Inflammatory disease status and response to TNF blockade are associated with mechanisms of endotoxin tolerance.

The mechanisms of endotoxin tolerance (ET), which down-regulate inflammation, are well described in response to exogenous toll-like receptor ligands, but few studies have focused on ET-associated mechanisms in inflammatory disease. As blocking TNF can attenuate the development of ET, the effect of anti-TNF on the expression of key ET-associated molecules in inflammatory auto-immune disease was measured; changes in inflammatory gene expression were confirmed using an ET bioassay. The expression of immunomodulatory molecules was measured in a murine model of arthritis treated with anti-TNF and the expression of ET-associated molecules was measured in whole blood in rheumatoid arthritis (RA) and ankylosing spondylitis (AS) patients, before and after therapy. The expression of ET-associated genes was also measured in RA patient monocytes before and after therapy, in anti-TNF responders and non-responders. Tnfaip3, Ptpn6 and Irak3 were differentially expressed in affected paws, spleens, lymph nodes and circulating leucocytes in experimental murine arthritis treated with anti-TNF. Prior to therapy, the expression of TNFAIP3, INPP5D, PTPN6, CD38 and SIGIRR in whole blood differed between human healthy controls and RA or AS patients. In blood monocytes from RA patients, the expression of TNFAIP3 was significantly reduced by anti-TNF therapy in non-responders. Prior to therapy, anti-TNF non-responders had higher expression of TNFAIP3 and SLPI, compared to responders. Although the expression of TNFAIP3 was significantly higher in RA non-responders prior to treatment, the post-treatment reduction to a level similar to responders did not coincide with a clinical response to therapy.

Histone H3K27me3 demethylases regulate human Th17 cell development and effector functions by impacting on metabolism.

T helper (Th) cells are CD4+ effector T cells that play a critical role in immunity by shaping the inflammatory cytokine environment in a variety of physiological and pathological situations. Using a combined chemico-genetic approach, we identify histone H3K27 demethylases KDM6A and KDM6B as central regulators of human Th subsets. The prototypic KDM6 inhibitor GSK-J4 increases genome-wide levels of the repressive H3K27me3 chromatin mark and leads to suppression of the key transcription factor RORγt during Th17 differentiation. In mature Th17 cells, GSK-J4 induces an altered transcriptional program with a profound metabolic reprogramming and concomitant suppression of IL-17 cytokine levels and reduced proliferation. Single-cell analysis reveals a specific shift from highly inflammatory cell subsets toward a resting state upon demethylase inhibition. The root cause of the observed antiinflammatory phenotype in stimulated Th17 cells is reduced expression of key metabolic transcription factors, such as PPRC1. Overall, this leads to reduced mitochondrial biogenesis, resulting in a metabolic switch with concomitant antiinflammatory effects. These data are consistent with an effect of GSK-J4 on Th17 T cell differentiation pathways directly related to proliferation and include regulation of effector cytokine profiles. This suggests that inhibiting KDM6 demethylases may be an effective, even in the short term, therapeutic target for autoimmune diseases, including ankylosing spondylitis.

Disease status in human and experimental arthritis, and response to TNF blockade, is associated with MHC class II invariant chain (CD74) isoform expression.

Splice variants of CD74 differentially modulate the activity of cathepsin L (CTSL). As CD74 and CTSL participate in the pathogenesis of inflammatory diseases such as rheumatoid arthritis (RA), we determined whether splice variants of CD74 could be biomarkers of disease activity. Gene expression was measured in mice with collagen-induced arthritis using quantitative PCR (qPCR). In vitro studies using murine macrophage/DC-lineage cells determined the relative influence of macrophage phenotype on isoform expression and the potential to produce CTSL in response to TNF. CD74 splice variants were measured in human RA synovium and RA patients' monocytes. In arthritic mice, the expression of the p41 CD74 isoform was significantly higher in severely affected paws compared with unaffected paws or the paws of naïve mice; the p41 isoform significantly correlated with the expression of TNF in arthritic paws. Compared with M2-like macrophages, M1-like macrophages expressed increased levels of CD74 and had higher expression, secretion and activity of CTSL. RA patients that responded to TNF blockade had significantly higher expression levels of CD74 in circulating monocytes after treatment, compared with non-responders. The expression of the human CD74 isoform a was significantly higher in RA synovia, compared with osteoarthritis synovia, and was associated with CSTL enzymatic activity. This study is the first to demonstrate differential expression of the CD74 p41 isoform in an auto-immune disorder and in response to therapy. The differential expression of CD74 splice variants indicates an association, and potentially a mechanistic role, in the pathogenesis of RA.

