EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2016 update.

Recent insights in rheumatoid arthritis (RA) necessitated updating the European League Against Rheumatism (EULAR) RA management recommendations. A large international Task Force based decisions on evidence from 3 systematic literature reviews, developing 4 overarching principles and 12 recommendations (vs 3 and 14, respectively, in 2013). The recommendations address conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs) (methotrexate (MTX), leflunomide, sulfasalazine); glucocorticoids (GC); biological (b) DMARDs (tumour necrosis factor (TNF)-inhibitors (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab), abatacept, rituximab, tocilizumab, clazakizumab, sarilumab and sirukumab and biosimilar (bs) DMARDs) and targeted synthetic (ts) DMARDs (Janus kinase (Jak) inhibitors tofacitinib, baricitinib). Monotherapy, combination therapy, treatment strategies (treat-to-target) and the targets of sustained clinical remission (as defined by the American College of Rheumatology-(ACR)-EULAR Boolean or index criteria) or low disease activity are discussed. Cost aspects were taken into consideration. As first strategy, the Task Force recommends MTX (rapid escalation to 25 mg/week) plus short-term GC, aiming at >50% improvement within 3 and target attainment within 6 months. If this fails stratification is recommended. Without unfavourable prognostic markers, switching to-or adding-another csDMARDs (plus short-term GC) is suggested. In the presence of unfavourable prognostic markers (autoantibodies, high disease activity, early erosions, failure of 2 csDMARDs), any bDMARD (current practice) or Jak-inhibitor should be added to the csDMARD. If this fails, any other bDMARD or tsDMARD is recommended. If a patient is in sustained remission, bDMARDs can be tapered. For each recommendation, levels of evidence and Task Force agreement are provided, both mostly very high. These recommendations intend informing rheumatologists, patients, national rheumatology societies, hospital officials, social security agencies and regulators about EULAR's most recent consensus on the management of RA, aimed at attaining best outcomes with current therapies.

Perceptions of risk and predictive testing held by the first-degree relatives of patients with rheumatoid arthritis in England, Austria and Germany: a qualitative study.

OBJECTIVES: The family members of patients with rheumatoid arthritis (RA) are at increased risk of developing RA and are potential candidates for predictive testing. This study explored the perceptions of first-degree relatives of people with RA about being at risk of RA and engaging in predictive testing. METHODS: 34 first-degree relatives (siblings and offspring) of patients with RA from the UK, Germany and Austria participated in semistructured interviews about their perceptions of RA risk and the prospect of predictive testing. Interviews were audio-recorded, transcribed verbatim and analysed using thematic analysis. RESULTS: First-degree relatives were aware of their susceptibility to RA, but were unsure of the extent of their risk. When considering their future risk, some relatives were concerned about the potential impact that RA would have on their lives. Relatives were concerned that knowing their actual risk would increase their anxiety and would affect decisions about their future. Also, relatives were concerned about the levels of uncertainty associated with predictive testing. Those in favour of knowing their future risk felt that they would need additional support to understand the risk information and cope with the emotional impact of this information. CONCLUSIONS: Identifying individuals at risk of RA may allow targeted interventions to reduce the risk and consequence of future disease; however, relatives have concerns about predictive testing and risk information. The development of strategies to quantify and communicate risk needs to take these views into account and incorporate approaches to mitigate concerns and minimise the psychological impact of risk information.

Tissue stroma as a regulator of leukocyte recruitment in inflammation.

The stromal milieu (cellular and matrix components) helps establish tissue "address-codes" that direct leukocyte behavior in inflamed tissue. Coordinated interactions among the stroma, leukocytes, and ECs dictate which leukocytes are recruited, whether they are retained within the inflamed site, and how long they survive. Herein, we discuss how the stromal milieu influences the leukocyte recruitment cascade. Moreover, we explore how corruption of the stromal phenotype in chronic inflammatory diseases contributes to undesired, continuous recruitment of leukocytes. Emerging complex, multicellular, multilayered (co-)culture models are now addressing the molecular circuitry involved in regulating stromal organization during inflammation. Understanding context-specific changes in pro- or anti-inflammatory agents derived from the stroma, such as IL-6 (and its cofactors), is important for the generation of therapeutic strategies that restore the balance between recruitment and clearance of the inflammatory infiltrate in chronic disease.

Modulation of functional responses of endothelial cells linked to angiogenesis and inflammation by shear stress: differential effects of the mechanotransducer CD31.

