Circadian rhythms and rheumatoid arthritis

Circadian disturbances by altering the light-dark cycle negatively affects hematopoietic function of bone marrow in mice

Circadian rhythms in metabolically active tissues are crucial for maintaining physical health. Circadian disturbance (CD) can cause various health issues, such as metabolic abnormalities and immune and cognitive dysfunctions. However, studies on the role of CD in immune cell development and differentiation, as well as the rhythmic expression of the core clock genes and their altered expression under CD, remain unclear. Therefore, we exposed C57bl/6j mice to repeated reversed light-dark cycles for 90 days to research the effects of CD on bone marrow (BM) hematopoietic function. We also researched the effects of CD on endogenous circadian rhythms, temporally dependent expression in peripheral blood and myeloid leukocytes, environmental homeostasis within BM, and circadian oscillations of hematopoietic-extrinsic cues. Our results confirmed that when the light and dark cycles around mice were frequently reversed, the circadian rhythmic expression of the two main circadian rhythm markers, the hypothalamic clock gene, and serum melatonin, was disturbed, indicating that the body was in a state of endogenous CD. Furthermore, CD altered the temporally dependent expression of peripheral blood and BM leukocytes and destroyed environmental homeostasis within the BM as well as circadian oscillations of hematopoietic-extrinsic cues, which may negatively affect BM hematopoiesis in mice. Collectively, these results demonstrate that circadian rhythms are vital for maintaining health and suggest that the association between CD and hematopoietic dysfunction warrants further investigation.

How does circadian rhythm affect postoperative pain after pediatric acute appendicitis surgery?

BACKGROUND

This study aimed to evaluate the relationship between postoperative pain and circadian rhythm after pediatric acute appendicitis surgery.

METHODS

Two hundred patients, aged 6-18 years, undergoing acute appendicitis surgery were included in this prospective observational study. The patients were divided into four groups according to the time they underwent surgery: the night group, 01:01-07:00; morning group, 07:01-13:00; afternoon group, 13:01-19:00; and evening group, 19:01-01:00. Intraoperative and postoperative vital signs, postoperative 24-h Wong-Baker Faces Pain Rating Scale (FACEs) scores, and the amount of analgesic required were recorded.

RESULTS

A total of 186 patients were analyzed in the study. There was no statistically significant difference in the demographic characteristics of the patient groups. Additionally, no differences were observed in intraoperative and postoperative vital signs among the four groups. However, patients in the night group had significantly higher FACEs values than those in the other groups at each time point (1st, 3rd, 6th, and 12th h) up to 12 h (P = 0.007, P = 0.023, P = 0.048, and P = 0.003, respectively). The amount of analgesic required in the night group was statistically higher than in the other groups until 12 h (P = 0.002, P < 0.001, P = 0.002, and P = 0.004, respectively).

CONCLUSIONS

A relationship was found between acute appendicitis operations performed at night (01:01 to 07:00) under general anesthesia and circadian rhythm in children. We believe that considering circadian time in the relief of postoperative pain would be beneficial.

An engineered glove to follow finger function in rheumatoid arthritis: an observational prospective study

The engineered Hand Test System (HTS) glove has shown high reliability in assessing the baseline functional status of rheumatoid arthritis (RA) hand. Starting from this achievement, the aim of the present observational prospective study was to assess the functionality of the single fingers of rheumatoid hand at follow-up. Eighty RA patients performed HTS glove tests at baseline and among these fifty-six patients were re-tested after 7 months. The HTS glove parameters [Touch Duration (TD), Movement Rate (MR), Inter Tapping Interval (ITI)] were correlated with disease activity and disability clinimetric indexes [Disease Activity Score 28 joint count-C-reactive protein (DAS28-CRP), Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), Health Assessment Questionnaire-Disability Index (HAQ-DI), grip strength, visual analogue scale of pain (VAS), patient global assessment (PGA)], and with laboratory values. HTS glove parameters (TD, ITI, and MR) showed statistically significant correlations with clinimetric and clinical indexes at both time points (p < 0.05). During follow-up, a statistically significant variation of all HTS glove parameters for the fingers that have performed both the worst or best HTS test at baseline was detected (p < 0.05), while the mean HTS glove parameter values by considering all fingers did not show a statistically significant variation over time, as well as the traditional clinimetric indexes. Besides the objective role in assessing the RA hand function by integrating the traditional clinimetric indexes, the HTS glove seems a useful tool for evaluating worst or best finger function during time by measuring the movement speed.

Diurnal production of cortisol and prediction of treatment response in rheumatoid arthritis: a 6-month, real-life prospective cohort study

OBJECTIVES

A reduced adrenal reserve-associated cortisol production relative to the enhanced needs of chronic inflammation (disproportion principle) has been observed in rheumatoid arthritis (RA). We examined the possible clinical value of diurnal cortisol measurements in active RA on treatment response prediction.

METHODS

Diurnal cortisol production (measured at: 08-12:00/18:00-22:00) was assessed by electrochemiluminescence immunoassay in 28 consecutive patients with moderately/highly active RA, as well as 3 and 6 months after treatment initiation or/escalation. Twenty-eight COVID-19 patients and 28 age-matched healthy individuals (HC) served as controls.

RESULTS

Saliva diurnal cortisol production in patients with RA was similar to that of HC, despite 12-fold higher serum C reactive protein (CRP) levels, and lower than COVID-19 patients (area under the curve: RA: 87.0±37.6 vs COVID-19: 146.7±14.3, p<0.001), having similarly high CRP. Moreover, a disturbed circadian cortisol rhythm at baseline was evident in 15 of 28 of patients with RA vs 4 of 28 and 20 of 28 of HC and COVID-19 patients, respectively. Treatment-induced minimal disease activity (MDA) at 6 months was achieved by 16 of 28 patients. Despite comparable demographics and clinical characteristics at baseline, non-MDA patients had lower baseline morning cortisol and higher adrenocorticotropic hormone (ACTH) levels compared with patients on MDA (cortisol: 10.9±4.0 vs 18.4±8.2 nmol/L, respectively, p=0.005 and ACTH: 4.8±3.3 vs 2.4±0.4 pmol/L, respectively, p=0.047). Baseline morning cortisol <13.9 nmol/L predicted non-MDA at 6 months (75% sensitivity, 92% specificity, p=0.006). Prospective measurements revealed that individualised diurnal cortisol production remained largely unchanged from baseline to 3 and 6 months.

CONCLUSIONS

An impaired adrenal reserve is present in patients with RA. Further studies to confirm that assessment of diurnal cortisol production may be useful in guiding treatment decisions and/or predicting treatment response in RA are warranted.

TRIAL REGISTRATION NUMBER

NCT05671627.

