Mucosal-associated invariant T (MAIT) cells comprise a subpopulation of T cells that can be activated by bacterial products and cytokines to produce IFN-γ. Since little is known on MAIT cells during ...HCV infection, we compared their phenotype and function in comparison to HIV and HCV/HIV co-infected patients, and determined the effect of IFN-α-based and direct-acting antiviral therapy on MAIT cells of HCV patients.
Blood samples from patients with chronic HCV (CHCV), virologically suppressed HIV, acute HCV/HIV co-infection (AHCV/HIV) and healthy individuals were examined by flowcytometry for phenotype and function of MAIT and NK cells.
Compared to healthy individuals, the frequency of CD161+Vα7.2+ MAIT cells was significantly decreased in patients with CHCV, HIV and AHCV/HIV co-infection. CD38 expression on MAIT cells was increased in AHCV/HIV patients. MAIT cells were responsive to IFN-α in vitro as evidenced by enhanced frequencies of IFN-γ producing cells. IFN-α-based therapy for CHCV decreased the frequency of IFN-γ+ MAIT cells, which was still observed 24 weeks after successful therapy. Importantly, even after successful IFN-α-based as well as IFN-α-free therapy for CHCV, decreased frequencies of MAIT cells persisted. We show that the frequencies of MAIT cells are reduced in blood of patients with CHCV, HIV and in AHCV/HIV co-infection compared to healthy individuals. Successful therapy for CHCV did not normalize MAIT cell frequencies at 24 weeks follow up. The impact of HIV and HCV infection on the numbers and function of MAIT cells warrant further studies on the impact of viral infections and the antimicrobial function of MAIT cells.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background & Aims Weak hepatitis C virus (HCV) specific immunity in peripheral blood has been shown to be partially controlled by regulatory T cells (Treg). However, little is known about Treg ...present in livers of HCV-infected patients, their association with clinical parameters, and immunopathology resulting in disease progression. Methods The frequency and phenotype of CD4+FoxP3+ Treg, conventional CD4+ T cells, and the distribution of lymphocytes and leukocytes were studied by multi-color flowcytometry in liver and peripheral blood of 43 chronic HCV patients at different phases of liver disease. Comparisons between healthy blood and liver and correlations with disease parameters were made. Results An extensive lymphocyte infiltration containing abundant numbers of CD4+FoxP3+ Treg was present in HCV-infected livers, while absent from healthy liver. Moreover, in all patients, intrahepatic CD4+FoxP3+ Treg showed a fully differentiated and highly activated phenotype on the basis of the surface markers CD45RO, CCR7, CTLA-4 and HLA-DR. These Treg were more numerous in those HCV-infected livers showing only limited fibrosis. However, HCV RNA loads or alanine transaminase levels did not correlate with CD4+FoxP3+ Treg frequencies. Conclusions Our data demonstrate that large numbers of highly activated and differentiated CD4+FoxP3+ Treg localize to the infiltrated chronic HCV-infected liver and may result in limiting the extent of fibrosis. This suggests that CD4+FoxP3+ Treg play a pivotal role in limiting collateral damage by suppressing excessive HCV-induced immune activation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Key points
The post‐exercise recovery of phosphocreatine, a measure of the oxidative capacity of muscles, as assessed by 31P MR spectroscopy, shows a striking increase from distal to proximal along ...the human tibialis anterior muscle.
To investigate why this muscle exhibits a greater oxidative capacity proximally, we tested whether the spatial variation in phosphocreatine recovery rate is related to oxygen supply, muscle fibre type or type of exercise.
We revealed that oxygen supply also increases from distal to proximal along the tibialis anterior, and that it strongly correlated with phosphocreatine recovery. Carnosine level, a surrogate measure for muscle fibre type was not different between proximal and distal, and type of exercise did not affect the gradient in phosphocreatine recovery rate.
Taken together, the findings of this study suggest that the post‐exercise spatial gradients in oxygen supply and phosphocreatine recovery are driven by a higher intrinsic mitochondrial oxidative capacity proximally.
