Circadian rhythms in RA

Differences in referral path, clinical and radiographic outcomes between seronegative and seropositive rheumatoid arthritis Mexican Mestizo patients: A cohort study

BACKGROUND

The study compared the referral path, the first two-year clinical outcomes, and the first five-year radiographic outcomes between seronegative patients (SNPs) from a recent-onset rheumatoid arthritis dynamic cohort initiated in 2004 and seropositive patients (SPPs). Predictors of incidental erosive disease were investigated.

PATIENTS AND METHODS

Up to March 2023, one independent observer reviewed the charts from 188 patients with at least two years of clinical assessments and up to five years of annual radiographic assessments. SNPs were defined when baseline RF and ACPA serum titers were within local normal ranges. The erosive disease was defined on hand and/or foot radiographs when at least one unequivocal cortical bone defect was detected. The incidental erosive disease was defined in baseline erosive disease-free patients who developed erosions at follow-ups. Multivariate Cox regression analyses identified hazard ratios (95% confidence interval) for factors to predict incidental erosive disease.

RESULTS

There were 17 (9%) SNPs, and they had a shorter time from symptoms onset to first physician evaluation, visited a lower number of physicians, and received less intensive treatment at referral and during the first years of follow-up than SPPs. Also, they had fewer 0-66 swollen joints and were less frequently persistent on therapy. The erosive disease was detected only in SPPs, and its frequency increased from 10.1% at baseline to 36.1% at the five-year radiographic assessment. There were 53 (31.4%) patients with incidental erosive disease, and differences between SPPs and SNPs were statistically significant at the feet location. Incidental erosive disease was predicted by baseline ACPA, ESR, substantial morning stiffness, and cumulative CRP.

CONCLUSIONS

SNPs showed mild differences in their referral path and clinical outcomes compared to SPPs. However, erosive disease was detected only in SPPs and was predicted by baseline and cumulative clinical and serologic variables.

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.

Stress hormone signaling inhibits Th1 polarization in a CD4 T-cell-intrinsic manner via mTORC1 and the circadian gene PER1

Stress hormones are believed to skew the CD4 T‐cell differentiation towards a Th2 response via a T‐cell‐extrinsic mechanism. Using isolated primary human naïve and memory CD4 T cells, here we show that both adrenergic‐ and glucocorticoid‐mediated stress signalling pathways play a CD4 naïve T‐cell‐intrinsic role in regulating the Th1/Th2 differentiation balance. Both stress hormones reduced the Th1 programme and cytokine production by inhibiting mTORC1 signalling via two parallel mechanisms. Stress hormone signalling inhibited mTORC1 in naïve CD4 T cells (1) by affecting the PI3K/AKT pathway and (2) by regulating the expression of the circadian rhythm gene, period circadian regulator 1 (PER1). Both stress hormones induced the expression of PER1, which inhibited mTORC1 signalling, thus reducing Th1 differentiation. This previously unrecognized cell‐autonomous mechanism connects stress hormone signalling with CD4 T‐cell differentiation via mTORC1 and a specific circadian clock gene, namely PER1.

Quantification of morning stiffness to assess disease activity and treatment effects in rheumatoid arthritis

OBJECTIVES

The clinical parameter of morning stiffness is widely used to assess the status of RA, but its accurate quantitative assessment in a clinical setting has not yet been successful. This lack of individual quantification limits both personalized medication and efficacy evaluation in the treatment of RA.

METHODS

We developed a novel technology to assess passive resistance of the MCP III joint (stiffness) and its passive range of motion (PRoM). Within this pilot study, 19 female postmenopausal RA patients and 9 healthy controls were examined in the evening as well as the morning of the following day. To verify the specificity of the biomechanical quantification, 11 patients with RA were assessed both prior to and ∼3 h after glucocorticoid therapy.

RESULTS

While the healthy controls showed only minor changes between afternoon and morning, in RA patients the mean PRoM decreased significantly by 18% (s.d. 22) and stiffness increased significantly by 20% (s.d. 18) in the morning compared with the previous afternoon. We found a significant positive correlation between RA activity and biomechanical measures. Glucocorticoids significantly increased the mean PRoM by 16% (s.d. 11) and reduced the mean stiffness by 23% (s.d. 22).

