TLR ligands of ryegrass pollen microbial contaminants enhance Th1 and Th2 responses and decrease induction of Foxp3hi regulatory T cells

Microbial contamination of grass pollens could affect sensitization, subsequent allergic response, and efficacy of allergen‐specific immunotherapy. We investigated whether bacterial immunomodulatory substances can direct PBMC responses of allergic and nonatopic subjects against ryegrass pollen (RGP) toward Th1, Th2, or regulatory T (Treg) cells. Aqueous extracts of RGP with high or low LPS were fractionated into large and small molecular weight (MW) components by diafiltration. CFSE‐labeled PBMCs from allergic and nonatopic subjects were stimulated with RGP extracts (RGPEs) and analyzed for cytokine secretion and T‐cell responses. High LPS RGPE increased IFN‐γ⁺ Th1 and IL‐4⁺ Th2 effector cell induction and consistently decreased CD4⁺Foxp3^hi Treg‐cell induction. IL‐10‐producing T‐cell frequency was unaltered, but IL‐10 secretion was increased by high LPS RGPE. RGPE‐stimulation of TLR‐transfected cell lines revealed that high LPS pollen also contained a TLR2‐ligand, and both batches a TLR9‐ligand. Beta‐1,3‐glucans were detected in large and small MW fractions and were also T‐cell stimulatory. In conclusion, coexposure to allergen and proinflammatory microbial stimuli does not convert an established Th2‐ into a Th1‐response. Instead, proinflammatory responses are exacerbated and Foxp3^hi Treg‐cell induction is decreased. These findings show that adjuvants for specific immunotherapy should enhance Treg cells rather than target immune deviation from Th2 to Th1.     

Syntaxin 11 is required for NK and CD8+ T‐cell cytotoxicity and neutrophil degranulation

Syntaxin 11 (STX11) controls vesicular trafficking and is a key player in exocytosis. Since Stx11 mutations are causally associated with a familial hemophagocytic lymphohistio‐cytosis, we wanted to clarify whether STX11 is functionally important for key immune cell populations. This was studied in primary cells obtained from newly generated Stx11^?/? mice. Our data revealed that STX11 is not only widely expressed in different immune cells, but also induced upon LPS or IFN‐γ treatment. However, Stx11 deficiency does not affect macrophage phagocytic function and cytokine secretion, mast cell activation, or antigen presentation by DCs. Instead, STX11 selectively controls lymphocyte cytotoxicity in NK and activated CD8⁺ T cells and degranulation in neutrophils. Stx11^?/? NK cells and CTLs show impaired degranulation, despite a comparable activation, maturation and expression of the complex‐forming partners MUNC18–2 and VTI1B. In addition, Stx11^?/? CTLs and NK cells produce abnormal levels of IFN‐γ. Since functional reconstitution rescues the defective phenotype of Stx11^?/? CTLs, we suggest a direct, specific and key role of STX11 in controlling lymphocyte cytotoxicity, cytokine production and secretion. Finally, we show that these mice are a very useful tool for dissecting the role of STX11 in vesicular trafficking and secretion.     

Long-Term Carriage of Vancomycin-Resistant Enterococci in Patients Discharged from Hospitals: a 12-Year Retrospective Cohort Study

