment of liver cirrhosis severity.

Immune checkpoint inhibition suggests promising progress for the treatment of advanced hepatocellular carcinoma (HCC). However, the underlying cellular mechanisms remain unclear because liver cancer cells apparently do not upregulate inhibitory checkpoint molecules. Here, we analysed whether regulatory T cells (Tregs) can alternatively trigger checkpoint inhibition pathways in HCC. Using flow cytometry we analysed expression of checkpoint molecules (PD-1, PD-L1, CTLA-4, GITR, Tim-3) on peripheral CD4+CD25+Foxp3+ Tregs and their secretion of inhibitory mediators (IL-10, IL-35, TGF-beta, galectin-9) in 116 individuals (50 patients with HCC, 41 non-tumour bearing liver disease controls, 25 healthy controls). Functional activity of Tregs on T effector cells (IFN-gamma production, cytotoxicity) was characterized in vitro using a lectin-dependent cellular cytotoxicity (LDCC) assay against checkpoint inhibitor-negative P815 target cells. Unlike liver patients without malignancy and healthy controls, the frequency of checkpoint inhibitor-positive Tregs inversely correlated to age of patients with HCC (PD-L1, p = 0.0080; CTLA-4, p = 0.0029) and corresponded to enhanced numbers of Tregs producing IL-10 and IL-35 (p

HIV/HCV infection is supposed to substantially reduce survival as compared to HIV mono-infection. Here, we compared longtime-survival and causes of death in a cohort of HIV- and HIV/HCV-co-infected patients on combined antiretroviral therapy (cART), before introduction of HCV direct acting antivirals (DAA). 322 Caucasian patients with HIV (n = 176) and HIV/HCV-infection (n = 146) were enrolled into this study. All patients were recruited between 2003 and 2004 and followed until 01.01.2014. We compared overall survival between the two groups by the Kaplan-Meyer method and identified independent factors associated with long-time survival by conditional Cox regression analysis. In total 46 (14.3%) patients died during the observation period (HIV infection: n = 23 (13.1%), HIV/HCV infection: n = 23 (15.8%) but overall-survival did not differ significantly between HIV/HCV-infected and HIV mono-infected patients (p = 0.619). Survival was substantially better in patients with complete suppression of HIV replication below the level of detection than in those with residual viremia (p = 0.001). Age (p = 0.008), γ-glutamyltranspeptidase (p

The high genetic diversity of hepatitis C virus (HCV) complicates effective vaccine development. We screened a cohort of 435 HCV-infected individuals and found that 2%–5% demonstrated outstanding HCV-neutralizing activity. From four of these patients, we isolated 310 HCV antibodies, including neutralizing antibodies with exceptional breadth and potency. High neutralizing activity was enabled by the use of the VH1-69 heavy-chain gene segment, somatic mutations within CDRH1, and CDRH2 hydrophobicity. Structural and mutational analyses revealed an important role for mutations replacing the serines at positions 30 and 31, as well as the presence of neutral and hydrophobic residues at the tip of the CDRH3. Based on these characteristics, we computationally created a de novo antibody with a fully synthetic VH1-69 heavy chain that efficiently neutralized multiple HCV genotypes. Our findings provide a deep understanding of the generation of broadly HCV-neutralizing antibodies that can guide the design of effective vaccine candidates.

