ABSTRACT
Emerging evidence supports that mitochondrial dysfunction contributes to systemic lupus erythematosus (SLE) pathogenesis. Here we show that programmed mitochondrial removal, a hallmark of mammalian erythropoiesis, is defective in SLE. Specifically, we demonstrate that during human erythroid cell maturation, a hypoxia-inducible factor (HIF)-mediated metabolic switch is responsible for the activation of the ubiquitin-proteasome system (UPS), which precedes and is necessary for the autophagic removal of mitochondria. A defect in this pathway leads to accumulation of red blood cells (RBCs) carrying mitochondria (Mito+ RBCs) in SLE patients and in correlation with disease activity. Antibody-mediated internalization of Mito+ RBCs induces type I interferon (IFN) production through activation of cGAS in macrophages. Accordingly, SLE patients carrying both Mito+ RBCs and opsonizing antibodies display the highest levels of blood IFN-stimulated gene (ISG) signatures, a distinctive feature of SLE.
Subject(s)
Interferon Type I/metabolism , Lupus Erythematosus, Systemic/metabolism , Mitochondria/metabolism , Myeloid Cells/metabolism , Adolescent , Basic Helix-Loop-Helix Transcription Factors/metabolism , Child , Child, Preschool , Erythroblasts/metabolism , Erythroblasts/ultrastructure , Erythrocytes/metabolism , Erythropoiesis , Humans , Mitophagy , Proteasome Endopeptidase Complex/metabolism , Ubiquitin/metabolismABSTRACT
The nascent polypeptide-associated complex (NAC) is a conserved ribosome-associated protein biogenesis factor. Whether NAC exerts chaperone activity and whether this function is restricted to de novo protein synthesis is unknown. Here, we demonstrate that NAC directly exerts chaperone activity toward structurally diverse model substrates including polyglutamine (PolyQ) proteins, firefly luciferase, and Aß40. Strikingly, we identified the positively charged ribosome-binding domain in the N terminus of the ßNAC subunit (N-ßNAC) as a major chaperone entity of NAC. N-ßNAC by itself suppressed aggregation of PolyQ-expanded proteins in vitro, and the positive charge of this domain was critical for this activity. Moreover, we found that NAC also exerts a ribosome-independent chaperone function in vivo. Consistently, we found that a substantial fraction of NAC is non-ribosomal bound in higher eukaryotes. In sum, NAC is a potent suppressor of aggregation and proteotoxicity of mutant PolyQ-expanded proteins associated with human diseases like Huntington's disease and spinocerebellar ataxias.
Subject(s)
Amyloid beta-Peptides/genetics , Molecular Chaperones/genetics , Protein Aggregation, Pathological/genetics , Amyloid beta-Peptides/chemistry , Binding Sites/genetics , Humans , Huntington Disease/genetics , Huntington Disease/pathology , Luciferases/chemistry , Luciferases/genetics , Molecular Chaperones/chemistry , Peptides/chemistry , Peptides/genetics , Protein Binding/genetics , Protein Biosynthesis/genetics , Protein Domains/genetics , Protein Folding , Ribosomes/genetics , Spinocerebellar Ataxias/genetics , Spinocerebellar Ataxias/pathologyABSTRACT
Bacterial microcompartments (MCPs) are extremely large (100-400 nm) and diverse proteinaceous organelles that compartmentalize multistep metabolic pathways, increasing their efficiency and sequestering toxic and/or volatile intermediates. This review highlights recent studies that have expanded our understanding of the diversity, structure, function, and potential biotechnological uses of MCPs. Several new types of MCPs have been identified and characterized revealing new functions and potential new associations with human disease. Recent structural studies of MCP proteins and recombinant MCP shells have provided new insights into MCP assembly and mechanisms and raised new questions about MCP structure. We also discuss recent work on biotechnology applications that use MCP principles to develop nanobioreactors, nanocontainers, and molecular scaffolds.