Contact precautions are recommended in hospitals to prevent the transmission of vancomycin-resistant enterococci (VRE); however, there is no clear policy for how long patients should be under contact precautions due to a lack of information on the duration of carriage of these organisms. We conducted a retrospective cohort study to understand the duration of carriage of VRE (by screening of a single stool culture) and associated factors among patients who had been identified with VRE infection and/or colonization since the year 2000 at our health facilities. Of the 345 eligible participants, 136 did not respond, 90 declined to participate, and 16 did not send in the required specimens. Of the 103 remaining participants, 13 were found to have current VRE fecal carriage. The proportion of colonized patients fell from 40% (2/5) in the first year to 23.3% (7/30) in year 4. None of the 40 patients who had VRE detected >4 years prior were found to be colonized at the time of the study. The longest duration of detected VRE positivity was 46.5 months. Univariate analysis revealed that recent exposure to any antibiotics (P = 0.016), multiple antibiotics (P = 0.001), amoxicillin-clavulanic acid (P = 0.021), piperacillin-tazobactam (P = 0.007), glycopeptides (P < 0.001), meropenem (P = 0.007), aminoglycosides (P = 0.021), or fluoroquinolones (P = 0.021), being the index case in a clinical specimen (P = 0.016), and recent hospitalization (P < 0.001) were significantly associated with continued carriage on follow-up. In the surviving outpatients, a significant proportion appeared to clear VRE carriage. Our results suggest that in the absence of recent risk factors, such as hospitalization or antibiotic use, patients with a remote history of colonization (>4 years) may no longer require contact isolation precautions.     

Effect of “Speak Up” educational tools to engage patients in advance care planning in outpatient healthcare settings: A prospective before-after study

BackgroundTools for advance care planning (ACP) are advocated to help ensure patient values guide healthcare decisions. Evaluation of the effect of tools introduced to patients in clinical settings is needed.ObjectiveTo evaluate the effect of the Canadian Speak Up Campaign tools on engagement in advance care planning (ACP), with patients attending outpatient clinics.Patient involvement: Patients were not involved in the problem definition or solution selection in this study but members of the public were involved in development of tools. The measurement of impacts involved patients.MethodsThis was a prospective pre-post study in 15 primary care and two outpatient cancer clinics. The outcome was scores on an Advance Care Planning Engagement Survey measuring Behavior Change Process on 5-point scales and Actions (0?21-point scale) administered before and six weeks after using a tool, with reminders at two or four weeks.Results177 of 220 patients (81%) completed the study (mean 68 years of age, 16% had cancer). Mean Behavior Change Process scores were 2.9 at baseline and 3.5 at follow-up (mean change 0.6, 95% confidence interval 0.5 to 0.7; large effect size of 0.8). Mean Action Measure score was 3.7 at baseline and 4.8 at follow-up (mean change 1.1, 95% confidence interval 0.6–1.5; small effect size of 0.2).Practical valuePublicly available ACP tools may have utility in clinical settings to initiate ACP among patients. More time and motivation may be required to stimulate changes in patient behaviors related to ACP.     

A potent small molecule inhibits polyglutamine aggregation in Huntington's disease neurons and suppresses neurodegeneration in vivo

Polyglutamine (polyQ) disorders, including Huntington's disease (HD), are caused by expansion of polyQ-encoding repeats within otherwise unrelated gene products. In polyQ diseases, the pathology and death of affected neurons are associated with the accumulation of mutant proteins in insoluble aggregates. Several studies implicate polyQ-dependent aggregation as a cause of neurodegeneration in HD, suggesting that inhibition of neuronal polyQ aggregation may be therapeutic in HD patients. We have used a yeast-based high-throughput screening assay to identify small-molecule inhibitors of polyQ aggregation. We validated the effects of four hit compounds in mammalian cell-based models of HD, optimized compound structures for potency, and then tested them in vitro in cultured brain slices from HD transgenic mice. These efforts identified a potent compound (IC50=10 nM) with long-term inhibitory effects on polyQ aggregation in HD neurons. Testing of this compound in a Drosophila HD model showed that it suppresses neurodegeneration in vivo, strongly suggesting an essential role for polyQ aggregation in HD pathology. The aggregation inhibitors identified in this screen represent four primary chemical scaffolds and are strong lead compounds for the development of therapeutics for human polyQ diseases.     