Phosphorus magnetic resonance spectroscopy (31P MRS) of human tibialis anterior (TA) revealed a strong proximo‐distal gradient in the post‐exercise phosphocreatine (PCr) recovery rate constant (kPCr), a measure of muscle oxidative capacity. The aim of this study was to investigate whether this kPCr gradient is related to O2 supply, resting phosphorylation potential, muscle fibre type, or type of exercise. Fifteen male volunteers performed continuous isometric ankle dorsiflexion at 30% maximum force until exhaustion. At multiple locations along the TA, we measured the oxidative PCr resynthesis rate (VPCr = kPCr × PCr depletion) by 31P MRS, the oxyhaemoglobin recovery rate constant (kO2Hb) by near infrared spectroscopy, and muscle perfusion with MR intravoxel incoherent motion imaging. The kO2Hb, kPCr, VPCr and muscle perfusion depended on measurement location (P < 0.001, P < 0.001, P = 0.032 and P = 0.003, respectively), all being greater proximally. The kO2Hb and muscle perfusion correlated with kPCr (r = 0.956 and r = 0.852, respectively) and VPCr (r = 0.932 and r = 0.985, respectively), the latter reflecting metabolic O2 consumption. Resting phosphorylation potential (PCr/inorganic phosphate) was also higher proximally (P < 0.001). The surrogate for fibre type, carnosine content measured by 1H MRS, did not differ between distal and proximal TA (P = 0.884). Performing intermittent exercise to avoid exercise ischaemia, still led to larger kPCr proximally than distally (P = 0.013). In conclusion, the spatial kPCr gradient is strongly associated with the spatial variation in O2 supply. It cannot be explained by exercise‐induced ischaemia nor by fibre type. Our findings suggest it is driven by a higher proximal intrinsic mitochondrial oxidative capacity, apparently to support contractile performance of the TA.
Key points
The post‐exercise recovery of phosphocreatine, a measure of the oxidative capacity of muscles, as assessed by 31P MR spectroscopy, shows a striking increase from distal to proximal along the human tibialis anterior muscle.
To investigate why this muscle exhibits a greater oxidative capacity proximally, we tested whether the spatial variation in phosphocreatine recovery rate is related to oxygen supply, muscle fibre type or type of exercise.
We revealed that oxygen supply also increases from distal to proximal along the tibialis anterior, and that it strongly correlated with phosphocreatine recovery. Carnosine level, a surrogate measure for muscle fibre type was not different between proximal and distal, and type of exercise did not affect the gradient in phosphocreatine recovery rate.
Taken together, the findings of this study suggest that the post‐exercise spatial gradients in oxygen supply and phosphocreatine recovery are driven by a higher intrinsic mitochondrial oxidative capacity proximally.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract Sustained immune activation during chronic HIV infection is considered to augment co-morbidity and mortality. Effective combination antiretroviral therapy (cART) has shown to dampen immune ...activation especially during the first year cART, but the effects of long-term cART in patients without major comorbidities remains under-investigated. We performed a comprehensive analysis including cellular, intracellular and plasma biomarkers to study the effect of cART on immune parameters in 5 groups of 10 HIV patients. All patients were without major co-morbidities and grouped based on cART duration (0, 1, 3, 5, and 10 years). We included 10 matched healthy controls for comparison. Our data show that after the first year of cART, no additional effect on the level of inflammatory markers is observed in HIV infected patients without major co morbidities. Residual immune activation status in well-treated HIV-infection is similar to levels observed in healthy controls.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background: In the Netherlands, unrestricted access to direct-acting antivirals (DAAs) halved the incidence of acute hepatitis C virus (HCV) infections among HIV-infected men who have sex with men ...