How does infliximab work in rheumatoid arthritis?

Since the initial characterization of tumor necrosis factor alpha (TNFalpha), it has become clear that TNFalpha has diverse biologic activity. The realization that TNFalpha plays a role in rheumatoid arthritis (RA) has led to the development of anti-TNF agents for the treatment of RA. Infliximab, a chimeric monoclonal antibody that specifically, and with high affinity, binds to TNFalpha and neutralizes the cytokine, is currently approved for the treatment of RA and Crohn's disease, another immune-inflammatory disorder. In addition to establishing the safety and efficacy of infliximab, clinical research has also provided insights into the complex cellular and cytokine-dependent pathways involved in the pathophysiology of RA, including evidence that supports TNFalpha involvement in cytokine regulation, cell recruitment, angiogenesis, and tissue destruction.     

How do sinking phytoplankton species manage to persist?

Phytoplankton require light for photosynthesis. Yet, most phytoplankton species are heavier than water and therefore sink. How can these sinking species persist? Somehow, the answer should lie in the turbulent motion that redisperses sinking phytoplankton over the vertical water column. Here, we show, using a reaction-advection-diffusion equation of light-limited phytoplankton, that there is a turbulence window sustaining sinking phytoplankton species in deep waters. If turbulent diffusion is too high, phytoplankton are mixed to great depths, and the depth-averaged light conditions are too low to allow net positive population growth. Conversely, if turbulent diffusion is too low, sinking phytoplankton populations end up at the ocean floor and succumb in the dark. At intermediate levels of turbulent diffusion, however, phytoplankton populations can outgrow both mixing rates and sinking rates. In this way, the reproducing population as a whole can maintain a position in the well-lit zone near the top of the water column, even if all individuals within the population have a tendency to sink. This theory unites earlier classic results by Sverdrup and Riley as well as our own recent findings and provides a new conceptual framework for the understanding of phytoplankton dynamics under the influence of mixing processes.     

Circulating cytokine pattern and factors describing rheumatoid arthritis: IL-15 as one of the biomarkers for RA?

The aim of study was to examine relationship among levels of cytokines (IL-6, IL-13, IL-15, TNF-α) and chemokine (IL-8), production of autoantibodies, radiographic progression, and factors describing rheumatoid arthritis (RA). A total of 156 RA patients according to ACR criteria, and 55 control subjects were recruited into study. We observed higher levels of IL-15 within RA patients compared to healthy controls. Correlations among cytokine levels and the measures of rheumatoid factors, anti-CCP, measures of disease activity, and radiographic progression were observed. We conclude that IL-15 level in circulation could serve as one of the biomarkers for RA detection.     

How do fishes manage disease?

Disease drives the evolution of proactive and reactive mitigation behaviours in fishes as for terrestrial animals. Understanding fish self-remedy behaviours could discover algal bioactives, reveal novel strategies for disease management, identify new habitats or ecosystems critical to population health and conservation, and enhance knowledge of interspecific evolutionary relationships and communication.     

Interferon-beta for treatment of rheumatoid arthritis?

IFN-beta treatment is emerging as a potentially effective form of therapy in various immune-mediated conditions. The present review addresses the possible role of IFN-beta in immune-mediated diseases such as multiple sclerosis and rheumatoid arthritis. Several placebo-controlled trials are discussed, as are the available immunological data that are relevant to this field. Review of these data provides evidence that IFN-beta has some beneficial therapeutic effect in patients with relapsing-remitting multiple sclerosis and might also have antirheumatic potential. This notion is supported by recent studies showing a critical role for IFN-beta in bone homeostasis.     

Epstein-Barr virus and rheumatoid arthritis: is there a link?

Rheumatoid arthritis is a systemic autoimmune disease characterized by chronic, destructive, debilitating arthritis. Its etiology is unknown; it is presumed that environmental factors trigger development in the genetically predisposed. Epstein-Barr virus, a nearly ubiquitous virus in the human population, has generated great interest as a potential trigger. This virus stimulates polyclonal lymphocyte expansion and persists within B lymphocytes for the host's life, inhibited from reactivating by the immune response. In latent and replicating forms, it has immunomodulating actions that could play a role in the development of this autoimmune disease. The evidence linking Epstein-Barr virus and rheumatoid arthritis is reviewed.     