CONCLUSION

This technology allowed mechanical stiffness to be quantified in MCP joints and demonstrated high sensitivity with respect to disease status as well as medication effect in RA patients. Such non-invasive, low-risk and rapid assessment of biomechanical joint stiffness opens a novel avenue for judging therapy efficacy in patients with RA and potentially also in other non-RA inflammatory joint diseases.

Association of Meal and Snack Patterns With Mortality of All-Cause, Cardiovascular Disease, and Cancer: The US National Health and Nutrition Examination Survey, 2003 to 2014

Background

Although accumulating evidence has demonstrated that consumption time of energy and macronutrients plays an important role in maintaining health, the association between consumption time of different foods and cardiovascular disease, cancer, and all‐cause mortalities is still largely unknown.

Methods and Results

A noninstitutionalized household population of the US 21 503 participants from National Health and Nutrition Examination Survey was included. Meal patterns and snack patterns throughout a whole day were measured using 24‐hour dietary recall. Principal component analysis was performed to establish dietary patterns. Cox proportional hazards models were used to evaluate the association between dietary patterns across meals and cardiovascular disease (CVD), cancer, and all‐cause mortalities. During the 149 875 person‐years of follow‐up, 2192 deaths including 676 deaths because of CVD and 476 because of cancer were documented. After adjusting for potential confounders, participants consuming fruit‐lunch had lower mortality risks of all‐cause (hazard ratio [HR], 0.82; 95% CI, 0.72–0.92) and CVD (HR, 0.66; 95% CI, 0.49–0.87); whereas participants who consumed Western‐lunch were more likely to die because of CVD (HR, 1.44; 95% CI, 1.10–1.89). Participants who consumed vegetable‐dinner had lower mortality risks of all‐cause, CVD, and cancer (HR_all‐cause, 0.69; 95% CI, 0.60–0.78; HR_CVD, 0.77; 95% CI, 0.61–0.95; HR_cancer, 0.63; 95% CI, 0.48–0.83). For the snack patterns, participants who consumed fruit‐snack after breakfast had lower mortality risks of all‐cause and cancer (HR_all‐cause, 0.78; 95% CI, 0.66–0.93; HR_cancer, 0.55; 95% CI, 0.39–0.78), and participants who consumed dairy‐snack after dinner had lower risks of all‐cause and CVD mortalities (HR_all‐cause, 0.82; 95% CI, 0.72–0.94; HR_CVD, 0.67; 95% CI, 0.52–0.87). Participants who consumed a starchy‐snack after main meals had greater mortality risks of all‐cause (HR_{after‐breakfast}, 1.50; 95% CI, 1.24–1.82; HR_{after‐lunch}, 1.52; 95% CI, 1.27–1.81; HR_{after‐dinner}, 1.50; 95% CI, 1.25–1.80) and CVD (HR_{after‐breakfast}, 1.55; 95% CI, 1.08–2.24; HR_{after‐lunch}, 1.44; 95% CI, 1.03–2.02; HR_{after‐dinner}, 1.57; 95% CI, 1.10–2.23).

Conclusions

Fruit‐snack after breakfast, fruit‐lunch, vegetable‐dinner, and dairy‐snack after dinner was associated with lower mortality risks of CVD, cancer, and all‐cause; whereas Western‐lunch and starchy‐snack after main meals had greater CVD and all‐cause mortalities.

Time-of-day effects on the postural control and symptoms in women with rheumatoid arthritis