(MSM). To develop strategies that can further reduce the spread of HCV, it is important to understand the transmission dynamics of HCV. We used phylogenetic analysis of a dense sample of MSM to provide insight into the impact of unrestricted access to DAAs on HCV transmission in the Netherlands and in Belgium. Methods: We included 89 MSM that were recently infected with HCV genotype 1a in ten Dutch and one Belgian HIV treatment centers. Sequences were generated using next gene sequencing and Sanger sequencing. Maximum likelihood phylogenetic analysis (general time reversible model) was performed on concatenated NS5A and NS5B sequences and a reference set of 389 highly similar control sequences selected from GenBank. A cluster was based on a minimum bootstrap support of 90% and a 3% genetic distance threshold. Results: We found that 78 (88%) of individuals were part of seven major clusters. All clusters included individuals from across the study region, however, different cities were part of different clusters. In three clusters, HIV-negative MSM clustered with sequences from HIV-positive MSM. All clusters that were observed before the introduction of DAAs persisted after unrestricted access to DAAs became available. Conclusion: Recently acquired HCV infections among MSM in the Netherlands and Belgium are strongly clustered and therefore highly suitable for targeted prevention strategies, such as contact tracing and partner notification. Importantly, despite an HCV incidence reduction after high DAA uptake and continuously monitoring, HCV transmission persisted in the same clusters.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Sub-Saharan African (SSA) ethnicity has been associated with a higher risk of hepatocellular carcinoma (HCC) among individuals with chronic hepatitis B in cross-sectional studies. However, the ...incidence of HCC and performance of HCC risk scores in this population are unknown.
We conducted an international multicenter retrospective cohort study of all consecutive HBV-monoinfected individuals of SSA or Afro-Surinamese (AS) ethnicity managed at sites in the Netherlands, the United Kingdom and Spain. We assessed the 5- and 10-year cumulative incidences of HCC in the overall study population, among different clinically relevant subgroups and across (m)PAGE-B subgroups. Next, we explored the different risk factors for HCC.
During a median follow-up of 8 years, we analyzed 1,473 individuals of whom 34 developed HCC. The 5- and 10-year cumulative incidences of HCC were 1% and 2.4%. The 10-year cumulative incidence of HCC was 0.7% among individuals without advanced fibrosis at baseline, compared to 12.1% among individuals with advanced fibrosis (p <0.001). Higher age (adjusted hazard ratio aHR 1.05), lower platelet count (aHR 0.98), lower albumin level (aHR 0.90) and higher HBV DNA log10 (aHR 1.21) were significantly associated with HCC development. The 10-year cumulative incidence of HCC was 0.5% among individuals with a low PAGE-B score, compared to 2.9% in the intermediate- and 15.9% in the high-risk groups (p <0.001).
In this unique international multicenter cohort of SSA and AS individuals with chronic hepatitis B, we observed 5- and 10-year cumulative HCC risks of 1% and 2.4%, respectively. The risk of HCC was negligible for individuals without advanced fibrosis at baseline, and among individuals with low baseline (m)PAGE-B scores. These findings can be used to guide HCC surveillance strategies.
Sub-Saharan African ethnicity has been associated with a higher risk of hepatocellular carcinoma among individuals with chronic hepatitis B. In this international multicenter cohort study of sub-Saharan African and Afro-Surinamese individuals living with chronic hepatitis B in Europe, we observed 5- and 10-year cumulative incidences of hepatocellular carcinoma of 1% and 2.4%, respectively. The risk was negligible among individuals without advanced fibrosis and a low baseline (m)PAGE-B score. These findings can be used to guide HCC surveillance strategies in this population.
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•We found a 5- and 10-year cumulative HCC incidence of 1% and 2.4%.•Older age, higher HBV DNA levels, lower platelet count, and lower albumin levels increased the risk of HCC.•The 10-year HCC risk was negligible for individuals without advanced fibrosis at baseline.•The 10-year HCC risk was negligible for individuals with low baseline (m)PAGE-B scores.•These findings suggest opportunities for individualized HCC surveillance strategies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Antimicrobial stewardship (AMS) teams are responsible for performing an AMS programme in their hospitals that aims to improve the quality of antibiotic use. Measuring the quality of antimicrobial use ...is a core task of a stewardship team. Measurement provides insight into the current quality of antibiotic use and allows for the establishment of goals for improvement. Yet, a practical description of how such a quality measurement using quality indicators (QIs) should be performed is lacking.