Personalized therapy in rheumatoid arthritis (PETRA): a protocol for a randomized controlled trial to test the effect of a psychological intervention in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects cartilage and bone. Psychological stress can both trigger disease exacerbation and result from disease activity. As standard pharmacological interventions alone have limited success in treating RA, a more comprehensive biopsychosocial approach to treatment has been recommended. In this prospective randomized controlled trial (RCT), a psychotherapeutically guided, group-based intervention program will be conducted with RA patients over a period of 9 months. This program combines a dynamic-interactional model with disorder-specific coping-oriented perspectives to improve patients' social, emotional, and problem-solving competencies as well as stress system functional status. The enrolment of 440 patients, randomly allocated to either an intervention (n = 220) or control group (n = 220), is planned. To evaluate the intervention effect, various indicators of RA disease activity, stress system activity, and psychological condition will be assessed through sets of standardized questionnaires and biochemical analyses of blood and saliva samples. Moreover, healthcare-related costs for each patient will be obtained using routine health insurance data. Outcome variables will be measured in all patients at regular intervals prior to intervention (baseline), during the 9-month intervention (five time points), and during a 9-month follow-up phase (three time points), allowing the comprehensive analysis of within- and between-subject effects, i.e. trajectories of the target variables in the intervention and control groups. In addition, to investigate the intervention effects on real-life stress system functioning in RA, 10 integrative single-case studies (n = 5 from the intervention group, n = 5 from the control group) will be conducted. In each study, once before and after the 9-month intervention, urine samples will be collected, and patients will fill out questionnaires for approximately 1 month at 12-h intervals. Moreover, weekly in-depth interviews will be conducted with patients to determine their previous week's emotionally positive and negative incidents. Using time series analysis, it is then possible to investigate whether and how stress system function in these RA patients has improved from the applied intervention. By using both an investigational macro- and microperspective, this project aims to evaluate a psychological intervention in the routine care of individuals with RA.Trial registration German Clinical Trials Register DRKS00028144. Registered on 1 March 2022.

Unleashing the pathological imprinting of cancer in autoimmunity: Is ZEB1 the answer?

The intriguing scientific relationship between autoimmunity and cancer immunology have been traditionally indulged to throw spotlight on novel pathological targets. Understandably, these "slowly killing" diseases are on the opposite ends of the immune spectrum. However, the immune regulatory mechanisms between autoimmunity and cancer are not always contradictory and sometimes mirror each other based on disease stage, location, and timepoint. Moreover, the blockade of immune checkpoint molecules or signalling pathways that unleashes the immune response against cancer is being leveraged to preserve self-tolerance and treat many autoimmune disorders. Therefore, understanding the common crucial factors involved in cancer is of paramount importance to paint the autoimmune disease spectrum and validate novel drug candidates. In the current review, we will broadly describe how ZEB1, or Zinc-finger E-box Binding Homeobox 1, reinforces immune exhaustion in cancer or contributes to loss of self-tolerance in auto-immune conditions. We made an effort to exchange information about the molecular pathways and pathological responses (immune regulation, cell proliferation, senescence, autophagy, hypoxia, and circadian rhythm) that can be regulated by ZEB1 in the context of autoimmunity. This will help untwine the intricate and closely postured pathogenesis of ZEB1, that is less explored from the perspective of autoimmunity than its counterpart, cancer. This review will further consider several approaches for targeting ZEB1 in autoimmunity.

Clock gene Per1 regulates rat temporomandibular osteoarthritis through NF-κB pathway: an in vitro and in vivo study

PURPOSE

Temporomandibular joint osteoarthritis (TMJOA) is a common disease that negatively affects the life quality of human beings. Circadian rhythm acts an important role in life activities. However, whether the clock genes are rhythmic expressed in mandibular condylar chondrocytes, or the clock genes have an effect on the progression of TMJOA remains unknown. In this study, we aim to explore expression of clock genes and regulatory mechanism of TMJOA in rat mandibular condylar chondrocytes.

METHODS

After synchronized by dexamethasone, the expression of core clock genes Per1, Per2, Clock, Cry1, Cry2 and Bmal1 and cartilage matrix degrading factor gene Mmp13 were analyzed in mandibular condylar chondrocytes every 4 h with RT-qPCR. The mandibular condylar chondrocytes were stimulated with IL-1β, and expression of Per1, Mmp13, P65 and p-P65 was assessed by RT-qPCR and Western blot. Sh-Per1 lentivirus was used to assess the effect of clock gene Per1 in IL-1β-induced chondrocytes, and expression of Mmp13, P65 and p-P65 was measured. After establishing a rat TMJOA model using unilateral anterior crossbite (UAC), micro-CT, H & E, Alcian Blue & Nuclear Fast Red and Safranin O & Fast Green, cartilage thickness was utilized to assess the damage of cartilage and subchondral bone. Immunohistochemistry of PER1, MMP13 and P65 was performed in condylar sections.

RESULTS

All core clock genes and Mmp13 were rhythmically expressed. And Mmp13 expression curve was closed in phase and amplitude with Per1. After stimulation with IL-1β, the expression of MMP13, PER1 and P65 and ratio of p-P65/P65 increased in condylar chondrocytes. After Per1 was down-regulated in condylar chondrocytes, the expression of MMP13 and P65 and ratio of p-P65/P65 decreased. Compared with the condyles of Sham group, the bony parameters of UAC group were significantly worse. The thickness of cartilage in UAC group significantly reduced. The modified Mankin scores and the expression of PER1, MMP13 and P65 in cartilage of UAC group significantly increased compared with Sham group.

CONCLUSION

Core clock genes and Mmp13 are rhythmic expressed in rat mandibular condylar chondrocytes. PER1 can regulate the expression of MMP13 through NF-κB pathway in IL-1β-induced mandibular condylar chondrocytes.

Detecting and exploiting the circadian clock in rheumatoid arthritis

Over the past four decades, research on 24-h rhythms has yielded numerous remarkable findings, revealing their genetic, molecular, and physiological significance for immunity and various diseases. Thus, circadian rhythms are of fundamental importance to mammals, as their disruption and misalignment have been associated with many diseases and the abnormal functioning of many physiological processes. In this article, we provide a brief overview of the molecular regulation of 24-h rhythms, their importance for immunity, the deleterious effects of misalignment, the link between such pathological rhythms and rheumatoid arthritis (RA), and the potential exploitation of chronobiological rhythms for the chronotherapy of inflammatory autoimmune diseases, using RA as an example.