TLR expression profiles are a function of disease status in rheumatoid arthritis and experimental arthritis.

The role of the innate immune system has been established in the initiation and perpetuation of inflammatory disease, but less attention has been paid to its role in the resolution of inflammation and return to homeostasis. Toll-like receptor (TLR) expression profiles were analysed in tissues with differing disease status in rheumatoid arthritis (RA), ankylosing spondylitis (AS), and in experimental arthritis. TLR gene expression was measured in whole blood and monocytes, before and after TNF blockade. In RA and osteoarthritis synovia, the expression of TLRs was quantified by standard curve qPCR. In addition, four distinct stages of disease were defined and validated in collagen-induced arthritis (CIA), the gold standard animal model for RA - pre-onset, early disease, late disease and immunised mice that were resistant to the development of disease. TLR expression was measured in spleens, lymph nodes, blood cells, liver and the paws (inflamed and unaffected). In RA whole blood, the expression of TLR1, 4 and 6 was significantly reduced by TNF blockade but the differences in TLR expression profiles between responders and non-responders were less pronounced than the differences between RA and AS patients. In RA non-responders, monocytes had greater TLR2 expression prior to therapy compared to responders. The expression of TLR1, 2, 4 and 8 was higher in RA synovium compared to control OA synovium. Circulating cytokine levels in CIA resistant mice were similar to naïve mice, but anti-collagen antibodies were similar to arthritic mice. Distinct profiles of inflammatory gene expression were mapped in paws and organs with differing disease status. TLR expression in arthritic paws tended to be similar in early and late disease, with TLR1 and 2 moderately higher in late disease. TLR expression in unaffected paws varied according to gene and disease status but was generally lower in resistant paws. Disease status-specific profiles of TLR expression were observed in spleens, lymph nodes, blood cells and the liver. Notably, TLR2 expression rose then fell in the transition from naïve to pre-onset to early arthritis. TLR gene expression profiles are strongly associated with disease status. In particular, increased expression in the blood precedes clinical manifestation.

Inhibition of histone H3K27 demethylases selectively modulates inflammatory phenotypes of natural killer cells.

Natural killer (NK) cells are innate lymphocytes, important in immune surveillance and elimination of stressed, transformed, or virus-infected cells. They critically shape the inflammatory cytokine environment to orchestrate interactions of cells of the innate and adaptive immune systems. Some studies have reported that NK cell activation and cytokine secretion are controlled epigenetically but have yielded only limited insight into the mechanisms. Using chemical screening with small-molecule inhibitors of chromatin methylation and acetylation, further validated by knockdown approaches, we here identified Jumonji-type histone H3K27 demethylases as key regulators of cytokine production in human NK cell subsets. The prototypic JMJD3/UTX (Jumonji domain-containing protein 3) H3K27 demethylase inhibitor GSK-J4 increased global levels of the repressive H3K27me3 mark around transcription start sites of effector cytokine genes. Moreover, GSK-J4 reduced IFN-γ, TNFα, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-10 levels in cytokine-stimulated NK cells while sparing their cytotoxic killing activity against cancer cells. The anti-inflammatory effect of GSK-J4 in NK cell subsets, isolated from peripheral blood or tissue from individuals with rheumatoid arthritis (RA), coupled with an inhibitory effect on formation of bone-resorbing osteoclasts, suggested that histone demethylase inhibition has broad utility for modulating immune and inflammatory responses. Overall, our results indicate that H3K27me3 is a dynamic and important epigenetic modification during NK cell activation and that JMJD3/UTX-driven H3K27 demethylation is critical for NK cell function.

A retrospective series of conditions and mortality associated with extreme hyperferritinaemia in adults.