To provide practical guidance on how a stewardship team can use QIs to measure the quality of antibiotic use in their hospital and identify targets for improvement.
General principles from implementation science, peer-reviewed publications, and experience from clinicians and researchers with AMS experience.
We provide step-by-step guidance on how AMS teams can use QIs to measure the quality of antibiotic use. The principles behind each step are explained and illustrated with the description and results of an audit of patients receiving outpatient parenteral antimicrobial therapy in four Dutch hospitals.
Improving the quality of antibiotic use is impossible without first gaining insight into that quality by performing a measurement with validated QIs. This step-by-step practice example of how to use quality indicators in a hospital will help AMS teams to identify targets for improvement. This enables them to perform their AMS programme more effectively and efficiently.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
There is an ongoing debate regarding whether low-level viremia (LLV), in particular persistent LLV, during HIV treatment with optimal adherence originates from low-level viral replication, viral ...production, or both. We performed an observational study in 30 individuals with LLV who switched to a boosted darunavir (DRV)-based therapy. In-depth virological analyses were used to characterize the viral population and the (activity) of the viral reservoir. Immune activation was examined using cell-bound and soluble markers. The primary outcome was defined as the effect on HIV-RNA and was categorized by responders (<50 cp/mL) or non-responders (>50 cp/mL). At week 24, 53% of the individuals were considered responders, 40% non-responders, and 7% could not be assigned. Sequencing showed no evolution or selection of drug resistance in the non-responders. Production of defective virus with mutations in either the protease (D25N) or RT active site contributed to persistent LLV in two individuals. We show that in about half of the study participants, the switch to a DRV-based regimen resulted in a viral response indicative of ongoing low-level viral replication as the cause of LLV before the switch. Our data confirm that in clinical management, high genetic barrier drugs like DRV are a safe choice, irrespective of the source of LLV.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Background & Aims
Mucosal‐associated invariant T (MAIT) cells are important innate T cells with antimicrobial and immunoregulatory activity, recently found to be depleted in blood of patients with ...HIV and HCV mono‐infections. In this study, we assessed the impact of HIV, HCV and HCV/HIV co‐infection on circulating and intrahepatic MAIT‐cells and correlations with liver fibrosis.
Methods
In this cross‐sectional study, nine healthy subjects, nine HIV, 20 HCV and 22 HCV/HIV co‐infected patients were included. Blood and liver fine needle aspirate biopsies were studied using flowcytometry for CD3+CD161+Vα7.2+ MAIT‐cell frequency, phenotype and function in HCV mono‐infected and HCV/HIV co‐infected patients without or with mild fibrosis (Metavir‐score F0‐F1) or severe fibrosis to cirrhosis (Metavir‐score F3‐F4).
Results
Circulating MAIT‐cells were decreased in blood of HCV, HIV and HCV/HIV patients with F0‐F1. In HCV/HIV co‐infected individuals with severe fibrosis to cirrhosis, the frequency of circulating MAIT‐cells was even further depleted, whereas their function was comparable to HCV/HIV co‐infected patients with low or absent fibrosis. In contrast, in HCV mono‐infected patients, MAIT‐cell frequencies were not related to fibrosis severity; however, MAIT‐cell function was impaired in mono‐infected patients with more fibrosis. More advanced liver fibrosis in HCV or HCV/HIV‐infected patients was not reflected by increased accumulation of MAIT‐cells in the affected liver.
Conclusions
Severe liver fibrosis is associated with dysfunctional MAIT‐cells in blood of HCV mono‐infected patients, and lower MAIT frequencies in blood of HCV/HIV co‐infected patients, without evidence for accumulation in the liver.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
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