Subject(s)
Bacteria , Bacterial Proteins , Bacteria/metabolism , Bacterial Proteins/metabolism , Humans , Metabolic Networks and Pathways , Organelles/metabolismABSTRACT
The energetic and geometric features enabling redox chemistry across the copper cupredoxin fold contain key components of electron transfer chains (ETC), which have been extended here by templating the cross-ß bilayer assembly of a synthetic nonapeptide, HHQALVFFA-NH2 (K16A), with copper ions. Similar to ETC cupredoxin plastocyanin, these assemblies contain copper sites with blue-shifted (λmax 573 nm) electronic transitions and strongly oxidizing reduction potentials. Electron spin echo envelope modulation and X-ray absorption spectroscopies define square planar Cu(II) sites containing a single His ligand. Restrained molecular dynamics of the cross-ß peptide bilayer architecture support metal ion coordination stabilizing the leaflet interface and indicate that the relatively high reduction potential is not simply the result of distorted coordination geometry (entasis). Cyclic voltammetry (CV) supports a charge-hopping mechanism across multiple copper centers placed 10-12 Å apart within the assembled peptide leaflet interface. This metal-templated scaffold accordingly captures the electron shuttle and cupredoxin functionality in a peptide membrane-localized electron transport chain.
ABSTRACT
OBJECTIVE: The aim of this study was to evaluate factors associated with extracutaneous involvement (ECI) in juvenile localized scleroderma (jLS). METHODS: A prospective, multicentre, 6-month observational study was performed. The data collected included disease features, global assessments, and subject symptoms. Bivariate and linear multilevel regression analyses were performed. RESULTS: A total of 86 jLS subjects (80% female, 80% Caucasian), median age of disease onset 7.7 years, were evaluated. Most had linear scleroderma or mixed morphea. Of the 86 subjects, 49 (57%) had 125 extracutaneous problems {median 2 [interquartile range (IQR) 1, 3] per subject} from nine organ systems. Most of these subjects had multiple musculoskeletal problems. ECI was associated with more extensive cutaneous involvement, higher number of symptoms, family history of autoimmunity, and ANA and RF positivity. Subjects with ECI had higher scores for physician global assessment of damage (PGA-D), and parental global assessment of disease impact, but not baseline physician global assessment of disease activity (PGA-A). Although subjects with ECI received more MTX and glucocorticoid treatment, they had a slower reduction in PGA-A scores and symptoms over time, suggesting a poorer response to treatment. In logistic regression modelling, female sex had the largest effect on parental impact scores. CONCLUSION: ECI occurred in the majority of subjects with jLS, and was associated with more medication use, longer treatment duration, higher PGA-D scores, and higher parental assessment of disease impact. Our findings suggest that jLS subjects with ECI have greater overall disease burden, both cutaneous and extracutaneous, and poorer response to treatment. More study of the treatment needs of this population is warranted.
Subject(s)
Musculoskeletal Diseases/etiology , Quality of Life , Scleroderma, Localized/diagnosis , Child , Female , Follow-Up Studies , Humans , Male , Morbidity/trends , Musculoskeletal Diseases/epidemiology , Prospective Studies , Scleroderma, Localized/complications , Scleroderma, Localized/epidemiology , Severity of Illness Index , Time Factors , United States/epidemiologyABSTRACT
Health technology assessment agencies often prefer that utilities used to calculate quality-adjusted life years in cost-utility analyses (CUAs) are derived using standardized methods, such as generic preference-based measures completed by patients in clinical trials. However, there are situations when no standardized approach is feasible or appropriate for a specific medical condition or treatment that must be represented in a CUA. When this occurs, vignette-based methods are often used to estimate utilities. A vignette (sometimes called a "scenario," "health state description," "health state vignette," or "health state") is a description of a health state that is valued in a preference elicitation task to obtain a utility estimate. This method is sometimes the only feasible way to estimate utilities representing a concept that is important for a CUA. Consequently, vignette-based studies continue to be conducted and published, with the resulting utilities used in economic models to inform decision making about healthcare resource allocation. Despite the potential impact of vignette-based utilities on medical decision making, there is no published guidance or review of this methodology. This article provides recommendations for researchers, health technology assessment reviewers, and policymakers who may be deciding whether to use vignette-based methods, designing a vignette study, using vignette-based utilities in a CUA, or evaluating a CUA that includes vignette-based utilities. Recommendations are provided on: (A) when to use vignette-based utilities, (B) methods for developing vignettes, (C) valuing vignettes, (D) use of vignette-based utilities in models, and (E) limitations of vignette methods.