The dichotomy of glucocorticosteroid treatment in immune-inflammatory rheumatic diseases: an evidence-based perspective and insights from clinical practice

Objectives

Glucocorticosteroids (GCs) are the most used anti-inflammatory and immunosuppressive drugs due to their effectiveness in managing pain and disease modification in many immune-inflammatory rheumatic diseases (IRDs). However, their use is limited because of adverse effects (AEs).

Material and methods

The authors analyzed recent studies, including randomized controlled trials (RCTs), observational, translational studies and systematic reviews, providing an in-depth viewpoint on the benefits and drawbacks of GC use in rheumatology.

Results

Glucocorticosteroids are essential in managing life-threatening autoimmune diseases and a cornerstone in many IRDs given their swift onset of action, necessary in flares. Several RCTs and meta-analyses have demonstrated that when administered over a long time and on a low-dose basis, GC can slow the radiographic progression in early rheumatoid arthritis (RA) patients by at least 50%, satisfying the conventional definition of a disease-modifying anti-rheumatic drug (DMARD). In the context of RA treatment, the use of modified-release prednisone formulations at night may offer the option of respecting circadian rhythms of both inflammatory response and HPA activation, thereby enabling low-dose GC administration to mitigate nocturnal inflammation and prolonged morning fatigue and joint stiffness. Long-term GC use should be individualized based on patient characteristics and minimized due to their potential AEs. Their chronic use, especially at medium/high dosages, might cause irreversible organ damage due to the burden of metabolic systemic effects and increased risk of infections. Many international guidelines recommend tapering/withdrawal of GCs in sustained remission. Treat-to-target (T2T) strategies are critical in setting targets for disease activity and reducing/discontinuing GCs once control is achieved.

Conclusions

Glucocorticosteroids' use in treating IRDs should be judicious, focused on minimizing use, tapering and discontinuing treatment, when possible, to improve long-term safety. Glucocorticosteroids remain part of many therapeutic regimens, particularly at low doses, and elderly RA patients, especially with associated chronic comorbidities, may benefit from long-term low-dose GC treatment. A personalized GC therapy is essential for optimal long-term outcomes.

Circadian rhythm in systemic autoimmune conditions: Potential of chrono-immunology in clinical practice: A narrative review

The circadian rhythm (CR) is a fundamental biological process regulated by the Earth's rotation and solar cycles. It plays a critical role in various bodily functions, and its dysregulation can have systemic effects. These effects impact metabolism, redox homeostasis, cell cycle regulation, gut microbiota, cognition, and immune response. Immune mediators, cycle proteins, and hormones exhibit circadian oscillations, supporting optimal immune function and defence against pathogens. Sleep deprivation and disruptions challenge the regulatory mechanisms, making immune responses vulnerable. Altered CR pathways have been implicated in diseases such as diabetes, neurological conditions, and systemic autoimmune diseases (SADs). SADs involve abnormal immune responses to self-antigens, with genetic and environmental factors disrupting self-tolerance and contributing to conditions like Systemic Lupus Erythematosus, Rheumatoid Arthritis, and Inflammatory Myositis. Dysregulated CR may lead to increased production of pro-inflammatory cytokines, contributing to the systemic responses observed in SADs. Sleep disturbances significantly impact the quality of life of patients with SADs; however, they are often overlooked. The relationship between sleep and autoimmune conditions, whether causal or consequential to CR dysregulation, remains unclear. Chrono-immunology investigates the role of CR in immunity, offering potential for targeted therapies in autoimmune conditions. This paper provides an overview of the connections between sleep and autoimmune conditions, highlighting the importance of recognizing sleep disturbances in SADs and the need for further research into the complex relationship between the CR and autoimmune diseases.

Circadian Modulation of the Antioxidant Effect of Grape Consumption: A Randomized Controlled Trial

Grape consumption acts on the immune system to produce antioxidant and anti-inflammatory effects. Since immune activity demonstrates circadian rhythmicity, with peak activity occurring during waking hours, the timing of grape intake may influence the magnitude of its antioxidant effect. This study followed a 2 × 2 factorial randomized, controlled design wherein healthy men and women (n = 32) consumed either a grape or placebo drink with a high-fat meal in the morning or evening. Urine was collected for measurements of biomarkers of oxidative stress and grape metabolites at baseline and post-meal at hour 1 and hours 1-6. F-2 isoprostane levels showed main effects of time period (baseline < hour 1 < hours 1-6, p < 0.0001), time (a.m. > p.m., p = 0.008) and treatment (placebo > grape, p = 0.05). Total F2-isoprostane excretion expressed as % baseline was higher in the a.m. vs. p.m. (p = 0.004) and in the a.m. placebo vs. all other groups (p < 0.05). Tartaric acid and resveratrol excretion levels were higher in the grape vs. placebo group (p < 0.05) but were not correlated with F-2 isoprostane levels. The findings support a protective effect of grape consumption against morning sensitivity to oxidative stress.

Circadian Regulation of Macrophages and Osteoclasts in Rheumatoid Arthritis

Rheumatoid arthritis (RA) represents one of the best examples of circadian fluctuations in disease severity. Patients with RA experience stiffness, pain, and swelling in afflicted joints in the early morning, which tends to become milder toward the afternoon. This has been primarily explained by the higher blood levels of pro-inflammatory hormones and cytokines, such as melatonin, TNFα, IL-1, and IL-6, in the early morning than in the afternoon as well as insufficient levels of anti-inflammatory cortisol, which rises later in the morning. Clinical importance of the circadian regulation of RA symptoms has been demonstrated by the effectiveness of time-of-day-dependent delivery of therapeutic agents in chronotherapy. The primary inflammatory site in RA is the synovium, where increased macrophages, T cells, and synovial fibroblasts play central roles by secreting pro-inflammatory cytokines, chemokines, and enzymes to stimulate each other, additional immune cells, and osteoclasts, ultimately leading to cartilage and bone erosion. Among these central players, macrophages have been one of the prime targets for the study of the link between circadian rhythms and inflammatory activities. Gene knockout experiments of various core circadian regulators have established that disruption of any core circadian regulators results in hyper- or hypoactivation of inflammatory responses by macrophages when challenged by lipopolysaccharide and bacteria. Although these stimulations are not directly linked to RA etiology, these findings serve as a foundation for further study by providing proof of principle. On the other hand, circadian regulation of osteoclasts, downstream effectors of macrophages, remain under-explored. Nonetheless, circadian expression of the inducers of osteoclastogenesis, such as TNFα, IL-1, and IL-6, as well as the knockout phenotypes of circadian regulators in osteoclasts suggest the significance of the circadian control of osteoclast activity in the pathogenesis of RA. More detailed mechanistic understanding of the circadian regulation of macrophages and osteoclasts in the afflicted joints could add novel local therapeutic options for RA.

Understanding the role of chronopharmacology for drug optimization: what do we know?

