Symptom-based stratification of patients with primary Sjögren's syndrome: multi-dimensional characterisation of international observational cohorts and reanalyses of randomised clinical trials

Background Heterogeneity is a major obstacle to developing effective treatments for patients with primary Sjögren's syndrome. We aimed to develop a robust method for stratification, exploiting heterogeneity in patient-reported symptoms, and to relate these differences to pathobiology and therapeutic response. Methods We did hierarchical cluster analysis using five common symptoms associated with primary Sjögren's syndrome (pain, fatigue, dryness, anxiety, and depression), followed by multinomial logistic regression to identify subgroups in the UK Primary Sjögren's Syndrome Registry (UKPSSR). We assessed clinical and biological differences between these subgroups, including transcriptional differences in peripheral blood. Patients from two independent validation cohorts in Norway and France were used to confirm patient stratification. Data from two phase 3 clinical trials were similarly stratified to assess the differences between subgroups in treatment response to hydroxychloroquine and rituximab. Findings In the UKPSSR cohort (n=608), we identified four subgroups: Low symptom burden (LSB), high symptom burden (HSB), dryness dominant with fatigue (DDF), and pain dominant with fatigue (PDF). Significant differences in peripheral blood lymphocyte counts, anti-SSA and anti-SSB antibody positivity, as well as serum IgG, κ-free light chain, β2-microglobulin, and CXCL13 concentrations were observed between these subgroups, along with differentially expressed transcriptomic modules in peripheral blood. Similar findings were observed in the independent validation cohorts (n=396). Reanalysis of trial data stratifying patients into these subgroups suggested a treatment effect with hydroxychloroquine in the HSB subgroup and with rituximab in the DDF subgroup compared with placebo. Interpretation Stratification on the basis of patient-reported symptoms of patients with primary Sjögren's syndrome revealed distinct pathobiological endotypes with distinct responses to immunomodulatory treatments. Our data have important implications for clinical management, trial design, and therapeutic development. Similar stratification approaches might be useful for patients with other chronic immune-mediated diseases. Funding UK Medical Research Council, British Sjogren's Syndrome Association, French Ministry of Health, Arthritis Research UK, Foundation for Research in Rheumatology

Value of ultrasonography as a marker of early response to abatacept in patients with rheumatoid arthritis and an inadequate response to methotrexate: results from the APPRAISE study

Objectives: To study the responsiveness of a combined power Doppler and greyscale ultrasound (PDUS) score for assessing synovitis in biologic-naïve patients with rheumatoid arthritis (RA) starting abatacept plus methotrexate (MTX). Methods: In this open-label, multicentre, single-arm study, patients with RA (MTX inadequate responders) received intravenous abatacept (∼10 mg/kg) plus MTX for 24 weeks. A composite PDUS synovitis score, developed by the Outcome Measures in Rheumatology–European League Against Rheumatism (OMERACT–EULAR)-Ultrasound Task Force, was used to evaluate individual joints. The maximal score of each joint was added into a Global OMERACT–EULAR Synovitis Score (GLOESS) for bilateral metacarpophalangeal joints (MCPs) 2–5 (primary objective). The value of GLOESS containing other joint sets was explored, along with clinical efficacy. Results: Eighty-nine patients completed the 24-week treatment period. The earliest PDUS sign of improvement in synovitis was at week 1 (mean change in GLOESS (MCPs 2–5): −0.7 (95% CIs −1.2 to −0.1)), with continuous improvement to week 24. Early improvement was observed in the component scores (power Doppler signal at week 1, synovial hyperplasia at week 2, joint effusion at week 4). Comparable changes were observed for 22 paired joints and minimal joint subsets. Mean Disease Activity Score 28 (C reactive protein) was significantly reduced from weeks 1 to 24, reaching clinical meaningful improvement (change ≥1.2) at week 8. Conclusions: In this first international prospective study, the composite PDUS score is responsive to abatacept. GLOESS demonstrated the rapid onset of action of abatacept, regardless of the number of joints examined. Ultrasound is an objective tool to monitor patients with RA under treatment. Trial registration number: NCT00767325