Subject(s)
Delivery of Health Care , Health Status Indicators , Health Status , Research Design , Technology Assessment, Biomedical , Cost-Benefit Analysis , Delivery of Health Care/economics , Health Care Costs , Humans , Quality-Adjusted Life Years , Technology Assessment, Biomedical/economicsABSTRACT
PURPOSE: Previous research suggests that treatment process can have an influence on patient preference and health state utilities. This study examined preferences and estimated utilities for treatment processes of two daily oral treatment regimens and two weekly injectable regimens for treatment of type 2 diabetes (T2D). METHODS: Participants with T2D in the UK reported preferences and valued four health state vignettes in time trade-off utility interviews. The vignettes had identical descriptions of T2D but differed in treatment process: (1) daily simple oral treatment (tablets without administration requirements), (2) daily oral semaglutide (with administration requirements per product label), (3) weekly dulaglutide injection, (4) weekly semaglutide injection. RESULTS: Interviews were completed by 201 participants (52.7% male; mean age = 58.7). Preferences between treatment processes varied widely. Mean utilities were 0.890 for simple oral, 0.880 for oral semaglutide, 0.878 for dulaglutide injection, and 0.859 for semaglutide injection (with higher scores indicating greater preference). All pairwise comparisons found statistically significant differences between utilities (p < 0.01), except the comparison between oral semaglutide and the dulaglutide injection (p = 0.49). CONCLUSIONS: Results suggest that routes of administration cannot be compared using only the simplest descriptions (e.g., oral versus injectable). Dose frequency and specific details of the treatment process administration had an impact on patient preference and health state utilities. The utilities estimated in this study may be useful in cost-utility models comparing these treatments for T2D. Results also suggest that it may be helpful to consider patient preferences for treatment process when selecting medications for patients in clinical settings.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Glucagon-Like Peptide-1 Receptor/therapeutic use , Hypoglycemic Agents/therapeutic use , Quality of Life/psychology , Aged , Diabetes Mellitus, Type 2/pathology , Female , Glucagon-Like Peptide-1 Receptor/agonists , Glucagon-Like Peptide-1 Receptor/metabolism , Humans , Hypoglycemic Agents/pharmacology , Male , Middle AgedABSTRACT
Bacterial microcompartments (MCPs) are widespread protein-based organelles composed of metabolic enzymes encapsulated within a protein shell. The function of MCPs is to optimize metabolic pathways by confining toxic and/or volatile pathway intermediates. A major class of MCPs known as glycyl radical MCPs has only been partially characterized. Here, we show that uropathogenic Escherichia coli CFT073 uses a glycyl radical MCP for 1,2-propanediol (1,2-PD) fermentation. Bioinformatic analyses identified a large gene cluster (named grp for glycyl radical propanediol) that encodes homologs of a glycyl radical diol dehydratase, other 1,2-PD catabolic enzymes, and MCP shell proteins. Growth studies showed that E. coli CFT073 grows on 1,2-PD under anaerobic conditions but not under aerobic conditions. All 19 grp genes were individually deleted, and 8/19 were required for 1,2-PD fermentation. Electron microscopy and genetic studies showed that a bacterial MCP is involved. Bioinformatics combined with genetic analyses support a proposed pathway of 1,2-PD degradation and suggest that enzymatic cofactors are recycled internally within the Grp MCP. A two-component system (grpP and grpQ) is shown to mediate induction of the grp locus by 1,2-PD. Tests of the E. coli Reference (ECOR) collection indicate that >10% of E. coli strains ferment 1,2-PD using a glycyl radical MCP. In contrast to other MCP systems, individual deletions of MCP shell genes (grpE, grpH, and grpI) eliminated 1,2-PD catabolism, suggesting significant functional differences with known MCPs. Overall, the studies presented here are the first comprehensive genetic analysis of a Grp-type MCP.IMPORTANCE Bacterial MCPs have a number of potential biotechnology applications and have been linked to bacterial pathogenesis, cancer, and heart disease. Glycyl radical MCPs are a large but understudied class of bacterial MCPs. Here, we show that uropathogenic E. coli CFT073 uses a glycyl radical MCP for 1,2-PD fermentation, and we conduct a comprehensive genetic analysis of the genes involved. Studies suggest significant functional differences between the glycyl radical MCP of E. coli CFT073 and better-studied MCPs. They also provide a foundation for building a deeper general understanding of glycyl radical MCPs in an organism where sophisticated genetic methods are available.