INTRODUCTION

Circadian rhythm influences the pharmacokinetics and pharmacodynamics of a number of drugs and affects their therapeutic efficacy and toxicity depending on the time of day they are administered. Chronopharmacology is a method for incorporating knowledge about circadian rhythm into pharmacotherapy. Chronotherapy, which is the clinical application of chronopharmacology, is particularly relevant when the risk and/or severity of symptoms of a disease change in a predictable manner over time. Chronotherapy has potential benefits in the treatment of many diseases.

AREAS COVERED

Although a considerable amount of knowledge about chronopharmacology and chronotherapy has been accumulated, its therapeutic application in clinical practice remains limited in terms of therapy optimization. Resolution of these issues will improve our ability to deliver adequate drug treatment.

EXPERT OPINION

We propose four approaches for promoting chronotherapy-based drug treatment in clinical practice: targeting drug development and regulatory authorities; education about chronotherapy; drug information for both health professionals and consumers; and a chronotherapy network.

Are We Ready to Implement Circadian Hygiene Interventions and Programs?

Circadian hygiene, a concept not to be confused with the notion of public or social hygiene, should be discussed among experts and society. Light-dark cycles and other possible synchronizers of the human circadian timing system affect ways of life, including sleeping, eating, working and physical activity. Some of these behaviors have also been investigated individually as synchronizers (e.g., eating times). Therefore, the knowledge held today about circadian rhythms, and their implications for health, allows future perspectives in this field to be mapped. The present article summarizes the latest knowledge on factors influencing circadian rhythms to discuss a perspective for the future of health promotion based on circadian hygiene. However, it is important to highlight that circadian hygiene is the product of an imbrication of individual and societal involvement. First, it is important to adopt practices and devise public health policies in line with circadian hygiene. Second, individual healthy habits require internal rhythms to be examined. Last, the research agenda on circadian hygiene can be developed on a public as well as individual level, raising the question as to how much society is willing to embrace this change.

The interrelationship between inflammatory cytokines and skeletal muscle decay from the viewpoint of circadian rhythms

Circadian rhythms affect a variety of physiological processes. Disruption of circadian rhythms causes many diseases, most of which are associated with inflammation. Disruption of circadian rhythms has a detrimental impact on the function of immune system. It is common to find that circulatory LPS are increased. LPS induces immune cells to produce inflammatory cytokines. Inflammatory cytokines play a role in skeletal muscle decay. Rev-erbβ has been identified as a critical regulator of circadian rhythms and a factor in inflammation. Another effect of disruption is a concomitant disturbance of glucose-insulin metabolism, which skeletal muscle likely contributes to considering it is a key metabolic tissue. Disruption of circadian rhythms is also related to obesity. Obesity can cause an increase expression of inflammatory cytokines. Maybe obesity with skeletal muscle decay is one of major characteristics. Future studies are needed to obtain a comprehensive understanding of inflammatory cytokines and skeletal muscle decay from the viewpoint of circadian rhythms.

Identifying hub circadian rhythm biomarkers and immune cell infiltration in rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease with symptoms characterized by typical circadian rhythmic changes. This study aimed to identify the hub circadian rhythm genes (CRGs) in RA and explore their association with immune cell infiltration and pathogenesis of RA.

Methods

The differentially expressed CRGs (DECRGs) between RA and normal control samples were screened from Datasets GSE12021 and GSE55235. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis were used to explore the potential functional mechanisms of DECRGs in RA. Weighted Gene Co-expression Network Analysis and Least Absolute Shrinkage and Selection Operator regression analysis were performed to identify hub CRGs of RA. CIBERSORT was conducted to compare the infiltration level of immune cells in RA and control synovial tissue and their relationship with hub genes. In addition, the diagnostic value of hub biomarkers was evaluated by the area under the receiver operator characteristic curve. Further, a nomogram prediction model was constructed and its significance for clinical decision-making was evaluated.

Results

The green module was identified as the hub module associated with RA. Four hub CRGs (EGR1, FOSL2, GADD45B, and NFIL3) were identified and showed that they had the highest specificity and sensitivity for RA diagnosis, respectively. The expression levels and diagnostic values of these genes were externally validated in the dataset GSE55457. A nomogram prediction model based on the four hub CRGs was constructed and proved to have a certain clinical decision value. Additionally, the correlation analysis of immune cells with hub genes showed that all hub genes were significantly positively correlated with activated mast cells, resting memory CD4+ T cells, and monocytes. Whereas, all hub genes were negatively correlated with plasma cells, CD8+ T cells, and activated memory CD4+ T cells. Meanwhile, FOSL2 and GADD45B were negatively correlated with Tfh cells.

Conclusion

Four hub CRGs were identified and showed excellent diagnostic value for RA. These genes may be involved in the pathological process of RA by disrupting the rhythmic oscillations of cytokines through immune-related pathways and could be considered molecular targets for future chronotherapy against RA.

Metabolic Profiling of Serum for Osteoarthritis Biomarkers

Osteoarthritis is a prevalent aging disease in the world, and in recent years it has shown a trend toward younger age, which is becoming a major health problem in the world and seriously endangers the health of the elderly. However, the etiology and pathogenesis of osteoarthritis are still unclear, causing great trouble for treatment. To screen out candidate biomarkers that could be used for the identification of osteoarthritis and explore the pathogenesis of osteoarthritis, we performed an untargeted metabolomics analysis of nine New Zealand rabbit serum samples by LC-MS/MS, including three normal serum samples (control group) and six osteoarthritis serum samples (case group). Finally, 44 differential metabolites were identified, and the ROC analysis results indicated that a total of 36 differential metabolites could be used as candidate biomarkers. Further metabolic pathway enrichment analysis was performed on these differential metabolites, and we found that a total of 17 metabolic pathways were affected, which may provide directions for the study of osteoarthritis mechanisms.

Cell Surface Transporters and Novel Drug Developments

Despite the numerous scientific and technological advances made within the last decade the attrition rates for new drug discovery remain as high as 95% for anticancer drugs. Recent drug development has been in part guided by Lipinski’s Rule of 5 (Ro5) even though many approved drugs do not comply to these rules. With Covid-19 vaccine development strategy dramatically accelerating drug development perhaps it is timely to question the generic drug development process itself to find a more efficient, cost effective, and successful approach. It is widely believed that drugs permeate cells via two methods: phospholipid bilayer diffusion and carrier mediated transporters. However, emerging evidence suggests that carrier mediated transport may be the primary mechanism of drug uptake and not diffusion as long believed. Computational biology increasingly assists drug design to achieve desirable absorption, distribution, metabolism, elimination and toxicity (ADMET) properties. Perfecting drug entry into target cells as a prerequisite to intracellular drug action is a logical and compelling route and is expected to reduce drug attrition rates, particularly gaining favour amongst chronic lifelong therapeutics. Novel drug development is rapidly expanding from the utilisation of beyond the rule of five (bRo5) to pulsatile drug delivery systems and fragment based drug design. Utilising transporters as drug targets and advocating bRo5 molecules may be the solution to increasing drug specificity, reducing dosage and toxicity and thus revolutionising drug development. This review explores the development of cell surface transporter exploitation in drug development and the relationship with improved therapeutic index.