Background: De novo steatosis is the main criteria for non-alcoholic fatty liver disease (NAFLD), which is becoming a clinically relevant comorbidity in HIV-infected patients. This may be due to the HIV virus itself, as well as long-term toxicities deriving from antiretroviral therapy. Therefore, HIV infected patients require prevention and monitoring regarding NAFLD. Methods: This study investigated the differential role of body mass index (BMI) and combination antiretroviral treatment (cART) drugs on NAFLD progression. This single center prospective longitudinal observational study enrolled HIV monoinfected individuals between August 2013 to December 2018 with yearly visits. Each visit included liver stiffness and steatosis [defined as controlled attenuation parameter (CAP)>237 dB/m] assessment by annually transient elastography using an M- or XL-probe of FibroScan, and calculation of the novel FibroScan-AST (FAST) score. Risk factors for denovo/progressed steatosis and tripling of FAST-score increase were investigated using Cox regression model with time-dependent covariates. Findings: 319 monoinfected HIV positive patients with at least two visits were included into the study, of which 301 patients had at least two valid CAP measurements. 51·5%(155) patients did not have steatosis at first assessment, of which 45%(69) developed steatosis during follow-up. A BMI>23 kg/m2 (OR: 4·238, 95% CI: 2·078–8·938; p < 0·0001), tenofovir-alafenamid (TAF) (OR: 5·073, 95% CI: 2·362–10·899); p < 0·0001) and integrase strand transfer inhibitors (INSTI) (OR: 2·354, 95% CI: 1·370–4·048; p = 0·002), as well as type 2 diabetes mellitus (OR: 7·605, 95% CI: 2·315–24·981; p < 0·0001) were independent predictors of de novo steatosis in multivariable analysis. Tenofovir disoproxilfumarate (TDF) was associated with a lower risk for weight gain and steatosis progression/onset using CAP value (HR: 0·28, 95% CI: 0·12–0·64; p = 0·003) and FAST scores (HR: 0·31, 95% CI: 0·101–0·945; p = 0·04). Interpretation: Steatosis can develop despite non-obese BMI in patients with HIV monoinfection under cART, especially in male patients with BMI over 23 kg/m2. While TAF and INSTI increase the risk of progression of steatosis, TDF was found to be independently associated with a lower risk of a clinically significant weight gain and thereby, might slow down development and progression of steatosis. Funding: There was no additional funding received for this project. All funders mentioned in the ‘declaration of interests’ section had no influence on study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Background & Aims CD4 + regulatory T cells (Tregs) expand during chronic hepatitis C virus (HCV) infection, inhibit antiviral immunity and promote fibrosis. Direct-acting antiviral agents (DAA) have revolutionized HCV therapy. However, it is unclear if Tregs are normalized after DAA-induced HCV elimination. Methods We analyzed Tregs before (baseline), at end of therapy (EOT), 12 and 24weeks (SVR12, SVR24) and long-term (51±14weeks) after EOT in 26 genotype-1-infected patients who were successfully treated with sofosbuvir (SOF) plus interferon (IFN)/ribavirin (n=12) and IFN-free DAA regimens (SOF plus daclatasvir or simeprevir; n=14). Frequency, phenotype and suppressor function of peripheral Foxp3 + CD25 + CD4 + T cells were studied by multi-color flow cytometry and co-culture inhibition assays. Results Frequencies and activation status of Foxp3 + CD25 + CD4 + T cells remained elevated above those of normal controls in both treatment groups even long-term after HCV elimination. Co-culture assays indicated a dose-response relationship for functional inhibition of autologous CD4 + effector T cells and confirmed that activation of Tregs remained largely unchanged over the observation period. Unlike IFN-free regimens, SOF plus IFN/ribavirin induced a transiently increased frequency of Foxp3 + CD25 + CD4 + T cells at EOT (5.0% at baseline to 6.1% at EOT; p =0.001). These Foxp3 + CD25 + CD4 + T cells co-expressed the activation markers glycoprotein A repetitions predominant (GARP; p =0.012) and tumor necrosis factor receptor superfamily, member 4 (OX-40; p =0.001) but showed unchanged in vitro inhibitory activity. Conclusion Although IFN-based DAA therapy induced transient expansion of activated Foxp3 + CD25 + CD4 + T cells, neither IFN-based nor IFN-free DAA regimens normalized frequencies and activation status of Tregs one year after viral elimination. Persistence of immunosuppressive Tregs may thus contribute to complications of liver disease even long-term after HCV cure. Lay summary In chronic hepatitis C virus (HCV) infection, CD4 + regulatory T cells (Tregs) can reduce antiviral immune responses, promote liver fibrosis and may increase the risk for liver cancer, because they gradually expand during disease. Modern direct-acting antiviral agents (DAA) can "cure" hepatitis C in almost all treated patients. However, our study shows that DAA do not normalize the increased frequency and activation status of Tregs even long-term after HCV elimination. Tregs may persistently modulate functions of the immune system even after "cure" of hepatitis C.