Subject(s)
Escherichia coli Proteins/genetics , Organelles/metabolism , Propylene Glycol/metabolism , Uropathogenic Escherichia coli/genetics , Uropathogenic Escherichia coli/metabolism , Escherichia coli Proteins/metabolism , Fermentation , Gene Expression Regulation, Bacterial , Metabolic Networks and Pathways , Multigene Family , Organelles/geneticsABSTRACT
AIM: When selecting treatments for type 2 diabetes (T2D), it is important to consider not only efficacy and safety, but also other treatment attributes that have an impact on patient preference. The objective of this study was to examine preference between injection devices used for two weekly GLP-1 receptor agonists. MATERIALS AND METHODS: The PREFER study was an open-label, multicentre, randomized, crossover study assessing patient preference for dulaglutide and semaglutide injection devices among injection-naïve patients receiving oral medication for type 2 diabetes. After being trained to use each device, participants performed all steps of injection preparation and administered mock injections into an injection pad. Time-to-train (TTT) for each device was assessed in a subset. RESULTS: There were 310 evaluable participants (48.4% female; mean age, 60.0 years; 78 participants in the TTT subgroup). More participants preferred the dulaglutide device than the semaglutide device (84.2% vs. 12.3%; P < 0.0001). More participants perceived the dulaglutide device to have greater ease of use (86.8% vs. 6.8%; P < 0.0001). After preparing and using the devices, more participants were willing to use the dulaglutide device (93.5%) than the semaglutide device (45.8%). Training participants to use the dulaglutide device required less time than the semaglutide device (3.38 vs. 8.14 minutes; P < 0.0001). CONCLUSIONS: Participants with type 2 diabetes preferred the dulaglutide injection device to the semaglutide injection device. If patients prefer a device, they may be more willing to use the medication, which could result in better health outcomes. Furthermore, a shorter training time for injection devices may be helpful in busy clinical practice settings.
Subject(s)
Diabetes Mellitus, Type 2 , Cross-Over Studies , Diabetes Mellitus, Type 2/drug therapy , Female , Glucagon-Like Peptides/analogs & derivatives , Humans , Hypoglycemic Agents , Immunoglobulin Fc Fragments , Male , Middle Aged , Patient Preference , Recombinant Fusion ProteinsABSTRACT
Amyloid deposits of WT apolipoprotein A-I (apoA-I), the main protein component of high-density lipoprotein, accumulate in atherosclerotic plaques where they may contribute to coronary artery disease by increasing plaque burden and instability. Using CD analysis, solid-state NMR spectroscopy, and transmission EM, we report here a surprising cooperative effect of heparin and the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG), a known inhibitor and modulator of amyloid formation, on apoA-I fibrils. We found that heparin, a proxy for glycosaminoglycan (GAG) polysaccharides that co-localize ubiquitously with amyloid in vivo, accelerates the rate of apoA-I formation from monomeric protein and associates with insoluble fibrils. Mature, insoluble apoA-I fibrils bound EGCG (KD = 30 ± 3 µm; Bmax = 40 ± 3 µm), but EGCG did not alter the kinetics of apoA-I amyloid assembly from monomer in the presence or absence of heparin. EGCG selectively increased the mobility of specific backbone and side-chain sites of apoA-I fibrils formed in the absence of heparin, but the fibrils largely retained their original morphology and remained insoluble. By contrast, fibrils formed in the presence of heparin were mobilized extensively by the addition of equimolar EGCG, and the fibrils were remodeled into soluble 20-nm-diameter oligomers with a largely α-helical structure that were nontoxic to human umbilical artery endothelial cells. These results argue for a protective effect of EGCG on apoA-I amyloid associated with atherosclerosis and suggest that EGCG-induced remodeling of amyloid may be tightly regulated by GAGs and other amyloid co-factors in vivo, depending on EGCG bioavailability.
