Type I interferon regulates cytokine-delayed neutrophil apoptosis, reactive oxygen species production and chemokine expression.

Interferons (IFNs) are key regulators of a number of inflammatory conditions in which neutrophils play an important role in pathology, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), where type I IFNs are implicated in disease pathology. However, IFNs are usually generated in vivo together with other cytokines that also have immunoregulatory functions, but such interactions are poorly defined experimentally. We measured the effects of type I (IFN-α) IFN, elevated in both RA and SLE, on the functions of healthy neutrophils incubated in vitro in the absence and presence of proinflammatory cytokines typically elevated in inflammatory diseases [tumour necrosis factor (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF)]. IFN-α alone had no effect on neutrophil apoptosis; however, it abrogated the anti-apoptotic effect of GM-CSF (18 h, P < 0·01). The enhanced stability of the anti-apoptotic protein myeloid cell leukaemia 1 (Mcl-1) and delayed activation of caspase activation normally regulated by GM-CSF were blocked by IFN-α: this effect was mediated, in part, by activation of p38 mitogen-activated protein kinase (MAPK). IFN-α alone also primed reactive oxygen species (ROS) production and maintained the transient priming effect of TNF-α for up to 4 h: it also down-regulated GM-CSF- and TNF-α-activated expression of chemokine (C-X-C motif) ligand (CXCL)1, CXCL2, CXCL3, CXCL8, CCL3 and CCL4 but, in contrast, increased the expression of CXCL10. These novel data identify complex regulatory signalling networks in which type I IFNs profoundly alter the response of neutrophils to inflammatory cytokines. This is likely to have important consequences in vivo and may explain the complexity and heterogeneity of inflammatory diseases such as RA, in which multiple cytokine cascades have been activated.

APPA (apocynin and paeonol) modulates pathological aspects of human neutrophil function, without supressing antimicrobial ability, and inhibits TNFα expression and signalling.

Neutrophils are key players in the pathophysiological process underlying inflammatory conditions not only by release of tissue-damaging cytotoxic enzymes, reactive oxygen species (ROS) but also by secretion of important immunomodulatory chemokines and cytokines. Here, we report the effects of the novel agent APPA, undergoing formal clinical development for treatment of osteoarthritis, and its constituent components, apocynin (AP) and paeonol (PA) on a number of neutrophil functions, including effects on TNFα- expression and signalling. Neutrophils were treated with APPA (10-1000 µg/mL) prior to the measurement of cell functions, including ROS production, chemotaxis, apoptosis and surface receptor expression. Expression levels of several key genes and proteins were measured after incubation with APPA and the chromatin re-modelling agent, R848. APPA did not significantly affect phagocytosis, bacterial killing or expression of surface receptors, while chemotactic migration was affected only at the highest concentrations. However, APPA down-regulated neutrophil degranulation and ROS levels, and decreased the formation of neutrophil extracellular traps. APPA also decreased cytokine-stimulated gene expression, inhibiting both TNFα- and GM-CSF-induced cell signalling. APPA was as effective as infliximab in down-regulating chemokine and IL-6 expression following incubation with R848. Whilst APPA does not interfere with neutrophil host defence against infections, it does inhibit neutrophil degranulation, and cytokine-driven signalling pathways (e.g. autocrine signalling and NF-κB activation), processes that are associated with inflammation. These observations may explain the mechanisms by which APPA exerts anti-inflammatory effects and suggests a potential therapeutic role in inflammatory diseases in which neutrophils and TNFα signalling are important in pathology, such as rheumatoid arthritis.

Janus kinase inhibitors prevent migration of rheumatoid arthritis neutrophils towards interleukin-8, but do not inhibit priming of the respiratory burst or reactive oxygen species production.