BACKGROUND: Serum ferritin is commonly used in the diagnosis of iron deficiency anaemia. However, extreme hyperferritinaemia suggests a significant illness, including the differential diagnosis of haemophagocytic lymphohistiocytosis (HLH), which is rare and associated with a high mortality, particularly if untreated. This series aims to identify the causes and associated mortality of severe hyperferritinaemia in patients seen at a teaching hospital in London, UK. METHOD: Demographic and medical data were collected for all patients over 18 years of age with extreme hyperferritinaemia (defined as serum ferritin levels of ≥4000 mcg/L). Conditions associated with hyperferritinaemia and in-hospital mortality were identified from medical records, laboratory data and discharge and death notification. RESULTS: One hundred and fifty-five cases of extreme hyperferritinaemia in adults were identified. Associated conditions included iron overload (35%), malignancy (24%), infectious disease (21%) and hepatocellular disease (12%). Autoimmune disease and HLH resulted in significantly higher median peak ferritin levels compared with all cases (10 616 mcg/L, P < .01 and 19 138 mcg/L, P < .05, respectively). Patients with confirmed HLH had the highest median peak ferritin. Uncommon infections were identified in this series, and included such as dengue, syphilis, HIV and murine typhus. HLH had been confirmed in seven patients (5%). In five patients (3%) no clear cause for raised ferritin was identified. Overall mortality in the whole cohort was 14% (n = 22), but there was a very high mortality of 80% in the group where no cause was found for the hyperferritinaemia, and these patients were significantly more likely to die during the index admission (P < .01). CONCLUSION: Extreme hyperferritinaemia is associated with a broad differential diagnosis of significant medical conditions, including iron overload, infections, cancer and liver disease. Rare infectious causes were also identified, and this series reports a greater proportion of cases of HLH than has previously reported. Unexplained hyperferritinaemia was associated with significant mortality.

Diagnosing water security in the rural North with an environmental security framework.

This study explores the nature of water security challenges in rural Alaska, using a framework for environmental security that entails four interrelated concepts: availability, access, utility, and stability of water resources. Many researchers and professionals agree that water insecurity is a problem in rural Alaska, although the scale and nature of the problem is contested. Some academics have argued that the problem is systemic, and rooted in an approach to water security by the state that prioritizes economic concerns over public health concerns. Health practitioners and state agencies, on the other hand, contend that much progress has been made, and that nearly all rural households have access to safe drinking water, though many are still lacking 'modern' in-home water service. Here, we draw on a synthesis of ethnographic research alongside data from state agencies to show that the persistent water insecurity problems in rural Alaska are not a problem of access to or availability of clean water, or a lack of 'modern' infrastructure, but instead are rooted in complex human dimensions of water resources management, including the political legacies of state and federal community development schemes that did not fully account for local needs and challenges. The diagnostic approach we implement here helps to identify solutions to these challenges, which accordingly focus on place-based needs and empowering local actors. The framework likewise proves to be broadly applicable to exploring water security concerns elsewhere in the world.

A novel upstream enhancer of FOXP3, sensitive to methylation-induced silencing, exhibits dysregulated methylation in rheumatoid arthritis Treg cells.

Treg-cell function is compromised in rheumatoid arthritis (RA). As the master regulator of Treg cells, FOXP3 controls development and suppressive function. Stable Treg-cell FOXP3 expression is epigenetically regulated; constitutive expression requires a demethylated Treg-specific demethylated region. Here, we hypothesised that methylation of the FOXP3 locus is altered in Treg cells of established RA patients. Methylation analysis of key regulatory regions in the FOXP3 locus was performed on Treg cells from RA patients and healthy controls. The FOXP3 Treg-specific demethylated region and proximal promoter displayed comparable methylation profiles in RA and healthy-donor Treg cells. We identified a novel differentially methylated region (DMR) upstream of the FOXP3 promoter, with enhancer activity sensitive to methylation-induced silencing. In RA Treg cells we observed significantly reduced DMR methylation and lower DNA methyltransferase (DNMT1/3A) expression compared with healthy Treg cells. Furthermore, DMR methylation negatively correlated with FOXP3 mRNA expression, and Treg cells isolated from rheumatoid factor negative RA patients were found to express significantly higher levels of FOXP3 than Treg cells from RhF-positive patients, with an associated decrease in DMR methylation. In conclusion, the novel DMR is involved in the regulation of Treg-cell FOXP3 expression, but this regulation is lost post-transcriptionally in RA Treg cells.

Primary care attitudes to methotrexate monitoring.