MMP-2, TNF-α and NLRP1 polymorphisms in Chinese patients with ankylosing spondylitis and rheumatoid arthritis

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are autoimmune, inflammatory diseases with substantial genetic contributions. Matrix metalloproteinase (MMP)-2, tumor necrosis factor (TNF)-α and NLR family pyrin domain-containing 1 (NLRP1) play important roles in the immune response. We studied the MMP-2 rs243865 C/T, TNF-α rs1800629 A/G, NLRP1 rs878329 C/G and NLRP1 rs6502867 C/T polymorphisms in a Chinese cohort of 520 patients with RA, 100 with AS and 520 controls. Genotyping was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Using the MMP-2 rs243865 CC homozygote genotype as the reference group, the CT and TT/CT genotypes were associated with significantly reduced risks of AS. However, logistic regression analyses revealed that the MMP-2 rs243865 C/T polymorphism was not associated with risk of RA. TNF-α rs1800629 A/G, NLRP1 rs878329 C/G and NLRP1 rs6502867 C/T polymorphisms were not associated with risk of RA or AS. These findings suggest that the MMP-2 rs243865 C/T polymorphism is associated with AS development.     

How useful are the genetic markers in attempts to understand and manage marine biodiversity?

The genetics of marine populations is a subject that has made little progress compared with the effort spent on the terrestrial environment. This is so despite “applied” aspects such as stock management, marine aquaculture, creation of reserves, conservation of the coastal zones, taxonomy, and protection of species. The crowded and dispersive marine environment, with its steep physical gradients, favours the existence of a planktonic larval stage for most species. The attendant high fecundity has important consequences for selection differentials and dispersal and therefore for the evolution of genetic structures. These features must be taken into account in order to understand the origin and maintenance of marine biodiversity and, in some cases, to manage it.In this article, after a definition of genetic diversity among other aspects of biodiversity, special features of the marine environment and processes governing genetic diversity are given together with the molecular tools required to study it. Then, an overview of the interesting scientific questions in marine biodiversity research is given concerning:

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the population structure as a function of dispersal systems and spatial constraints: gene flow and speciation in a dispersive environment,

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the phylogeography and historical biogeography of marine ecosystems;

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the functional and adaptive aspects of polymorphism: larval phase and genetic control of recruitment.

Some uses of genetic diversity for assessment, conservation and protection purposes are also detailed. Organismal (specific) diversity does not enter the scope of the article.     

How to diagnose and manage Cushing's disease during pregnancy, when hypercortisolism is mild?

Diagnosis of mild Cushing's disease (CD) can be difficult in pregnant women, because its clinical and biochemical features can be erroneously interpreted as consequence of the gestation. Corticotropin releasing hormone (CRH) and desmopressin (DDAVP) tests are currently used to confirm CD, but data concerning adrenocorticotropic hormone (ACTH) response during pregnancy are lacking. A woman with mild cushingoid features was evaluated during the first trimester of gestation. Serum cortisol was normal at morning, but increased at midnight and incompletely suppressed by 1-mg dexamethasone overnight administration. Also 24-h urinary free cortisol levels were mildly elevated. She delivered vaginally a healthy newborn at the 39th week of an uneventful pregnancy. After delivery, an ACTH-secreting microadenoma was surgically removed. During the first trimester of gestation and after delivery, human CRH (h-CRH) and DDAVP-stimulated ACTH peaks were higher than those measured in 22 healthy premenopausal women. While the ACTH/h-CRH peak was intermediate between those measured in the healthy women and in 9 CD female patients, ACTH/DDAVP peak was in the range of CD patients and dramatically higher than those of healthy women. However, ACTH increase after h-CRH was significantly higher after delivery than during gestation (p?相似文献   

Genetic epidemiology of rheumatoid arthritis: what to expect from Latin America?

Rheumatoid arthritis is a chronic and systemic autoimmune disease characterized by inflammation and destruction of the synovial joints. It affects approximately 0.5% of the Latin-American population and is three times more common in women than in men. Evidence of familial aggregation (lambdas=2-17) was the first indication of a genetic susceptibility to disease. As in other autoimmune diseases, it has a complex genetic basis. Results from whole-genome scans indicate that the HLA region contains a significant and consistent set of linked loci. However, HLA accounts for only one-third of the genetic susceptibility of disease, indicating that non-HLA genes are also involved in the disease susceptibility. In Latin-America, association with HLA-DRB1*0404 and TNF -308A alleles has been uniformly established; however, many other candidate genes remain to be studied. The identification of genetic factors conferring susceptibility to rheumatoid arthritis will contribute to the knowledge of the pathogenic mechanisms, ability to predict its occurrence, the development of diagnostic tools, prognosis, and treatment. The genetic epidemiology of rheumatoid arthritis is herein reviewed; a set of recommendations is provided for the design, analysis and interpretation of genetic association studies in the context of Latin-American populations.     

Vitamin D deficiency: concern for rheumatoid arthritis and COVID-19?