Impact de la TEP/TDM au 18FDG sur la prise en charge des patients atteints de carcinome de Merkel : étude rétrospective monocentrique de 66 examens

Les carcinomes de Merkel (CCM) sont des tumeurs endocrines cutanées rares et agressives, dont la prise en charge optimale n'est pas clairement définie. L'objectif de l'étude a été d'évaluer l impact de la TEP/TDM au 18FDG (TEP-FDG) sur le staging et la prise en charge des patients présentant un CCM. Méthodes : 23 patients avec diagnostic histologique de CCM explorés entre 2006 et 2012 par TEP-FDG ont été inclus rétrospectivement. La découverte de nouvelles lésions, la modification du stade tumoral et des modalités de prise en charge après réalisation de l'examen ont été évaluées. Les résultats de TEP-FDG ont été comparés aux données histologiques, cliniques et d imagerie disponibles pour chaque patient. Résultats : 66 examens ont été réalisés en bilan d extension initial (n=18), suivi évolutif (n=34) ou évaluation de la réponse thérapeutique à la chimiothérapie (n=14). Les sensibilité, spécificité, valeurs prédictives positive et négative de la TEP-FDG étaient respectivement de 97%, 89%, 94% et 94%. Des lésions non décelées cliniquement et/ou par imagerie conventionnelle ont été détectées sur 44% des 52 examens réalisés en bilan initial et suivi évolutif (respectivement 50% et 41%). La TEP-FDG a entraîné une modification de stade tumoral chez 39% des patients en bilan initial et une modification d'attitude thérapeutique chez un tiers des patients (33% des patients en bilan initial, 32% en suivi évolutif et 36% en évaluation thérapeutique). Enfin, la TEP-FDG a détecté fortuitement 4 seconds cancers confirmés histologiquement. Conclusion: Cette étude rétrospective mono-centrique confirme l impact important de la TEP-FDG sur la prise en charge des patients porteurs de CCM.Background: Merkel cell carcinomas (MCC) are rare and aggressive neuroendocrine skin tumors for which an optimal treatment procedure remains to be defined. These extremely lymphophilic tumors are frequently responsible for lymph node recurrence and metastatic disease. The objective of this study was to evaluate the impact of 18F-FDG PET/CT on the staging and treatment of MCC patients. Methods: 23 patients with a histologic diagnosis of MCC explored by 18F-FDG PET/CT between 2004 and 2012 were retrospectively included in the study. The detection of new lesions, the change in tumor staging and treatment were evaluated. For each patient, the PET/CT results were compared to histological, clinical and imaging data. Results: 66 PET/CT scans were performed at initial presentation (n=18), subsequent monitoring (n=34) or in evaluation of chemotherapy response (n=14). The sensitivity, specificity, positive and negative predictive values of the PET were 97%, 89%, 94% and 94% respectively. Two false-positive results (lymphadenitis) and one false-negative result (regional metastatic lymph nodes) were also accounted for. Lesions not detected clinically or by conventional imaging techniques were found in 44% of the 52 PET/CT performed at initial presentation and subsequent monitoring, with respectively 50% and 41% of scans identifying new lesions. At initial presentation, PET/CT led to a change in tumor staging in 39% of patients. Patient management was modified by PET/CT results in one third of patients (33% of patients at initial presentation, 32% in subsequent monitoring, and 36% in evaluation of chemotherapy response). Moreover, PET/CT incidentally detected 4 additional histologically-confirmed cancers. Conclusion: This retrospective study confirms the important impact of 18F-FDG PET/CT in the management of MCC patients.ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

Impact de la TEP/TDM au 18FDG sur la prise en charge des patients atteints de carcinome de Merkel : étude rétrospective monocentrique de 66 examens