BACKGROUND: Rheumatoid arthritis affects 1% of the UK population. First-line treatment is with the immunosuppressant, methotrexate (MTX). This is generally regarded as a safe and effective medication when taken at the right dose, with appropriate monitoring. Very occasionally it causes serious harm or death. In 2006, the National Patient Safety Agency issued a safety alert following increasing reports of prescribing errors and toxicity. Over the last decade, Northwick Park Hospital has seen two MTX-related deaths and other morbidity. Repeat prescriptions and monitoring are generally undertaken in primary care, although concerns have been raised about variation in local practice. Poor communication and inadequate monitoring are safety concerns. Duplication of monitoring has cost implications. Local (hospital Shared Care Guidelines (SCG) ) and national guidelines, from the British Society of Rheumatology (BSR), on MTX monitoring are freely available and accessible. METHOD: We surveyed our local GP community to better understand their practice and establish where patient care could be improved. RESULTS: We contacted 86 practices, of which 31 replied (a response rate of 36%). On average, there was one patient on MTX per 743 in the practice (0.13%), ranging from 0-0.5%. All GPs admitted they repeated MTX prescriptions, but only 77.4% monitored these. Of those who did monitor, 58.6% were aware of local guidelines and only 48.4% were aware of national guidelines. A total of 26.7% of GPs were monitoring and prescribing MTX but not aware of any guidelines. Among this number, 37.5% did not feel they needed further education. CONCLUSION: Serious safety concerns have been raised, including the poor response rate. Any doctor prescribing MTX should also be monitoring according to guidelines. Low numbers of patients on MTX per practice are surprising, possibly reflecting inadequate records or under-diagnosis. With these data, we have encouraged commissioners to fund a computer monitoring system accessible to primary and secondary care for improved patient safety, and to ultimately save costs by reducing duplication of work.

Dissecting the Role of BET Bromodomain Proteins BRD2 and BRD4 in Human NK Cell Function.

Natural killer (NK) cells are innate lymphocytes that play a pivotal role in the immune surveillance and elimination of transformed or virally infected cells. Using a chemo-genetic approach, we identify BET bromodomain containing proteins BRD2 and BRD4 as central regulators of NK cell functions, including direct cytokine secretion, NK cell contact-dependent inflammatory cytokine secretion from monocytes as well as NK cell cytolytic functions. We show that both BRD2 and BRD4 control inflammatory cytokine production in NK cells isolated from healthy volunteers and from rheumatoid arthritis patients. In contrast, knockdown of BRD4 but not of BRD2 impairs NK cell cytolytic responses, suggesting BRD4 as critical regulator of NK cell mediated tumor cell elimination. This is supported by pharmacological targeting where the first-generation pan-BET bromodomain inhibitor JQ1(+) displays anti-inflammatory effects and inhibit tumor cell eradication, while the novel bivalent BET bromodomain inhibitor AZD5153, which shows differential activity towards BET family members, does not. Given the important role of both cytokine-mediated inflammatory microenvironment and cytolytic NK cell activities in immune-oncology therapies, our findings present a compelling argument for further clinical investigation.

SARS-CoV-2 outbreak in immune-mediated inflammatory diseases: the Euro-COVIMID multicentre cross-sectional study.

BACKGROUND: The COVID-19 pandemic has raised numerous questions among patients with immune-mediated inflammatory diseases regarding potential reciprocal effects of COVID-19 and their underlying disease, and potential effects of immunomodulatory therapy on outcomes related to COVID-19. The seroprevalence of SARS-CoV-2 and factors associated with symptomatic COVID-19 in patients with immune-mediated inflammatory diseases are still unclear. The Euro-COVIMID study aimed to determine the serological and clinical prevalence of COVID-19 among patients with immune-mediated inflammatory diseases, as well as factors associated with COVID-19 occurrence and the impact of the pandemic in its management. METHODS: In this multicentre cross-sectional study, patients aged 18 years or older with a clinical diagnosis of rheumatoid arthritis, axial spondyloarthritis, systemic lupus erythematosus, Sjögren's syndrome, or giant cell arteritis were recruited from six tertiary referral centres in France, Germany, Italy, Portugal, Spain, and the UK. Demographics, comorbidities, treatments, and recent disease flares, as well as information on COVID-19 symptoms, were collected through a questionnaire completed by participants. SARS-CoV-2 serology was systematically tested. The main outcome was the serological and clinical prevalence of COVID-19. Factors associated with symptomatic COVID-19 were assessed by multivariable logistic regression, and incidence of recent disease flares, changes in treatments for underlying disease, and the reasons for treatment changes were also assessed. This study is registered with ClinicalTrials.gov, NCT04397237. FINDINGS: Between June 7 and Dec 8, 2020, 3136 patients with an immune-mediated inflammatory disease answered the questionnaire. 3028 patients (median age 58 years [IQR 46-67]; 2239 [73·9%] women and 789 [26·1%] men) with symptomatic COVID-19, serological data, or both were included in analyses. SARS-CoV-2 antibodies were detected in 166 (5·5% [95% CI 4·7-6·4]) of 3018 patients who had serology tests. Symptomatic COVID-19 occurred in 122 (4·0% [95% CI 3·4-4·8]) of 3028 patients, of whom 24 (19·7%) were admitted to hospital and four (3·3%) died. Factors associated with symptomatic COVID-19 were higher concentrations of C-reactive protein (odds ratio 1·18, 95% CI 1·05-1·33; p=0·0063), and higher numbers of recent disease flares (1·27, 1·02-1·58; p=0·030), whereas use of biological therapy was associated with reduced risk (0·51, 0·32-0·82; p=0·0057). At least one disease flare occurred in 654 (21·6%) of 3028 patients. Over the study period, 519 (20·6%) of 2514 patients had treatment changes, of which 125 (24·1%) were due to the pandemic. INTERPRETATION: This study provides key insights into the epidemiology and risk factors of COVID-19 among patients with immune-mediated inflammatory diseases. Overall, immunosuppressants do not seem to be deleterious in this scenario, and the control of inflammatory activity seems to be key when facing the pandemic. FUNDING: Pfizer, Sanofi, Amgen, Galapagos, and Lilly.