Vitamin D is an immunomodulatory hormone with an established role in calcium and phosphate metabolism and skeletal mineralization. Evidence showing its immunological benefits by regulating essential components of the innate and adaptive immune system is prevalent. Vitamin D deficiency is reported worldwide and is thereby found to be associated with various immune-related diseases. Rheumatoid Arthritis and COVID-19 are two such diseases, sharing a similar hyperinflammatory response. Various studies have found an association of lower Vitamin D levels to be associated with both these diseases. However, contrasting data is also reported. We review here the available scientific data on risk factor association and supplementation benefits of Vitamin D in Rheumatoid Arthritis and COVID-19, intending to critically evaluate the literature.

     

Adiponectin: A biomarker for rheumatoid arthritis?

Recent achievements in the biology and the function of adipose tissue have regarded white adipose tissue (WAT) as an important endocrine and secretory organ. Releasing a series of multiple-function mediators, WAT is involved in a wide spectrum of diseases, including not only cardiovascular and metabolic complications, such as atherosclerosis and type 2 diabetes, but also inflammatory- and immune-related disorders, such as rheumatoid arthritis (RA) and osteoarthritis (OA). A large number of these mediators, called adipokines, such as tumor necrosis factor alpha (TNF-α), leptin, adiponectin, resistin, chemerin, interleukin-6 (IL-6), visfatin, and so on have been identified and studied widely. Important advances related to these proteins shed new insights into the pathophysiological mechanisms of many complicated diseases, although details of which remain unclear. Adiponectin, one of the most widely investigated adipokine, has been shown to possess both anti- and pro-inflammatory effects. RA is a chronic systemic inflammatory-related autoimmune disease. Accumulated evidence has demonstrated that cytokines and adipokines play an important role in the pathogenesis of RA. In this review, we have summarized the most recent advances in adiponectin research in the context of RA, focusing primarily on its effect on RA-related cells, its regulation on pro-inflammatory cytokines, as well as its validation as a biomarker for RA.     

Interferon-β for treatment of rheumatoid arthritis?

IFN-β treatment is emerging as a potentially effective form of therapy in various immune-mediated conditions. The present review addresses the possible role of IFN-β in immune-mediated diseases such as multiple sclerosis and rheumatoid arthritis. Several placebo-controlled trials are discussed, as are the available immunological data that are relevant to this field. Review of these data provides evidence that IFN-β has some beneficial therapeutic effect in patients with relapsing-remitting multiple sclerosis and might also have antirheumatic potential. This notion is supported by recent studies showing a critical role for IFN-β in bone homeostasis.     

Can baseline serum microRNAs predict response to TNF-alpha inhibitors in rheumatoid arthritis?

BackgroundIn rheumatoid arthritis, prediction of response to TNF-alpha inhibitor (TNFi) treatment would be of clinical value. This study aims to discover miRNAs that predict response and aims to replicate results of two previous studies addressing this topic.MethodsFrom the observational BiOCURA cohort, 40 adalimumab- (ADA) and 40 etanercept- (ETN) treated patients were selected to enter the discovery cohort and baseline serum profiling on 758 miRNAs was performed. The added value of univariately selected miRNAs (p < 0.05) over clinical parameters in prediction of response was determined by means of the area under the receiver operating characteristic curve (AUC-ROC). Validation was performed by TaqMan single qPCR assays in 40 new patients.ResultsExpression of miR-99a and miR-143 predicted response to ADA, and miR-23a and miR-197 predicted response to ETN. The addition of miRNAs increased the AUC-ROC of a model containing only clinical parameters for ADA (0.75 to 0.97) and ETN (0.68 to 0.78). In validation, none of the selected miRNAs significantly predicted response. miR-23a was the only overlapping miRNA compared to the two previous studies, however inversely related with response in one of these studies. The reasons for the inability to replicate previously proposed miRNAs predicting response to TNFi and replicate those from the discovery cohort were investigated and discussed.ConclusionsTo date, no miRNA consistently predicting response to TNFi therapy in RA has been identified. Future studies on this topic should meet a minimum of standards in design that are addressed in this study, in order to increase the reproducibility.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1085-z) contains supplementary material, which is available to authorized users.     

Plasma concentrations of amino acid and nicotinamide metabolites in rheumatoid arthritis – potential biomarkers of disease activity and drug treatment

This study aimed to evaluate changes in plasma amino acid and nicotinamide metabolites concentrations in rheumatoid arthritis (RA) in a search for potential biomarkers of the disease activity and the effect treatment. Analysis of plasma metabolite patterns with liquid chromatography/mass spectrometry revealed specific changes in RA as well as correlations with clinical parameters. Combined concentration parameter calculated as [aspartic acid]?+?[threonine]?+?[tryptophan]???[histidine]???[phenylalanine] offered the strongest correlation (p?<?0.001) with pain joint count, swollen joint count and DAS 28. Such analysis of amino acid and related metabolite pattern offers potential for diagnosis as well as for monitoring disease progression and therapy in RA.