Adaptive immunity, chronic inflammation and the clock

The adaptive arm of the immune system facilitates recognition of specific foreign pathogens and, via the action of T and B lymphocytes, induces a fine-tuned response to target the pathogen and develop immunological memory. The functionality of the adaptive immune system exhibits daily 24-h variation both in homeostatic processes (such as lymphocyte trafficking and development of T lymphocyte subsets) and in responses to challenge. Here, we discuss how the circadian clock exerts influence over the function of the adaptive immune system, considering the roles of cell intrinsic clockwork machinery and cell extrinsic rhythmic signals. Inappropriate or misguided actions of the adaptive immune system can lead to development of autoimmune diseases such as rheumatoid arthritis, ulcerative colitis and multiple sclerosis. Growing evidence indicates that disturbance of the circadian clock has negative impact on development and progression of these chronic inflammatory diseases and we examine current understanding of clock-immune interactions in the setting of these inflammatory conditions. A greater appreciation of circadian control of adaptive immunity will facilitate further understanding of mechanisms driving daily variation in disease states and drive improvements in the diagnosis and treatment of chronic inflammatory diseases.

Adrenocortical dysfunction in rheumatoid arthritis: Α narrative review and future directions

BACKGROUND

Iatrogenic adrenal insufficiency (AI) secondary to long-term treatment with exogenous glucocorticoids (GC) is common in patients with systematic rheumatic diseases, including rheumatoid arthritis (RA). Moreover, a proportion of these patients is always in need of even small doses of glucocorticoids to maintain clinical remission, despite concomitant treatment with conventional and biologic disease-modifying drugs.

METHODS

We conducted a literature review up to December 2020 on (a) the incidence of AI in both long-term GC-treated and GC-treatment naïve RA patients; (b) the potential effects of increased levels of circulating proinflammatory cytokines, as well as of chronic stress, in adrenocortical function in RA; (c) the circadian cortisol rhythm in RA; and (d) established and evolving methods of assessment of adrenocortical function.

RESULTS

Up to 48% of RA patients develop glucocorticoid-induced AI; however, predictors are not established, while adrenocortical dysfunction may also occur in GC-treatment naïve RA patients. Experimental and clinical data have suggested that inadequate production of endogenous cortisol relative to enhanced clinical needs associated with the systemic inflammatory response, coined as the 'disproportion principle', may operate in RA. Although the underlying mechanisms are unknown, both proinflammatory cytokines and chronic stress may contribute the most in the adrenals hyporesponsiveness and the target tissue glucocorticoid resistance that have been described, but not systematically studied. A precise longitudinal assessment of endogenous cortisol production may be needed for optimal RA management.

CONCLUSION

Apart from iatrogenic AI, an intrinsically compromised adrenal reserve in RA may have a pathogenetic role and interfere with effective management, thus deserving further research.

Catching the circadian rhythm of intervertebral disc and association with clinical outcomes by twice-a-day magnetic resonance imaging

OBJECTIVES

We conducted a prospective magnetic resonance imaging(MRI) surveillance program of the whole spine twice a day to aim at investigating the diurnal prevalence of MRI parameters of intervertebral discs and their associations with relevant symptoms.

METHODS

Sixty-four young volunteers underwent MRI of the whole spine twice on the same day (in the morning and evening). Sagittal T2-weighted MRIs of the whole spine were compared and analyzed. Two independent observers assessed the images for the disc height, anterior-posterior distance, and T2 values. Subject demographics and clinical findings were assessed by standardized questionnaires.

RESULTS

There was a statistically significant diurnal disc height change in all the disc level groups. Except four lumbar levels, there was no statistically significant diurnal disc AP distance change seen in other levels. There were statistically significant diurnal T2 value changes in all intervertebral discs except T3/4 levels. The multivariate linear regression analysis showed a positive linear trend association between BMI and the diurnal variations of T1/2 T2 value, T12/L1, L1/2, L2/3, L3/4,L4/5 and L5/S1 disc heights (p < 0.05) . Smoking and passive smoking affected cervical levels of T2 value changes. Interestingly, a reverse trend was observed in all disc changes in the case of more than ten years shift work history.

CONCLUSION

Smoking and passive smoking are associated with cervical disc T2 value diurnal changes and BMI is associated with lumbar disc height changes. Long time disruption of circadian clock may cause reverse changes of discs, however not in short or medium-time shift workers.

Operating room nurses' experiences of limited access to daylight in the workplace - a qualitative interview study

Background

The operating room nurse is, among other things, responsible for patient safety and maintaining an aseptic environment. For hygienic reasons unnecessary traffic in the operating room should be avoided, which may mean that the operating room nurse works long shifts without relief. Operating departments are usually separated, where there might be no daylight opportunities in the operating room. The purpose of the study was to describe operating room nurses’ experiences of limited access to daylight in the workplace.

Method

Qualitative design with four semi-structured focus groups of totally 15 operating room nurses. The analysis was performed with a content analysis with an inductive approach.

Results

The study generated two main categories, difference in light and contact with the outer world. Operating room nurses felt that daylight affected them differently from the light from lamps, where daylight was considered important for experiencing well-being. Daylight could lead to a sensation of joy but also increased awareness and energy which seemed to improve the ability to perform at work. The limited access to daylight contributed to fatigue and led to an internal stress that affected the nurses even after work. Having opportunities to look out through windows under a workday was important to experience contact with the outside world and created a sense of time.

Conclusion

To look out can reduce the feeling of being trapped in the closed context that the operating department entails. It can also lead to increased well-being and comfort in the workplace. We consider that daylight is an important component in the physical work environment that needs to be taken into consideration in further research as well as in new construction of operations departments.