Guillain-Barré syndrome complicated by takotsubo cardiomyopathy: an under-recognised association.

A 41-year-old woman was admitted with progressive paraesthesia and weakness and was diagnosed with Guillain-Barré syndrome. Following an initial period of recovery with intravenous immunoglobulin treatment, she developed acute chest pain associated with electrocardiographic changes. Investigations excluded acute coronary syndrome and instead confirmed a diagnosis of takotsubo cardiomyopathy, which was treated medically. The patient made an excellent neurological and cardiac recovery. Here we discuss the rarely described association between these two conditions and suggest that patients admitted with Guillain-Barré syndrome may benefit from routine screening with echocardiography.

Diagnosis, management and prevention of scleroderma renal disease.

PURPOSE OF REVIEW: Renal complications are important in scleroderma (systemic sclerosis) and include scleroderma renal crisis. This is a medical emergency that requires careful management. Recent cohort studies have highlighted key aspects of management and outcome and these are reviewed. RECENT FINDINGS: Two recent articles have reported the course of scleroderma renal crisis, and examined risk factors, clinical outcomes and prognostic markers in large contemporary scleroderma cohorts. Diffuse skin disease, early rapidly progressing skin disease, anti-RNA polymerase antibodies and genetic factors are all nonmodifiable risk factors. Use of corticosteroids is associated with scleroderma renal crisis. Over half of cases of scleroderma renal crisis require dialysis; just under half of these will be able to discontinue dialysis over the following 2 years. Despite clear improvement in 12-month survival, which is a testament to the efficacy of angiotensin-converting enzyme inhibitors in renal crisis, long-term mortality remains significant, especially with ongoing dialysis. SUMMARY: Renal involvement remains a major complication of scleroderma. Long-term outcome after renal crisis remains poor despite the use of angiotensin-converting enzyme inhibitors. There is no evidence at present to support the use of angiotensin-converting enzyme inhibitors prophylactically. The mechanisms and significance of chronic renal impairment in scleroderma need to be better defined.

Biologic therapies in autoimmune diseases.

Over the past decade, the treatment of rheumatoid arthritis has been revolutionised by the development of therapies targeted at molecules involved in driving the inflammatory response. This review briefly summarises the established uses of biologic therapies in rheumatoid disease, and outlines other diseases in rheumatology and other fields where biologic agents are finding a role.

Unusual cause of flare in antineutrophil cytoplasmic antibody-associated vasculitis.

A 53-year-old woman attended for a routine outpatient appointment for follow-up of antineutrophil cytoplasmic antibody-positive vasculitis. Her disease had relapsed despite appropriate medical management with mycophenolate mofetil (MMF), as evidenced by rising acute phase response and antimyeloperoxidase titre with ongoing symptoms. On further questioning, she had been taking oral charcoal as part of a detoxification diet, which we postulate was causing significantly impaired MMF absorption. This case report summarises the presentation and highlights the importance of a thorough drug history, and should prompt the reader to keep an open mind with regard to drug interactions and treatment regimen adherence when treatment is, unexpectedly, seemingly failing.