The present study was designed to assess time-of-day effects on postural balance and symptoms of rheumatoid arthritis (RA) patients. A total of 15 American College of Rheumatology functional class I and II RA patients and 15 healthy controls aged between 45 and 55 (mean age: 50 ± 3) years of age voluntarily participated. We conducted a case-control, repeated-measures in design study. Postural balance, axillary temperature, pain intensity, fatigue, and sleepiness were measured during five test sessions at 06:00, 10:00, 14:00, 18:00, and 22:00 h. Participants were randomized to the order of test sessions, and each session was separated by >36 hours to minimize/eliminate learning effects. Center of pressure area (CoP_area) (p < .001), pain (p < .01), and sleepiness (p < .05) values were significantly higher at 06:00 and 22:00 h compared to 10:00, 14:00, and 18:00 h in the RA group. Fatigue significantly increased (p < .05) at 22:00 h in comparison to 10:00, 14:00, and 18:00 h in the RA group. Axillary temperature was significantly (p < .001) lower at 06:00 and at 22:00 h compared to 10:00, 14:00, and 18:00 h in the RA group. In the control group, there were no significant time-of-day difference in fatigue, but axillary temperature was significantly lower (p < .01) at 06:00 h compared to 10:00 h, 14:00, 18:00, and 22:00 h, sleepiness values were significantly higher (p < .05) at 06:00 and 22:00 h compared to 10:00, 14:00, and 18:00 h, and revealed CoP_area values were significantly (p < .05) higher at 06:00 h compared to 14:00 h. Finally, in the RA group, significant correlations were found between values of CoP_area and pain (r = 0.47; p < .001), sleepiness (r = 0.39; p < .01), fatigue (r = -0.46; p < .001), and also axillary temperature (r = -0.35; p < .001). Multiple linear regression analysis further indicated that in the RA group, time-of-day variation in postural balance was predicted collectively by that in pain and fatigue (30.7%) (R2 = 0.307; F = 11.53; p < .001). Our results first suggest that time-of-day significantly affects postural balance, axillary temperature, pain intensity, fatigue, and sleepiness in RA patients and second that the temporal variation observed in pain, fatigue, and somnolence are concomitant with that observed in postural balance.Abbreviations: RA: Rheumatoid arthritis; H&O questionnaire: Horne and Ostberg questionnaire; PSQI: Pittsburgh sleep quality index; HAQ: Health assessment questionnaire; SF-36: the short form-36; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; CoP: The Center of foot Pressure; CoP_area: The Center of foot Pressure area; VAS: The Visual Analogue Scale; KSS: Karolinska Sleepiness Scale.

Neuroimmune Interactions and Rhythmic Regulation of Innate Lymphoid Cells

The Earth’s rotation around its axis, is one of the parameters that never changed since life emerged. Therefore, most of the organisms from the cyanobacteria to humans have conserved natural oscillations to regulate their physiology. These daily oscillations define the circadian rhythms that set the biological clock for almost all physiological processes of an organism. They allow the organisms to anticipate and respond behaviorally and physiologically to changes imposed by the day/night cycle. As other physiological systems, the immune system is also regulated by circadian rhythms and while diurnal variation in host immune responses to lethal infection have been observed for many decades, the underlying mechanisms that affect immune function and health have only just started to emerge. These oscillations are generated by the central clock in our brain, but neuroendocrine signals allow the synchronization of the clocks in peripheral tissues. In this review, we discuss how the neuroimmune interactions create a rhythmic activity of the innate lymphoid cells. We highlight how the disruption of these rhythmic regulations of immune cells can disturb homeostasis and lead to the development of chronic inflammation in murine models.

Tissue physiology revolving around the clock: circadian rhythms as exemplified by the intervertebral disc

Circadian clocks in the brain and peripheral tissues temporally coordinate local physiology to align with the 24 hours rhythmic environment through light/darkness, rest/activity and feeding/fasting cycles. Circadian disruptions (during ageing, shift work and jet-lag) have been proposed as a risk factor for degeneration and disease of tissues, including the musculoskeletal system. The intervertebral disc (IVD) in the spine separates the bony vertebrae and permits movement of the spinal column. IVD degeneration is highly prevalent among the ageing population and is a leading cause of lower back pain. The IVD is known to experience diurnal changes in loading patterns driven by the circadian rhythm in rest/activity cycles. In recent years, emerging evidence indicates the existence of molecular circadian clocks within the IVD, disruption to which accelerates tissue ageing and predispose animals to IVD degeneration. The cell-intrinsic circadian clocks in the IVD control key aspects of physiology and pathophysiology by rhythmically regulating the expression of ~3.5% of the IVD transcriptome, allowing cells to cope with the drastic biomechanical and chemical changes that occur throughout the day. Indeed, epidemiological studies on long-term shift workers have shown an increased incidence of lower back pain. In this review, we summarise recent findings of circadian rhythms in health and disease, with the IVD as an exemplar tissue system. We focus on rhythmic IVD functions and discuss implications of utilising biological timing mechanisms to improve tissue health and mitigate degeneration. These findings may have broader implications in chronic rheumatic conditions, given the recent findings of musculoskeletal circadian clocks.

