Rheumatoid arthritis synovial fluid neutrophils drive inflammation through production of chemokines, reactive oxygen species and neutrophil extracellular traps

ABSTRACT Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting synovial joints. Neutrophils are believed to play an important role in both the initiation and progression of RA, and large numbers of activated neutrophils are found within both synovial fluid (SF) and synovial tissue from RA joints. In this study we analysed paired blood and SF neutrophils from patients with severe, active RA (DAS28> 5.1, n=3) using RNA-seq. 772 genes were significantly different between blood and SF neutrophils. IPA analysis predicted that SF neutrophils had increased expression of chemokines and ROS production, delayed apoptosis, and activation of signalling cascades regulating the production of NETs. This activated phenotype was confirmed experimentally by incubating healthy control neutrophils in cell-free RA SF, which was able to delay apoptosis and induce ROS production in both unprimed and TNF α primed neutrophils (p< 0.05). RA SF significantly increased neutrophil migration through 3mM transwell chambers (p< 0.05) and also increased production of NETs by healthy control neutrophils, including exposure of myeloperoxidase (MPO) and citrullinated histone-H3-positive DNA NETs. IPA analysis predicted NET production was mediated by signalling networks including AKT, RAF1, SRC and NF- κ B. Our results expand the understanding of the molecular changes that take place in the neutrophil transcriptome during migration into inflamed joints in RA, and the altered phenotype in RA SF neutrophils. Specifically, RA SF neutrophils lose their migratory properties, residing within the joint to generate signals that promote joint damage, as well as inflammation via recruitment and activation of both innate and adaptive immune cells. We propose that this activated SF neutrophil phenotype contributes to the chronic inflammation and progressive damage to cartilage and bone observed in patients with RA

The not so innocent bystander:an unusual cause of progressive breathlessness

This case report discusses a 76-year-old man who presented with symptomatic diffuse alveolar-septal and tracheobronchial amyloidosis with a low-grade monoclonal gammopathy. This patient had a combination of both symptomatic diffuse alveolar-septal interstitial disease and tracheobronchial amyloidosis, features that contradict the widely accepted presentations seen in this disease. First, tracheobronchial amyloidosis has been documented as localised disease without systemic involvement. Second, diffuse alveolar-septal interstitial disease is rarely identified with clinical symptoms unless there is significant cardiac involvement. This case highlights a number learning points in the diagnosis and management of systemic amyloid light chain amyloidosis;(1) There is a need for a high index of suspicion for diagnosis due to the potential subtlety of a plasma cell clone underlying AL amyloidosis, requiring serum-free light chain assays to increase sensitivity; (2) Haematological response and recovery of organ dysfunction are not a linear relationship due to the slower reversal of amyloid deposition; therefore, ongoing monitoring is required to identify those in need of repeated therapy. However, haematological response is a marker of overall survival and (3) Multisystem assessment and multidisciplinary collaboration are critical in optimising the care of patients with systemic AL amyloidosis.</p

Eukarion-134 Attenuates Endoplasmic Reticulum Stress-Induced Mitochondrial Dysfunction in Human Skeletal Muscle Cells

Maladaptive endoplasmic reticulum (ER) stress is associated with modified reactive oxygen species (ROS) generation and mitochondrial abnormalities; and is postulated as a potential mechanism involved in muscle weakness in myositis, an acquired autoimmune neuromuscular disease. This study investigates the impact of ROS generation in an in vitro model of ER stress in skeletal muscle, using the ER stress inducer tunicamycin (24 h) in the presence or absence of a superoxide dismutase/catalase mimetic Eukarion (EUK)-134. Tunicamycin induced maladaptive ER stress, which was mitigated by EUK-134 at the transcriptional level. ER stress promoted mitochondrial dysfunction, described by substantial loss of mitochondrial membrane potential, as well as a reduction in respiratory control ratio, reserve capacity, phosphorylating respiration, and coupling efficiency, which was ameliorated by EUK-134. Tunicamycin induced ROS-mediated biogenesis and fusion of mitochondria, which, however, had high propensity of fragmentation, accompanied by upregulated mRNA levels of fission-related markers. Increased cellular ROS generation was observed under ER stress that was prevented by EUK-134, even though no changes in mitochondrial superoxide were noticeable. These findings suggest that targeting ROS generation using EUK-134 can amend aspects of ER stress-induced changes in mitochondrial dynamics and function, and therefore, in instances of chronic ER stress, such as in myositis, quenching ROS generation may be a promising therapy for muscle weakness and dysfunction

The Effect of Food Insecurity Training on Knowledge, Awareness, Screening, and Intervention Practices within Two Pediatric Wards at an Academic Medical Center

Background and Introduction • Food insecurity is a major driver of preventable disease. Providers can screen to identify patients at risk for food insecurity using a two-question survey tool called “The Hunger Vital Sign”. Screening barriers identified in the literature include lack of provider knowledge, comfort, and capacity for effective intervention. Addressing this provider knowledge gap through training is essential for implementing robust and sustainable clinical food insecurity screening practices. • This study aims to evaluate the effect of food insecurity education on providers’ knowledge and awareness of food insecurity and their likelihood to screen and make referrals for at-risk patients, as well as to encourage healthcare providers to foster a culture of food insecurity screening and intervention in their practices. Objectives 1. To determine providers’ knowledge of food insecurity and awareness of referral practices and resources to help patients experiencing food insecurity. 2. To determine if providers’ participation in formal food insecurity training influences their likelihood of incorporating food insecurity screening into their patient interviews. 3. To determine if providers’ action following a positive screen is affected by participating in food insecurity training.https://scholarworks.uvm.edu/comphp_gallery/1285/thumbnail.jp

Krebs von den Lungen 6 (KL-6) as a marker for disease severity and persistent radiological abnormalities following COVID-19 infection at 12 weeks

IntroductionAcute presentations of COVID-19 infection vary, ranging from asymptomatic carriage through to severe clinical manifestations including acute respiratory distress syndrome (ARDS). Longer term sequelae of COVID-19 infection includes lung fibrosis in a proportion of patients. Krebs von den Lungen 6 (KL-6) is a mucin like glycoprotein that has been proposed as a marker of pulmonary epithelial cell injury. We sought to determine whether KL-6 was a marker of 1) the severity of acute COVID-19 infection, or 2) the persistence of symptoms/radiological abnormalities at medium term follow up.MethodsProspective single centre observational study.ResultsConvalescent KL-6 levels were available for 93 patients (male 63%, mean age 55.8 years) who attended an 12-week follow up appointment after being admitted to hospital with COVID-19. For 67 patients a baseline KL-6 result was available for comparison. There was no significant correlations between baseline KL-6 and the admission CXR severity score or clinical severity NEWS score. Furthermore, there was no significant difference in the baseline KL-6 level and an initial requirement for oxygen on admission or the severity of acute infection as measured at 28 days. There was no significant difference in the 12-week KL-6 level and the presence or absence of subjective breathlessness but patients with abnormal CT scans at 12 weeks had significantly higher convalescent KL-6 levels compared to the remainder of the cohort (median 1101 IU/ml vs 409 IU/ml).ConclusionsThe association between high KL-6 levels at 12 weeks and persisting CT abnormalities (GGO/fibrosis), is a finding that requires further exploration. Whether KL-6 may help differentiate those patients with persisting dyspnoea due to complications rather than deconditioning or dysfunctional breathing alone, is an important future research question