Subject(s)
Amyloid/chemistry , Apolipoprotein A-I/chemistry , Catechin/analogs & derivatives , Heparin/chemistry , Catechin/chemistry , Humans , Magnetic Resonance Spectroscopy , Protein Structure, SecondaryABSTRACT
The amino-acid sequences of soluble, globular proteins must have hydrophobic residues to form a stable core, but excess sequence hydrophobicity can lead to loss of native state conformational specificity and aggregation. Previous studies of polar-to-hydrophobic mutations in the ß-sheet of the Arc repressor dimer showed that a single substitution at position 11 (N11L) leads to population of an alternate dimeric fold in which the ß-sheet is replaced by helix. Two additional hydrophobic mutations at positions 9 and 13 (Q9V and R13V) lead to population of a differently folded octamer along with both dimeric folds. Here we conduct a comprehensive study of the sequence determinants of this progressive loss of fold specificity. We find that the alternate dimer-fold specifically results from the N11L substitution and is not promoted by other hydrophobic substitutions in the ß-sheet. We also find that three highly hydrophobic substitutions at positions 9, 11, and 13 are necessary and sufficient for oligomer formation, but the oligomer size depends on the identity of the hydrophobic residue in question. The hydrophobic substitutions increase thermal stability, illustrating how increased hydrophobicity can increase folding stability even as it degrades conformational specificity. The oligomeric variants are predicted to be aggregation-prone but may be hindered from doing so by proline residues that flank the ß-sheet region. Loss of conformational specificity due to increased hydrophobicity can manifest itself at any level of structure, depending upon the specific mutations and the context in which they occur.
Subject(s)
Hydrophobic and Hydrophilic Interactions , Mutation , Protein Folding , Protein Structure, Secondary , Repressor Proteins/chemistry , Repressor Proteins/genetics , Amino Acid Substitution , Models, MolecularABSTRACT
BACKGROUND: Congenital morphea is a form of localized scleroderma that presents at birth. There is limited information on its presentation and progression. METHODS: Patients with congenital morphea were identified from five pediatric dermatology and rheumatology tertiary care centers in Canada, the United States, and Italy from 2001 to 2016. Cases from the literature were identified by searching Ovid (EMBASE and MEDLINE) from inception to June 30, 2017. Disease characteristics and prevalence of extracutaneous involvement were analyzed. RESULTS: Thirteen patients were identified from the five centers, and 13 cases were described in the literature, representing 25 patients, with one duplication. Fourteen patients (56%) were female. Median age at diagnosis was 2.9 years (interquartile range 1.2-5.1 years). Linear morphea, including en coup de sabre and Parry-Romberg syndrome, was the most common subtype observed (n = 19, 76%), followed by circumscribed (n = 5, 20%), generalized (n = 2, 8%), and mixed (n = 2, 8%). The face (n = 14, 56%), scalp (n = 8, 32%), and trunk (n = 6, 24%) were the most common locations affected. Most lesions were active at diagnosis (n = 19, 76%), but all patients with follow-up later became inactive. Extracutaneous involvement was seen in 12 (48%) patients, all of whom had linear morphea. Musculoskeletal sequelae were seen in those with linear morphea of the extremities (4/5, 80%), and neurologic involvement was seen in those with linear morphea of the head (8/13, 62%). CONCLUSION: Congenital morphea is associated with extracutaneous manifestations and delayed diagnosis. More research is needed to determine whether early recognition, monitoring, and treatment can alter the disease course.
Subject(s)
Scleroderma, Localized/diagnosis , Canada/epidemiology , Child, Preschool , Cohort Studies , Disease Progression , Female , Humans , Infant , Italy/epidemiology , Male , Prevalence , Retrospective Studies , Scleroderma, Localized/congenital , Scleroderma, Localized/epidemiology , United States/epidemiologyABSTRACT
BACKGROUND: Glucose monitoring is important for patients with diabetes treated with insulin. Conventional glucose monitoring requires a blood sample, typically obtained by pricking the finger. A new sensor-based system called "flash glucose monitoring" monitors glucose levels with a sensor worn on the arm, without requiring blood samples. OBJECTIVES: To estimate the utility difference between these two glucose monitoring approaches for use in cost-utility models. METHODS: In time trade-off interviews, general population participants in the United Kingdom (London and Edinburgh) valued health states that were drafted and refined on the basis of literature, clinician input, and a pilot study. The health states had identical descriptions of diabetes and insulin treatment, differing only in glucose monitoring approach. RESULTS: A total of 209 participants completed the interviews (51.7% women; mean age = 42.1 years). Mean utilities were 0.851 ± 0.140 for conventional monitoring and 0.882 ± 0.121 for flash monitoring (significant difference between the mean utilities; t = 8.3; P < 0.0001). Of the 209 participants, 78 (37.3%) had a higher utility for flash monitoring, 2 (1.0%) had a higher utility for conventional monitoring, and 129 (61.7%) had the same utility for both health states. CONCLUSIONS: The flash glucose monitoring system was associated with a significantly greater utility than the conventional monitoring system. This difference may be useful in cost-utility models comparing the value of glucose monitoring devices for patients with diabetes. This study adds to the literature on treatment process utilities, suggesting that time trade-off methods may be used to quantify preferences among medical devices.