Chronobiology and Chronotherapy in Inflammatory Joint Diseases

Circadian rhythm perturbations can impact the evolution of different conditions, including autoimmune diseases. This narrative review summarizes the current understanding of circadian biology in inflammatory joint diseases and discusses the potential application of chronotherapy. Proinflammatory cytokines are key players in the development and progression of rheumatoid arthritis (RA), regulating cell survival/apoptosis, differentiation, and proliferation. The production and secretion of inflammatory cytokines show a dependence on the human day–night cycle, resulting in changing cytokine plasma levels over 24 h. Moreover, beyond the circadian rhythm of cytokine secretion, disturbances in timekeeping mechanisms have been proposed in RA. Taking into consideration chronotherapy concepts, modified-release (MR) prednisone tablets have been introduced to counteract the negative effects of night-time peaks of proinflammatory cytokines. Low-dose MR prednisone seems to be able to improve the course of RA, reduce morning stiffness and morning serum levels of IL-6, and induce significant clinical benefits. Additionally, methotrexate (MTX) chronotherapy has been reported to be associated with a significant improvement in RA activity score. Similar effects have been described for polymyalgia rheumatica and gout, although the available literature is still limited. Growing knowledge of chronobiology applied to inflammatory joint diseases could stimulate the development of new drug strategies to treat patients in accordance with biological rhythms and minimize side effects.

Circadian rhythms affect bone reconstruction by regulating bone energy metabolism

Metabolism is one of the most complex cellular biochemical reactions, providing energy and substances for basic activities such as cell growth and proliferation. Early studies have shown that glucose is an important nutrient in osteoblasts. In addition, amino acid metabolism and fat metabolism also play important roles in bone reconstruction. Mammalian circadian clocks regulate the circadian cycles of various physiological functions. In vertebrates, circadian rhythms are mediated by a set of central clock genes: muscle and brain ARNT like-1 (Bmal1), muscle and brain ARNT like-2 (Bmal2), circadian rhythmic motion output cycle stagnates (Clock), cryptochrome 1 (Cry1), cryptochrome2 (Cry2), period 1 (Per1), period 2 (Per2), period 3 (Per3) and neuronal PAS domain protein 2 (Npas2). Negative feedback loops, controlled at both the transcriptional and posttranslational levels, adjust these clock genes in a diurnal manner. According to the results of studies on circadian transcriptomic studies in several tissues, most rhythmic genes are expressed in a tissue-specific manner and are affected by tissue-specific circadian rhythms. The circadian rhythm regulates several activities, including energy metabolism, feeding time, sleeping, and endocrine and immune functions. It has been reported that the circadian rhythms of mammals are closely related to bone metabolism. In this review, we discuss the regulation of the circadian rhythm/circadian clock gene in osteoblasts/osteoclasts and the energy metabolism of bone, and the relationship between circadian rhythm, bone remodeling, and energy metabolism. We also discuss the therapeutic potential of regulating circadian rhythms or changing energy metabolism on bone development/bone regeneration.

Circadian Rhythms, Disease and Chronotherapy

Circadian clocks are biological timing mechanisms that generate 24-h rhythms of physiology and behavior, exemplified by cycles of sleep/wake, hormone release, and metabolism. The adaptive value of clocks is evident when internal body clocks and daily environmental cycles are mismatched, such as in the case of shift work and jet lag or even mistimed eating, all of which are associated with physiological disruption and disease. Studies with animal and human models have also unraveled an important role of functional circadian clocks in modulating cellular and organismal responses to physiological cues (ex., food intake, exercise), pathological insults (e.g. virus and parasite infections), and medical interventions (e.g. medication). With growing knowledge of the molecular and cellular mechanisms underlying circadian physiology and pathophysiology, it is becoming possible to target circadian rhythms for disease prevention and treatment. In this review, we discuss recent advances in circadian research and the potential for therapeutic applications that take patient circadian rhythms into account in treating disease.

Engineered glove to evaluate hand disability in rheumatoid arthritis: A pilot-study

OBJECTIVE

The Hand Test System (HTS) is an engineered-sensorized glove that has been originally developed in the neuroscientific field for the evaluation of hand fingers' speed movement. This pilot-study aimed to evaluate the reproducibility of HTS analysis in rheumatoid arthritis (RA), correlating glove-derived parameters with clinical disease activity indexes, self-reported disability-related questionnaires and hand strength.

METHODS

Fifty-five RA patients and fifty age and sex matched healthy controls (HCs) performed HTS analysis. The glove recognized the touch speed between the finger tips during standard sequences of movements, providing three quantitative parameters: touch duration (TD), inter-tapping interval (ITI) and movement rate (MR). These variables were correlated with Health Assessment Questionnaire (HAQ), Health Assessment Questionnaire-Disease Index (HAQ-DI), Hand Disability Index (HDI), Hand Grip Strength (HGS), DAS28-CRP, CDAI and SDAI.

RESULTS

Intraclass correlation coefficient was 0.93 (CI: 0.92, 0.95). RA patients showed significantly slower TD, ITI and MR than HCs, for all classes of disease activity (P<0.001). All HTS parameters correlated significantly with HAQ, HAQ-DI, HDI, HGS, DAS28-CRP, SDAI, CDAI (between P<0.05 and P<0.001). Of note, also RA patients in clinical remission showed a significantly higher TD compared with HCs (P<0.001).

CONCLUSION

HTS seems a new safe and fast tool to evaluate rheumatoid hand's functionality, measuring the speed of finger movements. Furthermore, the HTS parameters significantly correlate with quality of life, disease activity, hand strength and perceived hand disability, evaluating also potential hand motor impairment in RA clinical remission.

Influence of Seasonal Vitamin D Changes on Clinical Manifestations of Rheumatoid Arthritis and Systemic Sclerosis

Vitamin D [1,25(OH)2D-calcitriol] is basically a steroid hormone with pleiotropic biologic effects, and its impact on the regulation of immune system may influence several clinical conditions. Calcidiol (25OHD), as precursor of calcitriol, derives, for the most part (80%), from cutaneous cholesterol (7-dehydrocholesterol) under the action of UV-B (sunlight). Consequently, serum concentrations fluctuate during the year following the circannual rhythm of sun exposition. We will update about the available evidence regarding the complex influence of seasonal vitamin D changes on two different chronic connective tissue diseases, namely rheumatoid arthritis (RA) and systemic sclerosis (SSc). Notably, RA is an emblematic model of autoimmune disease with prevalent joint inflammatory features, while SSc is mainly an autoimmune progressive pro-fibrotic disease. However, in both conditions, low serum concentrations of 25OHD are involved in the pathogenesis of the diseases, and emerging data report their impact on clinical manifestations.

Change in light-dark cycle affects experimental autoimmune encephalomyelitis

The prevalence of multiple sclerosis is associated with geographic latitude. Low sun exposure or reduced daylight hours are considered possible causes. We examined whether a change in the number of daylight hours affects the course of experimental autoimmune encephalomyelitis (EAE) disease. Housing mice in a 24-h dark or light cycle upregulated internal corticosterone secretion and ameliorated the EAE disease course relative to that in mice housed in a conventional 12/12-h cycle environment. After EAE induction, the rhythmic pattern of corticosterone secretion was disrupted. Upregulation of internal steroid secretion might act as an immunosuppressive and ameliorate EAE.

