Current treatments to counter sleep dysfunction as a pathogenic stimulus of fibromyalgia

Fibromyalgia is characterized by chronic widespread pain, fatigue and nonrestorative sleep. Polysomnography showed reduced short-wave sleep and abnormal alpha rhythms during nonrapid eye movement sleep in patients with fibromyalgia. However, sleep dysfunction might be pathogenic in fibromyalgia since myalgia and fatigue could be induced in healthy individuals by disrupting sleep. Poor sleep quality was a major risk factor for the subsequent development of chronic widespread pain in healthy pain-free individuals. Sleep disruption leads to impairment of the descending pain inhibition pathways. Aside from good sleep, hygiene, exercise can promote sleep. Among currently available pharmacological treatments, evidence suggests amitriptyline and pregabalin can improve sleep in fibromyalgia

Therapeutic targets in rheumatoid arthritis: the interleukin-6 receptor

RA is a chronic, debilitating disease in which articular inflammation and joint destruction are accompanied by systemic manifestations including anaemia, fatigue and osteoporosis. IL-6 is expressed abundantly in the SF of RA patients and is thought to mediate many of the local and systemic effects of this disease. Unlike a number of other cytokines, IL-6 can activate cells through both membrane-bound (IL-6R) and soluble receptors (sIL-6R), thus widening the number of cell types responsive to this cytokine. Indeed, trans-signalling, where IL-6 binds to the sIL-6R, homodimerizes with glycoprotein 130 subunits and induces signal transduction, has been found to play a key role in acute and chronic inflammation. Elevated levels of IL-6 and sIL-6R in the SF of RA patients can increase the risk of joint destruction and, at the joint level, IL-6/sIL-6R can stimulate pannus development through increased VEGF expression and increase bone resorption as a result of osteoclastogenesis. Systemic effects of IL-6, albeit through conventional or trans-signalling, include regulation of acute-phase protein synthesis, as well as hepcidin production and stimulation of the hypothalamo-pituitary-adrenal axis, the latter two actions potentially leading to anaemia and fatigue, respectively. This review aims to provide an insight into the biological effects of IL-6 in RA, examining how IL-6 can induce the articular and systemic effects of this diseas

Therapeutic targets in rheumatoid arthritis: the interleukin-6 receptor

RA is a chronic, debilitating disease in which articular inflammation and joint destruction are accompanied by systemic manifestations including anaemia, fatigue and osteoporosis. IL-6 is expressed abundantly in the SF of RA patients and is thought to mediate many of the local and systemic effects of this disease. Unlike a number of other cytokines, IL-6 can activate cells through both membrane-bound (IL-6R) and soluble receptors (sIL-6R), thus widening the number of cell types responsive to this cytokine. Indeed, trans-signalling, where IL-6 binds to the sIL-6R, homodimerizes with glycoprotein 130 subunits and induces signal transduction, has been found to play a key role in acute and chronic inflammation. Elevated levels of IL-6 and sIL-6R in the SF of RA patients can increase the risk of joint destruction and, at the joint level, IL-6/sIL-6R can stimulate pannus development through increased VEGF expression and increase bone resorption as a result of osteoclastogenesis. Systemic effects of IL-6, albeit through conventional or trans-signalling, include regulation of acute-phase protein synthesis, as well as hepcidin production and stimulation of the hypothalamo-pituitary-adrenal axis, the latter two actions potentially leading to anaemia and fatigue, respectively. This review aims to provide an insight into the biological effects of IL-6 in RA, examining how IL-6 can induce the articular and systemic effects of this diseas

Fatigue in rheumatoid arthritis

This is an editorial and does not contain an abstract

Clinical significance of Janus Kinase inhibitor selectivity

Cytokines are key drivers of inflammation in RA, and anti-cytokine therapy has improved the outcome of RA. Janus Kinases (JAK) are intracellular tyrosine kinases linked to intracellular domains of many cytokine receptors. There are four JAK isoforms: JAK1, JAK2, JAK3 and TYK2. Different cytokine receptor families utilize specific JAK isoforms for signal transduction. Phosphorylation of JAK when cytokine binds to its cognate receptor leads to phosphorylation of other intracellular molecules that eventually leads to gene transcription. Oral JAK inhibitors (JAKi) have been developed as anti-cytokine therapy in RA. Two JAKi, tofacitinib and baricitinib, have been approved recently for the treatment of RA, and many JAKi are currently in development. JAKi inhibit JAK isoforms with different selectivity. This review discusses the efficacy and safety of JAKi in RA, in particular the potential clinical significance of JAKi selectivity

Effect of biologics and targeted synthetic disease-modifying anti-rheumatic drugs on fatigue in rheumatoid arthritis

Fatigue is a common and debilitating symptom in patients with RA. Since 2007, fatigue has been included as one of the core outcome measures in RA. Clinical trials of biologic DMARDs (bDMARDs) and targeted synthetic DMARDs (tsDMARDs) have included fatigue as a secondary endpoint. A Cochrane review in 2016 concluded that the bDMARDs have a moderate effect on improving fatigue in RA. More recent clinical trials of the new biologic agent sarilumab and the Janus kinase inhibitors tofacitinib and baricitinib showed similar benefits. It remains unclear whether the effect of bDMARDs and tsDMARDs on fatigue is mediated by direct effects or through a reduction in inflammation. As fatigue was a secondary endpoint, many analyses did not adjust for potential confounding factors, including pain, mood and anaemia, which is a significant limitation

Neuropathic-like pain in psoriatic arthritis: evidence of abnormal pain processing

Objectives The primary objective was to investigate the prevalence of neuropathic-like pain in patients with psoriatic arthritis (PsA). Secondary outcomes were to investigate whether mood, fatigue, pain, disease severity and fibromyalgia are associated with neuropathic-like pain in PsA patients. Methods PsA patients were assessed for fatigue, mood, pain, disease activity and fibromyalgia using questionnaires. Neuropathic-like pain was assessed by PainDetect. Results Sixty-four patients with PsA were recruited from the Rheumatology Outpatient Department. Of the 64 patients recruited, 26.6% had ‘likely neuropathic pain’ and 21.9% had ‘possible neuropathic-like pain’ according to the PainDetect questionnaire. Patients with ‘likely neuropathic pain’ had higher disease activity, health assessment questionnaire, patient global self-assessment score, tender and swollen joint counts, dactylitis, enthesitis, pain severity and interference with day-to-day activities, fatigue severity and impact, fibromyalgia, anxiety and depression than ‘unlikely neuropathic pain’ patients (p < 0.05). PainDetect score correlated with measures of disease activity, fatigue, depression, anxiety, Widespread Pain Index and Symptom Severity Scale (all p < 0.05). Most patients (71%) with neuropathic-like pain fulfilled American College of Rheumatology 2010 fibromyalgia criteria. Patients with ‘possible neuropathic-like pain’ had scores between patients with ‘likely neuropathic pain’ and ‘unlikely neuropathic pain’. Conclusion Neuropathic-like pain as evidence of abnormal pain processing is common in patients with PsA. It is associated with higher disease activity and fibromyalgia. A significant proportion of patients had ‘possible neuropathic-like’ pain with intermediate disease and symptom score suggesting neuropathic-like pain as evidence of abnormal pain processing is a continuum rather than concurrent fibromyalgia