We investigated the roles of the "mechanotransducer" CD31 in the effects of shear stress on endothelial gene expression and functional responses relevant to angiogenesis and inflammation. Human or murine endothelial cells (hEC or mEC) were exposed to different levels of shear stress, while expression of CD31 was modified using siRNA in the hEC, or mEC from CD31(-/-) mice. Quantitation of expression of genes linked to inflammation or angiogenesis showed several were sensitive to shear. In a "wound" assay, exposure of endothelial cells (EC) to shear stress tended to align migration with the direction of flow and decrease the rate of closure compared to static cultures. When EC were cultured on filters, shear stress promoted migration away from the luminal surface. EC conditioned by shear stress recruited fewer flowing neutrophils, and showed reduced up-regulation of E-selectin after stimulation with tumor necrosis factor-α (TNF). Use of siRNA against CD31 in the hEC, or testing of mEC from mice lacking CD31, indicated that expression of CD31 was not required for the shear-induced modification of wound closure. However, shear modulation of response to TNF was less effective in the absence of CD31, while reduction of CD31 reduced shear-sensitivity in some genes (e.g., eNOS), but not others (e.g., KLF-2). Thus, CD31 played a role in shear-sensitivity of some genes and of neutrophil recruitment, but not in modulation of endothelial migration. Different mechanotransducers may mediate different functional effects of shear stress. Hence, identification of the specific pathways may provide targets for therapeutic manipulation of angiogenesis or inflammation.

The role of non-hematopoietic stromal cells in the persistence of inflammation.

Inflammation results from the complex interaction between hematopoietic and stromal cells and growing evidence supports a key role for the stroma in driving the switch from acute resolving to persistence in chronic inflammatory diseases. Stromal cells have also been shown to play a critical role in cancer biology, being involved in cancer growth, dissemination, and inhibition of the autologous immune response, ultimately favoring persistence and metastatic spread. Similarly, blood and lymphatic endothelial cells contribute to tissue homeostasis during physiological inflammation but also lead to discorded leukocyte and tumor cell accumulation in pathological inflammation and cancer. This review aims to summarize the role that pathogenic stroma plays in the pathogenesis of diseases such as cancer and chronic inflammation.

Influence of stromal cells on lymphocyte adhesion and migration on endothelial cells.

Methods are described for analysing adhesion and migration of isolated lymphocytes on endothelial cell monolayers which have been co-cultured with different stromal cells, with or without additional cytokine treatment. The different cells types are grown on opposite sides of 3.0- or 0.4-mum pore filters depending on whether migration through the whole construct is to be analysed or adhesion to the endothelial cells alone. Assays may be "static" or filters can be incorporated into flow chambers so that cell behaviour can be directly observed under conditions simulating those in vivo. In general, by choice of method, one can evaluate efficiency of attachment and ability of cells to migrate across the endothelial monolayer, through the filter and through the stromal cell layer. Fluorescence microscopic examination of fixed filters can be used, e.g. to ascertain whether lymphocytes are retained by stromal cells. In general, static assays have the higher throughput and greatest ease of use, while the flow-based assays are more physiologically relevant and allow detailed recording of cell behaviour in real time.

Ly49H+ NK cells migrate to and protect splenic white pulp stroma from murine cytomegalovirus infection.

In this study, we show that in the absence of a protective NK cell response, murine CMV causes destruction of splenic white and red pulp pulp areas in the first few days of infection. Destruction of T zone stroma is associated with almost complete loss of dendritic cells and T cells. We provide evidence that the virus replicates in red and white pulp stroma in vivo and in vitro. Control of white pulp viral replication is associated with migration of murine CMV-specific activated NK cells to white pulp areas, where they associate directly with podoplanin-expressing T zone stromal cells. Our data explain how NK cells protect the lymphoid-rich white pulp areas from CMV, allowing protective adaptive T cell-dependent immune responses to develop, and how this mechanism might break down in immunocompromised patients.

Minimal regulation of platelet activity by PECAM-1.