Circadian Variation in Efficacy of Medications

Although much has been learned about circadian clocks and rhythms over the past few decades, translation of this foundational science underlying the temporal regulation of physiology and behavior to clinical applications has been slow. Indeed, acceptance of the modern study of circadian rhythms has been blunted because the phenomenology of cyclic changes had to counteract the 20th century dogma of homeostasis in the biological sciences and medicine. We are providing this review of clinical data to highlight the emerging awareness of circadian variation in efficacy of medications for physicians, clinicians, and pharmacists. We are suggesting that gold-standard double-blind clinical studies should be conducted to determine the best time of day for optimal effectiveness of medications; also, we suggest that time of day should be tracked and reported as an important biological variable in ongoing clinical studies hereafter. Furthermore, we emphasize that time of day is, and should be considered, a key biological variable in research design similar to sex. In common with biomedical research data that have been historically strongly skewed toward the male sex, most pharmaceutical data have been skewed toward morning dosing without strong evidence that this is the optimal time of efficacy.

A matter of time: Circadian clocks in osteoarthritis and the potential of chronotherapy

Osteoarthritis (OA) is a common and debilitating joint disease which develops and progresses with age. Despite extensive research into the disease, potent disease-modifying drugs remain elusive. Changes to the character and function of chondrocytes of the articular cartilage underly the pathogenesis of OA. A recently emerging facet of chondrocyte biology that has been implicated in OA pathogenesis is the role of circadian rhythms, and the cellular clock which governs rhythmic gene transcription. Here, we review the role of the chondrocyte's cellular clock in governing normal homeostasis, and explore the wide range of consequences that contribute to OA development when the clock is dysregulated by aging and other factors. Finally, we explore how harnessing this understanding of clock mechanics in aging and OA can be translated into novel treatment strategies, or 'chronotherapies', for patients.

Epigenetics, pregnancy and autoimmune rheumatic diseases

Autoimmune rheumatic diseases (ARDs) are chronic conditions with a striking female predominance, frequently affecting women of childbearing age. Sex hormones and gender dimorphism of immune response are major determinants in the multifactorial pathogenesis of ARDs, with significant implications throughout reproductive life. Particularly, pregnancy represents a challenging condition in the context of autoimmunity, baring profound hormonal and immunologic changes, which are responsible for the bi-directional interaction between ARDs outcome and pregnancy course. In the latest years epigenetics has proven to be an important player in ARDs pathogenesis, finely modulating major immune functions and variably tuning the significant gender effects in autoimmunity. Additionally, epigenetics is a recognised influencer of the physiological dynamic modifications occurring during pregnancy. Still, there is currently little evidence on the pregnancy-related epigenetic modulation of immune response in ARDs patients. This review aims to overview the current knowledge of the role of epigenetics in the context of autoimmunity, as well as during physiologic and pathologic pregnancy, discussing under-regarded aspects in the interplay between ARDs and pregnancy pathology. The outline of a new ongoing European project will be presented.

Effect of an 8-Week Yoga-Based Lifestyle Intervention on Psycho-Neuro-Immune Axis, Disease Activity, and Perceived Quality of Life in Rheumatoid Arthritis Patients: A Randomized Controlled Trial

Various external stressors and environmental challenges lead to the provocation of the immune system in autoimmune diseases like Rheumatoid arthritis (RA). The inappropriate immune response further triggers the cascade of inflammatory changes resulting in precipitation of symptoms and hampers quality of life (QOL). The underlying psycho-somatic component of the disease requires a holistic approach to its treatment dimension rather than the use of pharmacotherapy. The applicability of mind-body interventions has become essential in today’s fast-paced life. Yoga, a mind-body technique, alters the mind’s capacity to facilitate systemic functioning at multiple organ system levels. Hence, we conducted this study to evaluate the impact of 8 weeks of a yoga-based lifestyle intervention (YBLI) on psycho-neuro-immune markers, gene expression patterns, and QOL in RA patients on routine medical therapy. A total of 66 patients were randomized into two groups: yoga group or non-yoga group and were assessed for a panel of inflammatory cytokines (IL-6, IL-17A, TNF-α, and TGF-β), mind-body communicative markers (BDNF, DHEAS, β-endorphin, and sirtuin) and transcript levels of various genes (IL-6, TNF-α, NFKB1, TGF-β, and CTLA4). We assessed disease activity and QOL using the DAS28-ESR and WHOQOL-BREF questionnaire, respectively. Yoga group observed significant improvements in the levels of markers, which influenced the psycho-neuro-immune axis (p < 0.001) with an estimated effect size from small to medium range. In the yoga group, there was a significant reduction in DAS28-ESR (p < 0.001) and improvement seen in the physical health, psychological, social relationships domains (p < 0.001) of QOL, except environmental (p > 0.05). The yoga group showed downregulation of IL-6, TNF-α, and CTLA4 and upregulation of TGF-β. These results suggest that a decrease in disease activity after yoga practice is associated with a significant reduction in inflammatory cytokines, the elevation of mind-body communicative markers, and normalization of various transcript levels, which improved QOL. Thus the adoption of YBLI improves clinical outcome in RA, and decreases systemic inflammation by its beneficial effects on psycho-neuro-immune axis and normalization of dysregulated transcripts. Thus YBLI may be used for RA patients as an adjunctive therapy.

Understanding the Role of Interleukin-6 (IL-6) in the Joint and Beyond: A Comprehensive Review of IL-6 Inhibition for the Management of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, debilitating autoimmune disorder involving inflammation and progressive destruction of the joints, affecting up to 1% of the population. The majority of patients with RA have one or more comorbid conditions, the most common being cardiovascular disease, osteoporosis, and depression, the presence of which are associated with poorer clinical outcomes and lower health-related quality of life. RA pathogenesis is driven by a complex network of proinflammatory cells and cytokines, and of these, interleukin-6 (IL-6) plays a key role in the chronic inflammation associated with RA. Through cell signaling that can be initiated by both membrane-bound and soluble forms of its receptor, IL-6 acts both locally to promote joint inflammation and destruction, and in the circulation to mediate extra-articular manifestations of RA, including pain, fatigue, morning stiffness, anemia, and weight loss. This narrative review describes the role of IL-6 in the pathogenesis of RA, its comorbidities, and extra-articular systemic manifestations, and examines the effects of the IL-6 receptor inhibitors sarilumab and tocilizumab on clinical endpoints of RA, patient-reported outcomes, and common comorbidities and extra-articular manifestations.