Neutrophils play a crucial role in the pathophysiology of rheumatoid arthritis (RA) via the release of reactive oxygen species (ROS), proteases and cytokines. Orally active Janus kinase (JAK) inhibitors (JAKi), e.g. baricitinib and tofacitinib, have high clinical efficacy in RA but are linked with neutropenia and increased infections. Our aim was to determine the effect of JAK inhibition with baricitinib and tofacitinib on healthy control and RA neutrophil lifespan and function. RA (n = 7) and healthy control (n = 7) neutrophils were treated with baricitinib or tofacitinib for 30 min, prior to incubation in the absence or presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) or interferon (IFN)-γ. JAKi prevented GM-CSF- and IFN-γ-induced apoptosis delay in RA and healthy control neutrophils in a dose-dependent manner. Baricitinib decreased the rate of chemotaxis towards interleukin (IL)-8, but not f-Met-Leu-Phe (fMLP) in RA neutrophils. While healthy control neutrophils incubated with GM-CSF became primed to produce ROS in response to stimulation with fMLP and phorbol-12-myristate-12-acetate (PMA), RA neutrophils produced increased levels of ROS without the need for priming. JAKi prevented ROS release from primed healthy control neutrophils in response to fMLP, but had no effect on ROS production by RA neutrophils. Baricitinib reversed GM-CSF priming of ROS production in response to fMLP in healthy control, but not RA, neutrophils. We conclude that incubation with JAKi prevents chemotaxis of RA neutrophils towards IL-8, but does not prevent the production of ROS or increase the level of apoptosis. This may be due to the in-vivo exposure of RA neutrophils to priming agents other than those that activate JAK/signal transducer and activator of transcription (STAT) signalling.

Inflammatory arthritis in HIV positive patients: A practical guide.

BACKGROUND: Musculoskeletal manifestations of the human immunodeficiency virus (HIV) have been described since the outset of the global HIV epidemic. Articular syndromes that have been described in association with HIV include HIV-associated arthropathy, seronegative spondyloarthropathies (SPA) (reactive arthritis, psoriatic arthritis (PsA) and undifferentiated SPA), rheumatoid arthritis (RA) and painful articular syndrome. METHODS: We carried out a computer-assisted search of PubMed for the medical literature from January 1981 to January 2015 using the keywords HIV, acquired immune-deficiency syndrome, rheumatic manifestations, arthritis, spondyloarthropathy, anti-TNF and disease modifying antirheumatic drugs. Only English language literature was included and only studies involving adult human subjects were assessed. RESULTS: There are challenges in the management of inflammatory arthritis in patients who are HIV-positive, including difficulties in the assessment of disease activity and limited information on the safety of immunosuppressive drugs in these individuals. CONCLUSIONS: This review focuses on the clinical characteristics of the inflammatory articular syndromes that have been described in association with HIV infection and discusses the therapeutic options for these patients.

Cutaneous immunopathology of long-standing complex regional pain syndrome.

BACKGROUND: Both increased mast cells numbers and raised immune mediator concentrations indicate immune activation in the affected skin of patients with early complex regional pain syndrome (CRPS), but little is known about regional immune cell involvement in late-stage CRPS. The aim of the current study was to determine skin immune cell populations in long-standing CRPS. METHODS: Using 6-mm skin punch biopsies from CRPS-affected and non-affected tissues, and a combination of chemical and immunofluorescence staining, we examined the density and function of key cell populations including mast cells, epidermal Langerhans cells (LCs) and tissue resident T-cells. RESULTS: We found no significant differences in either overall immune cell infiltrates, or mast cell density between CRPS-affected and non-affected sub-epidermal tissue sections, contrasting recent findings in early CRPS by other groups. However, CD1a(+) LC densities in the epidermal layer were significantly decreased in affected compared to non-affected CRPS limbs (p < 0.01). T-cell clones isolated from CRPS-affected sub-epidermal tissues displayed a trend towards increased IL-13 production in ELISPOT assays when compared to T-cells isolated from non-affected areas, suggesting a Th2 bias. CONCLUSIONS: Immune cell abnormalities are maintained in late-stage CRPS disease as manifest by changes in epidermal LC density and tissue resident T-cell phenotype.

Rituximab versus an alternative TNF inhibitor in patients with rheumatoid arthritis who failed to respond to a single previous TNF inhibitor: SWITCH-RA, a global, observational, comparative effectiveness study.