Subject(s)
Blood Glucose Self-Monitoring/methods , Patient Preference , Adult , Blood Glucose , Blood Glucose Self-Monitoring/economics , Cost-Benefit Analysis , Diabetes Mellitus , Female , Humans , Interviews as Topic , Male , Middle Aged , Pilot Projects , Quality of Life , United Kingdom , Young AdultABSTRACT
PURPOSE: Despite benefits of antiretroviral therapies (ART), people with HIV infection have increased risk of cardiovascular disease, kidney disease, and low bone mineral density. Some ARTs increase risk of these events. The purpose of this study was to examine patients' perspectives of these risks and estimate health state utilities associated with these risks for use in cost-utility models. METHODS: Qualitative thematic analysis was conducted to examine messages posted to the POZ/AIDSmeds Internet community forums, focusing on bone, kidney, and cardiovascular side effects and risks of HIV/AIDS medications. Then, health state vignettes were drafted based on this qualitative analysis, literature review, and clinician interviews. The health states (representing HIV, plus treatment-related risks) were valued in time trade-off interviews with general population participants in the UK. RESULTS: Qualitative analysis of the Internet forums documented patient concerns about ART risks, as well as treatment decisions made because of these risks. A total of 208 participants completed utility interviews (51.4% female; mean age 44.6 years). The mean utility of the HIV health state (virologically suppressed, treated with ART) was 0.86. Adding a description of risk resulted in statistically significant disutility (i.e., utility decreases): renal risk (disutility = -0.02), bone risk (-0.03), and myocardial infarction risk (-0.05). CONCLUSIONS: Patient concerns and treatment decisions were documented via qualitative analysis of Internet forum discussions, and the impact of these concerns was quantified in terms of health state utilities. The resulting disutilities may be useful for differentiating among ARTs in economic modeling of treatment for patients with HIV.
Subject(s)
Anti-Retroviral Agents/therapeutic use , HIV Infections/drug therapy , Sickness Impact Profile , Social Media/statistics & numerical data , Adult , Female , Humans , Male , Pilot Projects , RiskABSTRACT
BACKGROUND: Glucagon-like peptide-1 (GLP-1) receptor agonists are often recommended as part of combination therapy for type 2 diabetes when oral medication does not result in sufficient glycemic control. Several GLP-1 receptor agonists are available as weekly injections. These medications vary in their injection delivery systems, and these differences could impact quality of life and treatment preference. The purpose of this study was to estimate utilities associated with attributes of injection delivery systems for weekly GLP-1 therapies. METHODS: Participants with type 2 diabetes in the UK valued health states in time trade-off interviews. The health states (drafted based on literature, device instructions for use, and clinician interviews) had identical descriptions of type 2 diabetes, but differed in description of the treatment process. One health state described oral treatment, while six others described oral treatment plus a weekly injection. The injection health states varied in three aspects of the treatment administration process: requirements for reconstituting the medication (i.e., mixing the medication prior to the injection), waiting during medication preparation, and needle handling. Every participant valued all seven health states. RESULTS: A total of 209 participants completed interviews (57.4% male; mean age = 60.4y). The mean utility of the oral treatment health state was 0.89. All injection health states had significantly (p < 0.01) lower utilities ranging from 0.86 to 0.88. Differences among health state utilities suggest that each administration requirement had a small but measureable disutility: -0.004 (reconstitution), -0.004 (needle handling), -0.010 (reconstitution, needle handling), and -0.020 (reconstitution, waiting, needle handling). CONCLUSIONS: Findings suggest it is feasible to use the TTO method to quantify preferences among injection treatment processes. It may be useful to incorporate these utility differences into cost-utility models comparing weekly injectable treatments for patients with type 2 diabetes.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Glucagon-Like Peptide-1 Receptor/agonists , Hypoglycemic Agents/administration & dosage , Injections, Subcutaneous/instrumentation , Adult , Aged , Feasibility Studies , Female , Health Status , Humans , Injections, Subcutaneous/methods , Male , Middle Aged , Quality of Life , Time Factors , United KingdomABSTRACT