ISPD Cardiovascular and Metabolic Guidelines in Adult Peritoneal Dialysis Patients Part I – Assessment and Management of Various Cardiovascular Risk Factors

Cardiovascular disease contributes significantly to the adverse clinical outcomes of peritoneal dialysis (PD) patients. Numerous cardiovascular risk factors play important roles in the development of various cardiovascular complications. Of these, loss of residual renal function is regarded as one of the key cardiovascular risk factors and is associated with an increased mortality and cardiovascular death. It is also recognized that PD solutions may incur significant adverse metabolic effects in PD patients. The International Society for Peritoneal Dialysis (ISPD) commissioned a global workgroup in 2012 to formulate a series of recommendations regarding lifestyle modification, assessment and management of various cardiovascular risk factors, as well as management of the various cardiovascular complications including coronary artery disease, heart failure, arrhythmia (specifically atrial fibrillation), cerebrovascular disease, peripheral arterial disease and sudden cardiac death, to be published in 2 guideline documents. This publication forms the first part of the guideline documents and includes recommendations on assessment and management of various cardiovascular risk factors. The documents are intended to serve as a global clinical practice guideline for clinicians who look after PD patients. The ISPD workgroup also identifies areas where evidence is lacking and further research is needed.     

Anesthesia and the developing brain: a way forward for clinical research

It is now well established that many general anesthetics have a variety of effects on the developing brain in animal models. In contrast, human cohort studies show mixed evidence for any association between neurobehavioural outcome and anesthesia exposure in early childhood. In spite of large volumes of research, it remains very unclear if the animal studies have any clinical relevance; or indeed how, or if, clinical practice needs to be altered. Answering these questions is of great importance given the huge numbers of young children exposed to general anesthetics. A recent meeting in Genoa brought together researchers and clinicians to map a path forward for future clinical studies. This paper describes these discussions and conclusions. It was agreed that there is a need for large, detailed, prospective, observational studies, and for carefully designed trials. It may be impossible to design or conduct a single study to completely exclude the possibility that anesthetics can, under certain circumstances, produce long‐term neurobehavioural changes in humans; however , observational studies will improve our understanding of which children are at greatest risk, and may also suggest potential underlying etiologies, and clinical trials will provide the strongest evidence to test the effectiveness of different strategies or anesthetic regimens with respect to better neurobehavioral outcome.     

Cost-effectiveness of testing for hypercoagulability and effects on treatment strategies in patients with deep vein thrombosis

PURPOSE: Among patients with deep vein thrombosis, hypercoagulable conditions impart a substantial risk of recurrent thrombosis. We sought to determine the cost-effectiveness of testing for these disorders, as well as which tests should be selected and how results should be used. METHODS: Using a Markov state-transition model, strategies of testing or not testing for a hypercoagulable state followed by anticoagulation for 6 to 36 months were compared in a hypothetical cohort of patients with apparently idiopathic deep vein thrombosis who were followed for life. Strategies were compared based on lifetime costs, quality-adjusted life-years (QALYs), and marginal cost-effectiveness. RESULTS: In the base case, testing followed by 24 months of anticoagulation in patients with a hypercoagulable condition was more cost-effective ($54,820; 23.76 QALYs) than usual care, which comprised 6 months of anticoagulation without testing ($55,260; 23.72 QALYs). All hypercoagulable conditions tested were common enough and associated with a sufficient risk of recurrence to justify inclusion in a test panel. Twenty-four months of initial anticoagulation was preferred (<$50,000/QALY) for most conditions, whereas lifetime anticoagulation was preferred for patients with antiphospholipid antibody syndrome ($2928/QALY) or homozygous factor V Leiden mutation ($3804/QALY). Models using newer evidence on recurrence suggested 18 to 36 months of anticoagulation without testing as the preferred approach. CONCLUSION: Testing for hypercoagulable disorders in patients with idiopathic deep vein thrombosis followed by 2 years of anticoagulation in affected patients is cost-effective. A simpler approach of treating all patients with prolonged anticoagulation without testing is justified if data confirm the persistent risk of recurrent thrombosis.