Innate Rhythms: Clocks at the Center of Monocyte and Macrophage Function

The circadian cycle allows organisms to track external time of day and predict/respond to changes in the external environment. In higher order organisms, circadian rhythmicity is a central feature of innate and adaptive immunity. We focus on the role of the molecular clock and circadian rhythmicity specifically in monocytes and macrophages of the innate immune system. These cells display rhythmicity in their internal functions, such as metabolism and inflammatory mediator production as well as their external functions in pathogen sensing, phagocytosis, and migration. These inflammatory mediators are of clinical interest as many are therapeutic targets in inflammatory disease such as cardiovascular disease, diabetes, and rheumatoid arthritis. Moreover, circadian rhythm disruption is closely linked with increased prevalence of these conditions. Therefore, understanding the mechanisms by which circadian disruption affects monocyte/macrophage function will provide insights into novel therapeutic opportunities for these chronic inflammatory diseases.

Chronotherapy targeting cytokine secretion attenuates collagen-induced arthritis in mice

OBJECTIVE

Diurnal variation of symptoms are observed in rheumatoid arthritis, especially in productions of cytokines that show peak concentrations during mid night. In contrast, cytokines of collagen-induced arthritis (CIA) mice increase in daytimes under Mid-light condition. By using chronotherapy, differences in drug efficacies according to administration time of Baricitinib, a wide ranged cytokine blocker, were examined in CIA mice.

METHODS

CIA mice were administered a dose of 3 mg/kg of Baricitinib once a day at zeitgeber time (ZT) 0 or ZT12 for 21 days. Arthritis scores, histopathology and factors related to joint destruction in sera were examined. Phosphorylation of STAT3 in liver, expressions of cytokines in spleen, and Interleukin (IL)-6 and tumor necrosis factor (TNF)-α in sera were measured.

RESULTS

In CIA mice, diurnal variations were observed both in expressions of cytokines and phosphorylation of STAT3. Arthritis scores of ZT0/12 group decreased from day3 as compared to untreated mice, and those of ZT0 group significantly decreased as compared to ZT12 group from day12. Pathological findings, immunohistochemistry of cytokines and Receptor activator of nuclear factor kappa-Β ligand (RANKL)/osteoprotegerin ratio in sera well reflected results of arthritis scores. Diurnal variation of STAT3 phosphorylation was suppressed in ZT0 group. At ZT2, expressions of IL-6/Interferon-γ/TNF/granulocyte-macrophage colony-stimulating factor in ZT0 group were significantly decreased as compared to untreated mice, though not in ZT12 group. In ZT0 group, IL-6 and TNF-α in sera were decreased for longer time than that in ZT12 group.

CONCLUSION

Chronotherapy using Baricitinib targeting cytokine secretions is effective in CIA mice. Clinical applications of chronotherapy can be expected to enhance the drug efficacy.

Moxibustion for rheumatoid arthritis: Protocol for a systematic review

BACKGROUND

Rheumatoid Arthritis (RA) is a serious chronic disease which will result in serious syndrome such as joints stiffness, disability, and death. The major medications treating RA usually make sense and side effects, while moxibustion is known as a safe and effective treatment for RA. This review aims to systematically evaluate the effect and safety of moxibustion for treating RA.

METHODS

The following databases will be searched from their inception to March 2019: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Wan-Fang Databases, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), Citation Information by National Institute of Informatics, Chinese Scientific Journal Database (VIP Database). Two reviewers will search these databases, select data and measure the quality of studies independently. The methodological quality will be assessed by the Cochrane risk of bias tool. Data will be synthesized by either the fixed-effects or random-effects model according to a heterogeneity test. The primary outcome is symptom evaluation including morning stiffness, pain and joint swelling. The number of joints affected by RA, adverse effects, quality of life, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and Rheumatoid factor (RF) will be evaluated as secondary outcomes. Risk ratio for dichotomous data and mean differences with a 95% confidence interval for continuous data will be adopted to express the effect and safety of acupuncture for RA.

RESULTS

This study will provide a high-quality synthesis of current evidence of moxibustion for asthma from several aspects including morning stiffness, pain and joint swelling. The number of joints affected by RA, adverse effects, quality of life, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and Rheumatoid factor (RF).

CONCLUSION

The conclusion of our study will provide updated evidence to judge whether moxibustion is an effective and safe intervention for patients with RA.

ETHICS AND DISSEMINATION

As individuals will not be involved, the ethical approval will not be required. This review will be published in a peer-reviewed journal or at a relevant conference.

PROSPERO REGISTRATION NUMBER

CRD42019126685.

The Impact of Intermittent Fasting (Ramadan Fasting) on Psoriatic Arthritis Disease Activity, Enthesitis, and Dactylitis: A Multicentre Study

Intermittent circadian fasting, namely Ramadan, is a common worldwide practice. Such fasting has a positive impact on psoriasis, but no data exist on its role in psoriatic arthritis (PsA)—a disease that is clearly linked to body mass index. We enrolled 37 patients (23 females and 14 males) with a mean age 43.32 ± 7.81 and they fasted for 17 h for one month in 2016. The baseline PsA characteristics were collected and 12 (32.4%) patients had peripheral arthritis, 13 (35.1%) had axial involvement, 24 (64.9%) had enthesitis, and 13 (35.1%) had dactylitis. Three patients (8.1%) were treated with methotrexate, 28 (75.7%) with TNF-α blockers, and 6 (16.2%) with IL-17 blockers. After a month of intermittent fasting, C-reactive protein (CRP) levels decreased from 14.08 ± 4.65 to 12.16 ± 4.46 (p < 0.0001), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) decreased from 2.83 ± 1.03 to 2.08 ± 0.67 (p = 0.0078), Psoriasis Area Severity Index (PASI) decreased from 7.46 ± 2.43 to 5.86 ± 2.37 (p < 0.0001), and Disease Activity index for PSoriatic Arthritis (DAPSA) decreased from 28.11 ± 4.51 to 25.76 ± 4.48 (p < 0.0001). Similarly, enthesitis improved after fasting, with Leeds Enthesitis Index (LEI) decreasing from 2.25 ± 1.11 to 1.71 ± 0.86 (p < 0.0001) and dactylitis severity score (DSS) decreasing from 9.92 ± 2.93 to 8.54 ± 2.79 (p = 0.0001). Fasting was found to be a predictor of a decrease in PsA disease activity scores (DAPSA, BASDAI, LEI, DSS) even after adjustment for weight loss. IL-17 therapy was found to be an independent predictor of decreases in LEI after fasting. These preliminary data may support the use of chronomedicine in the context of rheumatic diseases, namely PsA. Further studies are needed to support our findings.