The amyloid plaques associated with Alzheimer's disease (AD) comprise fibrillar amyloid-ß (Aß) peptides as well as non-protein factors including glycosaminoglycan (GAG) polysaccharides. GAGs affect the kinetics and pathway of Aß self-assembly and can impede fibril clearance; thus, they may be accessory molecules in AD. Here we report the first high-resolution details of GAG-Aß fibril interactions from the perspective of the saccharide. Binding analysis indicated that the GAG proxy heparin has a remarkably high affinity for Aß fibrils with 3-fold cross-sectional symmetry (3Q). Chemical synthesis of a uniformly (13)C-labeled octasaccharide heparin analogue enabled magic-angle spinning solid-state NMR of the GAG bound to 3Q fibrils, and measurements of dynamics revealed a tight complex in which all saccharide residues are restrained without undergoing substantial conformational changes. Intramolecular (13)C-(15)N dipolar dephasing is consistent with close (<5 Å) contact between GAG anomeric position(s) and one or more histidine residues in the fibrils. These data provide a detailed model for the interaction between 3Q-seeded Aß40 fibrils and a major non-protein component of AD plaques, and they reveal that GAG-amyloid interactions display a range of affinities that critically depend on the precise details of the fibril architecture.
Subject(s)
Amyloid beta-Peptides/chemistry , Amyloid beta-Peptides/metabolism , Glycosaminoglycans/metabolism , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Models, Molecular , Nuclear Magnetic Resonance, Biomolecular , Protein Structure, SecondaryABSTRACT
BACKGROUND: The EQ-5D is frequently used to derive utilities for patients with type 2 diabetes (T2D). Despite widely available quantitative psychometric data on the EQ-5D, little is known about content validity in this population. Thus, the purpose of this qualitative study was to examine content validity of the EQ-5D in patients with T2D. METHODS: Patients with T2D in the UK completed concept elicitation interviews, followed by administration of the EQ-5D-5L and cognitive interviewing focused on the instrument's relevance, clarity, and comprehensiveness. RESULTS: A total of 25 participants completed interviews (52.0 % male; mean age = 53.5 years). Approximately half (52 %) reported that the EQ-5D-5L was relevant to their experience with T2D. When asked if each individual item was relevant to their experience with T2D, responses varied widely (24.0 % said the self-care item was relevant; 68.0 % said the anxiety/depression item was relevant). Participants frequently said items were not relevant to themselves, but could be relevant to patients with more severe diabetes. Most participants (92.0 %) reported that T2D and/or its treatment/monitoring requirements had an impact on their quality of life that was not captured by the EQ-5D-5L. Common missing concepts included food awareness/restriction (n = 13, 52.0 %); activities (n = 11, 44.0 %); emotional functioning other than depression/anxiety (n = 8, 32.0 %); and social/relationship functioning (n = 8, 32.0 %). CONCLUSIONS: The results highlight strengths and potential limitations of the EQ-5D-5L, including missing content that could be important for some patients with T2D. Suggestions for addressing limitations are provided.
Subject(s)
Diabetes Mellitus, Type 2/psychology , Psychometrics/instrumentation , Quality of Life/psychology , Adult , Female , Humans , Male , Middle Aged , Qualitative Research , Reproducibility of Results , Surveys and Questionnaires , United KingdomABSTRACT
BACKGROUND: Cost-utility models are frequently used to compare treatments intended to prevent or delay the onset of cardiovascular events. Most published utilities represent post-event health states without incorporating the disutility of the event or reporting the time between the event and utility assessment. Therefore, this study estimated health state utilities representing cardiovascular conditions while distinguishing between acute impact including the cardiovascular event and the chronic post-event impact. METHODS: Health states were drafted and refined based on literature review, clinician interviews, and a pilot study. Three cardiovascular conditions were described: stroke, acute coronary syndrome (ACS), and heart failure. One-year acute health states represented the event and its immediate impact, and post-event health states represented chronic impact. UK general population respondents valued the health states in time trade-off tasks with time horizons of one year for acute states and ten years for chronic states. RESULTS: A total of 200 participants completed interviews (55% female; mean age = 46.6 y). Among acute health states, stroke had the lowest utility (0.33), followed by heart failure (0.60) and ACS (0.67). Utility scores for chronic health states followed the same pattern: stroke (0.52), heart failure (0.57), and ACS (0.82). For stroke and ACS, acute utilities were significantly lower than chronic post-event utilities (difference = 0.20 and 0.15, respectively; both p < 0.0001). CONCLUSIONS: Results add to previously published utilities for cardiovascular events by distinguishing between chronic post-event health states and acute health states that include the event and its immediate impact. Findings suggest that acute versus chronic impact should be considered when selecting scores for use in cost-utility models. Thus, the current utilities provide a unique option that may be used to represent the acute and chronic impact of cardiovascular conditions in economic models comparing treatments that may delay or prevent the onset of cardiovascular events.