Les carcinomes de Merkel (CCM) sont des tumeurs endocrines cutanées rares et agressives, dont la prise en charge optimale n'est pas clairement définie. L'objectif de l'étude a été d'évaluer l impact de la TEP/TDM au 18FDG (TEP-FDG) sur le staging et la prise en charge des patients présentant un CCM. Méthodes : 23 patients avec diagnostic histologique de CCM explorés entre 2006 et 2012 par TEP-FDG ont été inclus rétrospectivement. La découverte de nouvelles lésions, la modification du stade tumoral et des modalités de prise en charge après réalisation de l'examen ont été évaluées. Les résultats de TEP-FDG ont été comparés aux données histologiques, cliniques et d imagerie disponibles pour chaque patient. Résultats : 66 examens ont été réalisés en bilan d extension initial (n=18), suivi évolutif (n=34) ou évaluation de la réponse thérapeutique à la chimiothérapie (n=14). Les sensibilité, spécificité, valeurs prédictives positive et négative de la TEP-FDG étaient respectivement de 97%, 89%, 94% et 94%. Des lésions non décelées cliniquement et/ou par imagerie conventionnelle ont été détectées sur 44% des 52 examens réalisés en bilan initial et suivi évolutif (respectivement 50% et 41%). La TEP-FDG a entraîné une modification de stade tumoral chez 39% des patients en bilan initial et une modification d'attitude thérapeutique chez un tiers des patients (33% des patients en bilan initial, 32% en suivi évolutif et 36% en évaluation thérapeutique). Enfin, la TEP-FDG a détecté fortuitement 4 seconds cancers confirmés histologiquement. Conclusion: Cette étude rétrospective mono-centrique confirme l impact important de la TEP-FDG sur la prise en charge des patients porteurs de CCM.Background: Merkel cell carcinomas (MCC) are rare and aggressive neuroendocrine skin tumors for which an optimal treatment procedure remains to be defined. These extremely lymphophilic tumors are frequently responsible for lymph node recurrence and metastatic disease. The objective of this study was to evaluate the impact of 18F-FDG PET/CT on the staging and treatment of MCC patients. Methods: 23 patients with a histologic diagnosis of MCC explored by 18F-FDG PET/CT between 2004 and 2012 were retrospectively included in the study. The detection of new lesions, the change in tumor staging and treatment were evaluated. For each patient, the PET/CT results were compared to histological, clinical and imaging data. Results: 66 PET/CT scans were performed at initial presentation (n=18), subsequent monitoring (n=34) or in evaluation of chemotherapy response (n=14). The sensitivity, specificity, positive and negative predictive values of the PET were 97%, 89%, 94% and 94% respectively. Two false-positive results (lymphadenitis) and one false-negative result (regional metastatic lymph nodes) were also accounted for. Lesions not detected clinically or by conventional imaging techniques were found in 44% of the 52 PET/CT performed at initial presentation and subsequent monitoring, with respectively 50% and 41% of scans identifying new lesions. At initial presentation, PET/CT led to a change in tumor staging in 39% of patients. Patient management was modified by PET/CT results in one third of patients (33% of patients at initial presentation, 32% in subsequent monitoring, and 36% in evaluation of chemotherapy response). Moreover, PET/CT incidentally detected 4 additional histologically-confirmed cancers. Conclusion: This retrospective study confirms the important impact of 18F-FDG PET/CT in the management of MCC patients.ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

Osmotic Compression of Anisotropic Proteins: Interaction Properties and Associated Structures in Wheat Gliadin Dispersions

In this Article, we investigated the interaction properties of wheat gliadins, properties-that are at the basis of:their functionality in wheat grain and in food matrixes: We established the equation of state of our isolate by osmotic compression and characterized the concentration-induced structural transitions, from the secondary structure of proteins to the rheological properties. We evidenced three thermodynamical regimes corresponding to several structuring regimes. First, for Phi 0.16, FT-IR spectra show that proteins are strongly interacting via intermolecular interactions. A correlation peak develops in SAXS, revealing a global order in the dispersion. Interestingly, the osmotic pressure applied to extract the solvent is higher than expected from a hard-sphere-like protein and we highlighted a liquid-like state at very high concentration (>450 g L-1) which:is in contrast with most proteins that form gel or glass at such concentration. In the discussion, we questioned the existence of supramolecular assemblies and the role of the solvation that would lead to this specific behavior