OBJECTIVES: To compare the effectiveness of rituximab versus an alternative tumour necrosis factor (TNF) inhibitor (TNFi) in patients with rheumatoid arthritis (RA) with an inadequate response to one previous TNFi. METHODS: SWITCH-RA was a prospective, global, observational, real-life study. Patients non-responsive or intolerant to a single TNFi were enrolled ≤4 weeks after starting rituximab or a second TNFi. Primary end point: change in Disease Activity Score in 28 joints excluding patient's global health component (DAS28-3)-erythrocyte sedimentation rate (ESR) over 6 months. RESULTS: 604 patients received rituximab, and 507 an alternative TNFi as second biological therapy. Reasons for discontinuing the first TNFi were inefficacy (n=827), intolerance (n=263) and other (n=21). A total of 728 patients were available for primary end point analysis (rituximab n=405; TNFi n=323). Baseline mean (SD) DAS28-3-ESR was higher in the rituximab than the TNFi group: 5.2 (1.2) vs 4.8 (1.3); p<0.0001. Least squares mean (SE) change in DAS28-3-ESR at 6 months was significantly greater in rituximab than TNFi patients: -1.5 (0.2) vs -1.1 (0.2); p=0.007. The difference remained significant among patients discontinuing the initial TNFi because of inefficacy (-1.7 vs -1.3; p=0.017) but not intolerance (-0.7 vs -0.7; p=0.894). Seropositive patients showed significantly greater improvements in DAS28-3-ESR with rituximab than with TNFi (-1.6 (0.3) vs -1.2 (0.3); p=0.011), particularly those switching because of inefficacy (-1.9 (0.3) vs -1.5 (0.4); p=0.021). The overall incidence of adverse events was similar between the rituximab and TNFi groups. CONCLUSIONS: These real-life data indicate that, after discontinuation of an initial TNFi, switching to rituximab is associated with significantly improved clinical effectiveness compared with switching to a second TNFi. This difference was particularly evident in seropositive patients and in those switched because of inefficacy.

Oxygen and pH-sensitivity of human osteoarthritic chondrocytes in 3-D alginate bead culture system.

OBJECTIVE: To identify the effect of alterations in physical parameters such as oxygen and pH on processes associated with cellular redox balance in osteoarthritic chondrocytes. METHOD: Human osteoarthritic chondrocytes (HOAC) were isolated from total knee arthroplasty samples and cultured in 3-D alginate beads in four different oxygen tensions (<1%, 2%, 5% and 21% O2), at pH 7.2 and 6.2 and in the presence or absence of 10 ng/ml, interleukin-1ß (IL-1ß). Cell viability, media glycosaminoglycan (GAG) levels, media nitrate/nitrate levels, active matrix metalloproteinase (MMP)-13 and intracellular adenosine triphosphate (ATPi) were measured over a 96-h time course. Intracellular reactive oxygen species (ROS), mitochondrial membrane potential, intracellular pH and reduced/oxidised glutathione (GSH/GSSG) were additionally measured after 48-h incubation under these experimental conditions. RESULTS: Hypoxia (2% O2) and anoxia (<1% O2), acidosis (pH 6.2) and 10 ng/ml IL-1ß reduced HOAC cell viability and increased GAG media levels. Acidosis and IL-1ß increased nitrite/nitrate release, but increases were moderate at 2% O2 and significantly reduced at <1% O2. ATPi was significantly reduced following hypoxia and anoxia and acidosis. At 48 h cellular ROS levels were increased by acidosis and IL-1ß but reduced in hypoxia and anoxia. Mitochondrial membrane potential was reduced in low oxygen, acidosis and IL-1ß. Anoxia also resulted in intracellular acidosis. GSH/GSSG ratio was reduced in low oxygen conditions, acidosis and IL-1ß. CONCLUSIONS: This study shows that oxygen and pH affect elements of the redox system in HOAC including cellular anti-oxidants, mitochondrial membrane potential and ROS levels.

Patient-reported outcomes improve with etanercept plus methotrexate in active early rheumatoid arthritis and the improvement is strongly associated with remission: the COMET trial.

OBJECTIVES: To compare the effects of etanercept (ETN) 50 mg once weekly plus methotrexate (MTX) versus MTX alone on patient-reported outcomes (PROs) and the relationship between remission and PRO improvement. METHODS: In this double-blind, randomised clinical trial (COMET), PROs included: the Health Assessment Questionnaire (HAQ), EuroQoL health status, fatigue and pain visual analogue scales, Hospital Anxiety and Depression Scale, and Medical Outcomes Short-Form-36. Mean changes from baseline were analysed by analysis of covariance using the last observation carried forward method. Results from week 52 are presented. RESULTS: Most PROs demonstrated significantly greater improvements with ETN+MTX than MTX alone, including physical functioning, pain, fatigue and overall health status. A significantly greater improvement in HAQ score was observed in the ETN+MTX than the MTX group (-1.02 vs -0.72; p<0.001) and a greater proportion reached the minimal clinically important difference of 0.22 (88% vs 78%; p<0.006). The relationship between PRO score and clinical status indicated that improvement was greatest among patients achieving remission. CONCLUSIONS: Early treatment with ETN+MTX leads to significantly greater improvements in multiple dimensions of PROs than MTX alone. The close relationship between disease activity and PRO improvement suggests that early treatment, with remission as a goal, should maximise the chance of restoring normal functioning and HRQoL.