Subject(s)
Acute Coronary Syndrome , Health Status , Heart Failure , Quality of Life , Stroke , Acute Coronary Syndrome/economics , Adult , Aged , Chronic Disease , Female , Heart Failure/economics , Humans , Interviews as Topic , London , Male , Middle Aged , Models, Economic , Pilot Projects , Qualitative Research , Scotland , Stroke/economics , Young AdultABSTRACT
AIMS: Health state utilities associated with weight change are needed for cost-utility analyses (CUAs) examining the value of treatments for type 2 diabetes and obesity. Previous studies have estimated the utility benefits associated with various amounts of weight reduction in the US and Europe, but preferences for weight change in Asian cultures may differ from these published values. The purpose of this study was to estimate utilities associated with reductions in body weight based on preferences of individuals with type 2 diabetes and obesity in Japan. METHODS: Health state vignettes represented type 2 diabetes with respondents' own current weight and weight reductions of 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, and 20%. Utilities were elicited in time trade-off interviews with a sample of respondents in Japan with type 2 diabetes and body mass index (BMI) ≥25 kg/m2 (the cutoff for obesity in Japan). RESULTS: Analyses were conducted with data from 138 respondents (84.8% male; mean age = 58.0 years; mean BMI = 29.4 kg/m2) from all eight regions of Japan. Utility gains gradually increased with rising percentage of weight reductions ranging from 2.5% to 15%. Weight reductions of 2.5% to 15% resulted in utility increases of 0.013 to 0.048. The health state representing a 20% weight reduction yielded a wide range of preferences (mean utility increase of 0.044). Equations are recommended for estimating utility change based on any percentage of weight reduction (up to 20%) in Japanese people with type 2 diabetes and obesity. LIMITATIONS: This study was conducted in a sample with limited representation of patients with BMI >35 kg/m2 (n = 13) and relatively few women (n = 21). CONCLUSION: Results may be used to provide inputs for CUAs examining the value of treatments that are associated with weight loss in patients with type 2 diabetes and obesity in Japan.
Subject(s)
Diabetes Mellitus, Type 2 , East Asian People , Female , Humans , Male , Middle Aged , Diabetes Mellitus, Type 2/therapy , Diabetes Mellitus, Type 2/complications , Japan , Obesity/complications , Weight LossABSTRACT
INTRODUCTION: Acid sphingomyelinase deficiency (ASMD) type B is a rare genetic disorder leading to enlargement of the spleen and liver, pulmonary dysfunction, and other symptoms. Cost-utility analyses are often conducted to quantify the value of new treatments, and these analyses require health state utilities. Therefore, the purpose of this study was to estimate utilities associated with varying levels of severity of adult and pediatric ASMD type B. METHODS: Seven adult and seven child health state vignettes describing ASMD were developed based on published literature, clinical trial results, and interviews with clinicians, patients with ASMD, and parents of children with ASMD. The health states were valued in time trade-off interviews with adult general population respondents in the UK. RESULTS: Interviews were completed with 202 participants (50.0% female; mean age = 41.3 years). The health state representing ASMD without impairment had the highest mean utility for both the adult and child health states (0.92/0.94), and severe ASMD had the lowest mean utility (0.33/0.45). Every child health state had a significantly greater utility than the corresponding adult health state. Differences between adult/child paired states ranged from 0.02 to 0.13. Subgroup analyses explored the impact of parenting status on valuation of child health states. DISCUSSION: Greater severity of ASMD was associated with lower mean utility. Results have implications for valuation of pediatric health states. The resulting utilities may be useful in cost-utility modeling estimating the value of treatment for ASMD.