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.

Rheumatoid Arthritis: The Impact of Mental Health on Disease: A Narrative Review

Over 60% of rheumatoid arthritis (RA) patients achieve a good response after 12 months of treatment when following the European league against rheumatism (EULAR) guidelines for treatment. However, almost half of patients still suffer from moderate to severe disease activity despite this. In addition, mental health problems may remain despite reduced measures of inflammation systemically and within joints. Depression is two times more common in RA patients than in the general population, and intriguingly a bi-directional relationship with RA has been shown in cross-sectional studies. Chronic inflammation impairs the physiological responses to stress including effective coping behaviours, resulting in depression, which leads to a worse long-term outcome in RA. In RA patients, the pain score is not always solely related to inflammatory arthritis and immunological disease activity by Bąk et al. (Patient Prefer Adherence 13:223-231, [1]). Non-inflammatory pain secondary to anxiety, depression, sleep disturbance and the psychosocial situation needs to be considered whilst fibromyalgia, mechanical pain and neuropathic pain can also contribute to overall pain scores by Chancay et al. (Women's Midlife Health 5:3, [2]). Hence, the UK National Institute for Health and Care Excellence (NICE) guideline for the management of RA included psychological interventions for fatigue, low mood and social well-being (NICE NG100, 2018) [3], and the NICE clinical guidelines (CG91) [4] suggest managing mental health and depression in chronic medical conditions to improve treatment outcomes. This is a narrative review of the impact of mental health on RA disease activity in terms of patient-reported outcomes (PROs).

Time is on the Immune System's Side, Yes it is

From bacteria to mammals, nearly all organisms have adapted their physiology and behavior to a daily rhythm. These circadian (daily) rhythms influence virtually all aspects of physiological architecture (i.e., from gene expression to organismal behavior). Therefore, it is not surprising that several features of the immune response are regulated in a time-of-day dependent manner. The field of chrono-immunology has expanded tremendously over the past decade. In this abridged review, we present studies from the past five years that have revealed new parameters of the immune system that demonstrate daily variations in the control of pathogens and response to microbial components. These studies analyzed how the disruption of circadian rhythms impairs immune function, how microbial components alter the circadian clock, and how immune responses demonstrate daily variations in human subjects. Further elucidating the intricate connections between the circadian clock and the immune system will hopefully provide opportunities for chrono-immunotherapy in disease treatment and prevention.

Role of methotrexate chronotherapy in collagen-induced rheumatoid arthritis in rats

Aim

To explore the circadian rhythm of serum interleukin (IL)-6 in collagen-induced arthritis (CIA) rats and compare the safety and effectiveness of methotrexate (MTX) administered traditionally and via chronotherapy.

Methods

CIA rat models were immunized with bovine type II collagen. Serum IL-6 levels in normal and CIA rats were measured at 2, 6, 10, 14, 18, or 22 h after the light was turned on (HALO). MTX was administered to 6 HALO/18 HALO experimental groups of Wistar rats once daily according to the IL-6 rhythm. The control groups (positive, negative, and normal) were given MTX or an equal volume of phosphate buffered saline (PBS) once a week simultaneously. Arthritis score, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C reactive protein (CRP) levels in the serum were measured by enzyme-linked immunosorbent assay (ELISA). Histological changes in the ankle joint were analyzed.

Results

After 6 weeks of treatment, arthritis scores in the experimental group were lower than in the control group. The expression of TNF-α, IL-6, and CRP was lower in the 18 HALO group than in the control or 6 HALO groups. Histopathology scores in the experimental groups were lower than in the control group (p < 0.05).

Conclusion

The plasma IL-6 levels in CIA rats were higher than in normal rats and showed significant circadian rhythm. Daily administration of MTX is more potent than weekly administration. The therapeutic index of rheumatoid arthritis (RA) may be improved with MTX therapy based on the IL-6 circadian rhythm.

Complement systems C4, C3 and CH50 not subject to a circadian rhythm

Background:

The circadian fluctuations in the blood levels of selected components of the complement system are ill-defined. Some authors found nadir serum levels of C4 and C3 components, together with C3a at nighttime, while others reported insomnia when pro-inflammatory components exhibited increased serum levels. In this study, we quantitatively estimate the morning and evening daytime serum levels of CH50, C4, C3, put into context with C-reactive protein (CRP), cortisol, parathyroid hormone (PTH) and 25(OH)vitamin D at 07:00 A.M. and at 07:00 P.M.