Background: Severe hepatic steatosis shows a high prevalence and contributes to morbidity and mortality in human immunodeficiency virus (HIV) infected patients. Known risk factors include obesity, dyslipidaemia and features of metabolic syndrome. Fibroblast growth factor 21 (FGF-21) is involved with hepatic glucose and lipid metabolism. This study aimed to evaluate FGF-21 as a biomarker for severe hepatic steatosis in non-obese HIV-infected patients. Methods: This is a prospective, cross-sectional, monocentric study including HIV-infected out-patients. Hepatic steatosis was measured via controlled attenuation parameter (CAP) using FibroScan 502 touch (ECHOSENS, France). Severe hepatic steatosis was defined at CAP ≥ 253 dB/m. Peripheral blood samples were collected and plasma was analysed for FGF-21. Demographic and clinical characteristics were collected from patient's health records. Results: In total, 73 non-obese HIV-monoinfected patients were included in this study. Prevalence of severe hepatic steatosis was 41%. Patients with severe hepatic steatosis showed significantly higher levels of FGF-21. Univariate analysis revealed FGF-21, BMI, hyperlipidaemia, ALT levels and arterial hypertension as significant, while multivariate analysis showed only FGF-21, arterial hypertension and ALT levels as significant independent risk factors for severe hepatic steatosis. Conclusion: This study presents FGF-21 as an independent and stronger predictor of severe hepatic steatosis than blood lipids in HIV-infected patients. Moreover, arterial hypertension and ALT levels predict severe steatosis even in non-obese HIV-monoinfected patients. Furthermore, this study supports existing metabolic risk factors and expands them to non-obese HIV-infected patients.

Background & Aims Induction of cross-reactive antibodies targeting conserved epitopes of the envelope proteins E1E2 is a key requirement for an hepatitis C virus vaccine. Conserved epitopes like the viral CD81-binding site are targeted by rare broadly neutralizing antibodies. However, these viral segments are occluded by variable regions and glycans. We aimed to identify antigens exposing conserved epitopes and to characterize their immunogenicity. Methods We created hepatitis C virus variants with mutated glycosylation sites and/or hypervariable region 1 (HVR1). Exposure of the CD81 binding site and conserved epitopes was quantified by soluble CD81 and antibody interaction and neutralization assays. E2 or E1-E2 heterodimers with mutations causing epitope exposure were used to immunize mice. Vaccine-induced antibodies were examined and compared with patient-derived antibodies. Results Mutant viruses bound soluble CD81 and antibodies targeting the CD81 binding site with enhanced efficacy. Mice immunized with E2 or E1E2 heterodimers incorporating these modifications mounted strong, cross-binding, and non-interfering antibodies. E2-induced antibodies neutralized the autologous virus but they were not cross-neutralizing. Conclusions Viruses lacking the HVR1 and selected glycosylation sites expose the CD81 binding site and cross-neutralization antibody epitopes. Recombinant E2 proteins carrying these modifications induce strong cross-binding but not cross-neutralizing antibodies. Lay summary Conserved viral epitopes can be made considerably more accessible for binding of potently neutralizing antibodies by deletion of hypervariable region 1 and selected glycosylation sites. Recombinant E2 proteins carrying these mutations are unable to elicit cross-neutralizing antibodies suggesting that exposure of conserved epitopes is not sufficient to focus antibody responses on production of cross-neutralizing antibodies.