PECAM-1 is a member of the superfamily of immunoglobulins (Ig) and is expressed on platelets at moderate level. PECAM-1 has been reported to have contrasting effects on platelet activation by the collagen receptor GPVI and the integrin, alphaIIbbeta3, even though both receptors signal through Src-kinase regulation of PLCgamma2. The present study compares the role of PECAM-1 on platelet activation by these two receptors and by the lectin receptor, CLEC-2, which also signals via PLCgamma2. Studies using PECAM-1 knockout-mice and cross-linking of PECAM-1 using specific antibodies demonstrated a minor inhibitory role on platelet responses to the above three receptors and also under some conditions to the G-protein agonist thrombin. The degree of inhibition was considerably less than that produced by PGI2, which elevates cAMP. There was no significant difference in thrombus formation on collagen in PECAM-1-/- platelets relative to litter-matched controls. The very weak inhibitory effect of PECAM-1 on platelet activation relative to that of PGI2 indicate that the Ig-receptor is not a major regulator of platelet activation. PECAM-1 has been reported to have contrasting effects on platelet activation. The present study demonstrates a very mild or negligible effect on platelet activation in response to stimulation by a variety of agonists, thereby questioning the physiological role of the immunoglobulin receptor as a major regulator of platelet activation.

A novel role for PECAM-1 in megakaryocytokinesis and recovery of platelet counts in thrombocytopenic mice.

During thrombopoiesis, maturing megakaryocytes (MKs) migrate within the complex bone marrow stromal microenvironment from the proliferative osteoblastic niche to the capillary-rich vascular niche where proplatelet formation and platelet release occurs. This physiologic process involves proliferation, differentiation, migration, and maturation of MKs before platelet production occurs. In this study, we report a role for the glycoprotein PECAM-1 in thrombopoiesis. We show that following induced thrombocytopenia, recovery of the peripheral platelet count is impaired in PECAM-1-deficient mice. Whereas MK maturation, proplatelet formation, and platelet production under in vitro conditions were unaffected, we identified a migration defect in PECAM-1-deficient MKs in response to a gradient of stromal cell-derived factor 1 (SDF1), a major chemokine regulating MK migration within the bone marrow. This defect could be explained by defective PECAM-1(-/-) MK polarization of the SDF1 receptor CXCR4 and an increase in adhesion to immobilized bone marrow matrix proteins that can be explained by an increase in integrin activation. The defect of migration and polarization was confirmed in vivo with demonstration of altered spatial localization of MKs within the bone marrow in PECAM-1-deficient mice, following immune-induced thrombocytopenia. This study identifies a novel role for PECAM-1 in regulating MK migration and thrombopoiesis.

Analysis of host response to bacterial infection using error model based gene expression microarray experiments.

A key step in the analysis of microarray data is the selection of genes that are differentially expressed. Ideally, such experiments should be properly replicated in order to infer both technical and biological variability, and the data should be subjected to rigorous hypothesis tests to identify the differentially expressed genes. However, in microarray experiments involving the analysis of very large numbers of biological samples, replication is not always practical. Therefore, there is a need for a method to select differentially expressed genes in a rational way from insufficiently replicated data. In this paper, we describe a simple method that uses bootstrapping to generate an error model from a replicated pilot study that can be used to identify differentially expressed genes in subsequent large-scale studies on the same platform, but in which there may be no replicated arrays. The method builds a stratified error model that includes array-to-array variability, feature-to-feature variability and the dependence of error on signal intensity. We apply this model to the characterization of the host response in a model of bacterial infection of human intestinal epithelial cells. We demonstrate the effectiveness of error model based microarray experiments and propose this as a general strategy for a microarray-based screening of large collections of biological samples.

Apoptosis disables CD31-mediated cell detachment from phagocytes promoting binding and engulfment.

Macrophage recognition and ingestion of 'self' cells undergoing apoptosis in vivo protects tissues from the toxic contents of dying cells and modulates macrophage regulation of inflammatory and immune responses. However, the complex molecular mechanisms mediating macrophage discrimination between viable and apoptotic cells are poorly understood. In particular, little is known of why viable nucleated cells are not engulfed by macrophages. To reveal active repulsion of viable cells and to seek specific capture or 'tethering' of apoptotic cells, we studied macrophage binding of viable and apoptotic leukocytes under conditions of flow. We found that homophilic ligation of CD31 (ref. 4) on viable leukocytes promoted their active, temperature-dependent detachment under low shear, whereas such CD31-mediated detachment was disabled in apoptotic leukocytes, promoting tight binding and macrophage ingestion of dying cells. Here we propose that CD31 (also known as platelet-endothelial cell adhesion molecule-1, PECAM-1) is an example of a cell-surface molecule that prevents phagocyte ingestion of closely apposed viable cells by transmitting 'detachment' signals, and which changes function on apoptosis, promoting tethering of dying cells to phagocytes.