Methods:

Seven healthy adult women and 11 men who were voluntary participants agreed to a fasting venipuncture in the morning after having normally eaten through the day and in the evening. The C4 and C3 serum levels were measured on a Cobas (Roche Diagnostics, Switzerland) modular analyzer, CH50 was estimated using the COMPL300 enzyme-linked immunosorbent assay (ELISA) of Wieslab (Malmö, Sweden). CRP, 25(OH)vitamin D, PTH and cortisol concentrations were assessed with electro-chemiluminescence immunoassay (ECLIA) on the Roche Cobas 6000 platform; IgG was measured using nephelometry (Siemens, Germany).

Results:

With the exception of higher PTH levels in the evening [3.12–5.46, 95% confidence interval (CI)] compared to the morning (2.93–4.65, 95% CI), the mean and median values of C4, C3, CH50 as well as CRP, PTH and 25(OH)vitamin D fell within the established reference intervals. Cortisol levels were measured as an internal positive control for diurnal fluctuations (morning: 294–522 nmol/L, 95% CI; evening: 106–136 nmol/L, 95% CI).

Conclusions:

The concentrations of the assessed complement components C4 and C3 as well as CH50 surrogate assay did not yield significantly different values between early morning and evening. This does not exclude their participation in the circadian metabolome; this pilot study with healthy participants suggests that patients with an autoimmune disease in remission can give their blood samples independently during daytime with or without fasting.

Air Travel, Circadian Rhythms/Hormones, and Autoimmunity

Biological rhythms are fundamental for homeostasis and have recently been involved in the regulatory processes of various organs and systems. Circadian cycle proteins and hormones have a direct effect on the inflammatory response and have shown pro- or anti-inflammatory effects in animal models of autoimmune diseases. The cells of the immune system have their own circadian rhythm, and the light-dark cycle directly influences the inflammatory response. On the other hand, patients with autoimmune diseases characteristically have sleep disorders and fatigue, and in certain disease, such as rheumatoid arthritis (RA), a frank periodicity in the signs and symptoms is recognized. The joint symptoms predominate in the morning, and apparently, subjects with RA have relative adrenal insufficiency, with a cortisol peak unable to control the late night load of pro-inflammatory cytokines. Transatlantic flights represent a challenge in the adjustment of biological rhythms, since they imply sleep deprivation, time zone changes, and potential difficulties for drug administration. In patients with autoimmune diseases, the use of DMARDs and prednisone at night is probably best suited to lessen morning symptoms. It is also essential to sleep during the trip to improve adaptation to the new time zone and to avoid, as far as possible, works involving flexible or nocturnal shifts. The study of proteins and hormones related to biological rhythms will demonstrate new pathophysiological pathways of autoimmune diseases, which will emphasize the use of general measures for sleep respect and methods for drug administration at key daily times to optimize their anti-inflammatory and immune modulatory effects.

Glucocorticoid management in rheumatoid arthritis: morning or night low dose?

Morning symptoms of rheumatoid arthritis (RA) are linked to circadian increase of night inflammation, supported by inadequate cortisol secretion in active disease. Therefore, exogenous glucocorticoid administration in RA is recommended by EULAR and ACR from the beginning of the diagnosis, since may partially act like a "replacement therapy". In addition, the prevention/treatment of the night up-regulation of the immune/inflammatory reaction has been shown more effective when exogenous glucocorticoid administration is managed with a night-time-release formulation. Despite a considerably higher cost than conventional prednisone (immediate release), chronotherapy with night-time-release prednisone has been recognized a cost-effective option for RA patients not on glucocorticoids who are eligible for therapy with biologic disease-modifying antirheumatic drugs (DMARDs). Interestingly, since different cell populations involved in the inflammatory process are particularly activated during the night (i.e. monocytes, macrophages), other therapeutical approaches used in RA, such as conventional DMARDs and non-steroidal anti-inflammatory drugs (NSAIDs) should follow the same concepts of glucocorticoid chronotherapy. Therefore, bedtime methotrexate chronotherapy was found to better manage RA symptoms, and several available NSAIDs (i.e. indomethacin, aceclofenac, ketoprofen, flurbiprofen, lornoxicam) have been recently modified in their formulation, in order to obtain more focused night action.