Supplemental Digital Content is available in the text, Prevalence and risk factors for hepatic steatosis (HS) in the human immunodeficiency virus (HIV)-positive population of western countries are controversially discussed and potentially confounded by coinfection with viral hepatitis. Significant HS (more than 10% of hepatocytes) can be accurately assessed using controlled attenuation parameter (CAP) determination. Aim of this study was to assess prevalence and factors associated with significant HS in HIV monoinfected patients. A total of 364 HIV-infected patients (289 monoinfected) were included in this prospective, cross-sectional study. All patients underwent CAP determination. Steatosis was classified as S1 (significant steatosis) with CAP > 238 dB/m, S2 with CAP > 260 dB/m, and S3 with CAP > 292 dB/m. Multivariable logistic regression analyses were performed to assess the factors associated with HS in this cohort. Significant HS was detected in 118 monoinfected patients (149 in the total cohort). In the total cohort as well as in the monoinfected patients alone, HS grade distribution showed a similar pattern (S1:29%, S2:34%, and S3:37%). Interestingly, patients with HS had a longer history of HIV infection and combined antiretroviral therapy (cART). Interalia, age, gender, ethnicity, and metabolic factors were strongly associated with HS, while body mass index (BMI), triglyceride, and glycated hemoglobin (HbA1c) levels were independently associated with significant HS. HS is highly prevalent among HIV monoinfected patients. Although metabolic risk factors, such as obesity and poorly controlled diabetes, are independently associated with HS in HIV monoinfected patients, cART and control of HIV seem to play an indirect role in the development of HS, probably through the return-to-health effect.

CD4We analyzed Tregs before (baseline), at end of therapy (EOT), 12 and 24weeks (SVR12, SVR24) and long-term (51±14weeks) after EOT in 26 genotype-1-infected patients who were successfully treated with sofosbuvir (SOF) plus interferon (IFN)/ribavirin (n=12) and IFN-free DAA regimens (SOF plus daclatasvir or simeprevir; n=14). Frequency, phenotype and suppressor function of peripheral Foxp3Frequencies and activation status of Foxp3Although IFN-based DAA therapy induced transient expansion of activated Foxp3In chronic hepatitis C virus (HCV) infection, CD4

Background Initiation of combined antiretroviral therapy (cART) has markedly increased survival and quality of life in HIV-infected patients. With the advent of new treatment options, including an increasing number of single-tablets, the durability of first-line ART regimes is developing. Methods We used data from the prospective multicenter German Clinical Surveillance of HIV Disease (ClinSurv) cohort of the Robert-Koch-Institute. Time to event was calculated as time between initiation of first-line cART and therapy change. We used a Cox model to assess predictors of treatment change 1 year after starting cART. Results We included 6,894 patients who initiated ART between 2005 and 2014. The sample population was predominantly men (79%) with German origin (69.8%), of which 49.6% were reporting sex with men (MSM) as main risk factor. Median age (IQR) was 38 (31–46) years. The most frequently treatment combinations were 2NRTI/PIr (48.1%) and 2NRTI/1NNRTI (42.2%), 2NRTI/1II (5.2%). 22.6% patients changed their first-line treatment within 1 year. Median (IQR) length between first intake and stop of the regime was 105 (35–214) days, which did not change significantly between 2005 (108; 38–217) and 2014 (128; 74–200) (P = 0.28). Most common documented causes were side effects of drugs 418 (44.0%) and non-adherence 173 (18.2%). In the Cox model (Figure 1), we identified numerous covariates associated with discontinuation of the first-line regime. A 2NRTI/1NNRTI regime was associated with higher rates (hazard ratio [HR] 1.28, 95% CI 1.06–1.55) and a 2NRTI/1II regime with lower rates (HR 0.34, 95% CI 0.23–0.51) of treatment modification (ref.: 2NRTI/1PIr). The HR increased markedly with the amount of daily-administered tablets from HR 2.15, 95% CI 1.48–3.11 (2–3 tablets) to HR 3.98, 95% CI 2.16–7.31 (10 tablets) (ref.: one tablet). We observed an association with a baseline viral load (VL) of >100 copies/mL (HR 0.65, 95% CI 0.53–0.81) and >100.000 copies/mL (HR 0.68, 95% CI 0.54–0.85) (ref.: VL > 1 Mio. copies/mL). Conclusion Our analysis revealed, that side effects of drugs, the number of tablets per day and the VL at baseline are significantly associated with treatment change within the first year. A first-line regime with 2NRTI/1II seems to improve the adherence to the initial regime significantly. Disclosures All authors: No reported disclosures.

PLoS one 12(6), e0178685 - (2017). doi:10.1371/journal.pone.0178685, Published by PLoS, Lawrence, Kan.