Ear, nose and throat manifestations of Behçet's disease: a review.

OBJECTIVE: To review Behçet's disease and to describe its clinical features in the head, neck and upper respiratory tract. METHOD: A literature review was undertaken, following a Medline search of publications over a 30-year period, and utilising the expert knowledge of one of the authors (RJM) with a specialist interest in Behçet's disease. RESULTS: Twenty-seven articles with ENT relevance were obtained. Otorhinolaryngological manifestations included symptoms and signs in the mouth, nose, sinus, larynx and ear. CONCLUSION: Behçet's disease is usually considered to be a condition affecting the oral cavity, eyes and genitals. This article shows that most patients will also exhibit other ENT symptoms, hearing loss in particular. Indeed, Behçet's disease may present with features other than the classic triad of symptoms. Raised awareness of the clinical features within the head and neck region will hopefully enable early diagnosis and treatment of this potentially serious condition.

CDP-870 (certolizumab) in rheumatoid arthritis.

The development of biological anti-TNF-alpha therapy has revolutionised the treatment of rheumatoid arthritis and other inflammatory diseases, and has identified a worldwide market for expensive yet effective therapies for chronic diseases. Certolizumab (CDP-870) is a new agent that employs a novel strategy to neutralise TNF-alpha--namely the prokaryotic expression of TNF-alpha-specific Fab antibody fragments, coupled to polyethylene glycol--to produce a drug that is potentially less expensive to manufacture than other anti-TNF-alpha agents and which may be administered by subcutaneous injection once a month. The background to the ongoing development of this new agent and its clinical effects are discussed in this article.

Congenital heart block associated with undiagnosed maternal Primary Sjögren's Syndrome -- a case report and discussion.

Congenital heart block (CHB) has been linked with Sjögren's Syndrome. This paper reports a case of previously undiagnosed maternal Primary Sjögren's Syndrome (1 degrees SS) that was only discovered following the birth of the patient's first child with CHB. The possible pathophysiological mechanisms underlying CHB associated with 1 degrees SS are discussed.

Regulation of neutrophil apoptosis by Mcl-1.

Neutrophils rapidly undergo spontaneous apoptosis, but this process can be considerably delayed by exposure to a variety of agents such as pro-inflammatory cytokines. The anti-apoptotic protein of the Bcl-2 family, Mcl-1, plays a key role in the regulation of neutrophil apoptosis. The protein has some unusual properties compared with other family members, including an extremely high turnover rate. Many factors, such as cytokines and local oxygen concentrations, can regulate cellular levels of Mcl-1 via transcription and post-transcriptional modification, control the survival time of neutrophils within tissues and thereby influence the inflammatory response.

Steroids, non-steroidal anti-inflammatory drugs, and sigmoid diverticular abscess perforation in rheumatic conditions.

BACKGROUND: Corticosteroids and non-steroidal anti-inflammatory drugs are widely used for the treatment of rheumatic conditions, but their gastrointestinal damage significantly limits their use. Sigmoid diverticular abscess perforation (SDAP) is a very serious complication of diverticular disease. OBJECTIVE: To determine the aetiology of large bowel SDAP in rheumatic conditions. METHODS: 64 patients with SPAD and 320 controls from a similar geographical area and of similar socioeconomic status were studied. RESULTS: The results showed that independently of rheumatic diagnosis corticosteroid treatment is strongly associated with SDAP (OR 31.9 (95% CI 6.4 to 159.2; p<0.001), and non-steroidal anti-inflammatory drugs only weakly associated (OR 1.8 (95% CI 0.96 to 3.4); p = 0.069). A rheumatic diagnosis is also strongly associated with the development of SDAP (OR 3.5 (95% CI 1.9 to 6.7); p<0.001). CONCLUSIONS: SDAP has serious implications for patients and consumes many healthcare resources. Patients and physicians should be warned of this potential complication.