Phase behaviour of a wheat protein isolate

We investigated the liquid-liquid phase separation of wheat storage proteins with molecular weight (MW) ranging from 25 kg mol(-1) to 300 kg mol(-1). We characterized the onset of the phase separation upon a temperature decrease by turbidity. The protein compositions at equilibrium after temperature quenches were additionally determined by size-exclusion-high performance liquid chromatography. We found that wheat proteins can be classified into two classes according to their phase behaviour. The partition of the proteins between the two phases depends on their MW above a critical size of 45 kg mol(-1). For those high MW proteins, we observed that the behaviour is similar to the one of neutral, linear polymers. Their partition and critical parameters are well described by Flory-Huggins theory. Proteins below 45 kg mol(-1), namely alpha-, beta- and gamma-gliadins, have similar interaction potentials under the physicochemical conditions tested. Their phase diagrams, characterized by a low value of critical volume fraction, are characteristic of long-range interactions. Wheat protein behaviour can resultantly be rationalized in a much simpler way than expected from their complex composition

Rubisco: A promising plant protein to enrich wheat-based food without impairing dough viscoelasticity and protein polymerisation

International audienceRubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), a leaf protein, has an interesting amino acid profile and promising functional properties. Incorporated in wheat-based products, it would increase their protein content and improve their essential amino acid profile, particularly lysine. The impact of rubisco enrichment on wheat dough mechanical properties and protein-protein interactions was investigated using Dynamic Mechanical Thermal Analysis and Size-Exclusion chromatography, respectively. Experiments were also performed on gluten and pea protein enriched doughs as a comparison. Wheat doughs with increasing concentrations of rubisco, gluten or pea proteins (from 0 to 33% of total proteins) were prepared using a 2 g-mixograph at constant hydration. In contrast to pea proteins and gluten, rubisco does not reduce dough stiffening during heating, probably due to its own reactivity to temperature and to low competition with starch for water. Detailed analysis of protein interactions showed that rubisco is part of the gluten network formed during dough mixing through the establishment of weak and disulphide bonds. In addition, rubisco subunits form new covalent bonds during the heat treatment thereby increasing the concentration of SDS insoluble high molecular weight aggregates. These results suggest that rubisco actively participates in the formation of the dough protein network. The colocation of gluten and rubisco proteins on micrographs supports the hypothesis that they form a co-protein network

Dynamics of liquid-liquid phase separation of wheat gliadins

Abstract During wheat seeds development, storage proteins are synthetized and subsequently form dense protein phases, also called Protein Bodies (PBs). The mechanisms of PBs formation and the supramolecular assembly of storage proteins in PBs remain unclear. In particular, there is an apparent contradiction between the low solubility in water of storage proteins and their high local dynamics in dense PBs. Here, we probe the interplay between short-range attraction and long-range repulsion of a wheat gliadin isolate by investigating the dynamics of liquid-liquid phase separation after temperature quench. We do so using time-resolved small angle light scattering, phase contrast microscopy and rheology. We show that gliadins undergo liquid-liquid phase separation through Nucleation and Growth or Spinodal Decomposition depending on the quench depth. They assemble into dense phases but remain in a liquid-like state over an extended range of temperatures and concentrations. The analysis of phase separation kinetics reveals that the attraction strength of gliadins is in the same order of magnitude as other proteins. We discuss the respective role of competing interactions, protein intrinsic disorder, hydration and polydispersity in promoting local dynamics and providing this liquid-like behavior despite attractive forces

Unravelling the contrasting phase behavior of wheat storage proteins: how to store storage proteins?

Unravelling the contrasting phase behavior of wheat storage proteins: how to store storage proteins?. 62nd Annual Meeting of the Biophysical-Societ