Switching From Immediate-Release to Delayed-Release Prednisone in Moderate to Severe Rheumatoid Arthritis: A Practice-Based Clinical Study

Introduction

Rheumatoid arthritis (RA) produces debilitating morning stiffness. Exogenous glucocorticoids can help with these symptoms when timed appropriately. Bedtime dosing of delayed-release prednisone (DR-prednisone) matches the rise of inflammatory cytokines before awakening and can improve stiffness and other RA symptoms. A prospective open-label study was conducted in patients currently on stable doses of immediate-release prednisone (IR-prednisone) who were switched to DR-prednisone to analyze the incremental benefit of better timed and lower dose glucocorticoid therapy.

Methods

Twelve US sites enrolled patients with moderate-severe RA into a 12-week prospective study. Patients were switched from IR- to DR-prednisone while maintaining other existing background therapies. Change from baseline in morning stiffness severity, morning stiffness duration, swollen and tender joint counts (S-TJC), 28 joint disease activity score (DAS28), and patient/physician global assessment (PGA/PhGA), among others, were measured. Post-hoc analyses were performed on those completing 10 weeks of treatment and those with >60 min of morning stiffness at baseline.

Results

Fifty-six patients had at least one follow-up visit and were similar in demographics to previous controlled trials with DR-prednisone with regard to baseline age and DAS28-CRP but had lower morning stiffness and RA duration. DR-prednisone produced a trend toward lower morning stiffness severity and duration with a reduction in daily prednisone dose of almost 1 mg. Patients treated with DR-prednisone for ≥10 weeks demonstrated significant reductions in morning stiffness duration, SJC, TJC, DAS28-CRP, and PhGA (all p ≤ 0.04). Patients treated for ≥10 weeks with >60 min of baseline morning stiffness produced similar results in these measures as well as a 21% reduction in morning stiffness severity (p = 0.02).

Conclusion

Patients switched to DR-prednisone from IR-prednisone in this practice-based study maintained or improved their outcomes across a variety of domains, and results were comparable to previous controlled trials in which patients completed at least 10 weeks of treatment.

Funding

Horizon Pharma USA, Inc.

Trial Registration

ClinicalTrials.gov identifier, NCT02287610.

Cytokine and Growth Factor Concentrations in Canine Autologous Conditioned Serum

OBJECTIVE

To compare cytokine and growth factor concentrations in canine autologous conditioned serum (ACS) to canine plasma.

STUDY DESIGN

Experimental in vivo study.

ANIMALS

Client-owned, adult dogs (n=22).

METHODS

Blood collected from 16 medium to large breed dogs was used to produce ACS (Orthokine(®) vet irap 10 syringes) and citrated plasma (control). Canine-specific ELISA assays were run per manufacturers' instructions for interleukin (IL)-10, IL-4, tumor necrosis factor (TNF)-α, insulin-like growth factor (IGF)-1, fibroblast growth factor (FGF)-2, transforming growth factor (TGF)-β1, IL-1β, and interleukin-1 receptor antagonist (IL-1ra). Serum, in addition to plasma and ACS, was collected from an additional 6 dogs for TNF-α, IL-1β, and IL-1ra analysis (total of 22 dogs). Data were analyzed for differences in each cytokine concentration using pairwise comparisons between ACS, plasma, and serum using Wilcoxon signed-rank tests. Significance was set at P<.05.

RESULTS

There was a large variability in growth factor and cytokine concentrations in ACS and plasma for individual dogs. There were no significant differences in IL-10, TNF-α, IGF-1, FGF-2, and TGF-β1 concentrations between ACS, plasma, and serum. The IL-1β concentrations in ACS (median, range 46.3 pg/mL, 0-828.8) and IL-4 (0.0 pg/mL, 0-244.1) were significantly higher than plasma (36.6 pg/mL, 0-657.1 and 0.0 pg/mL, 0-0, respectively). The IL-1ra concentration in ACS (median, range 3,458.9 pg/mL, 1,243.1-12,089.0) was significantly higher than plasma (692.3 pg/mL, 422.5-1,475.6). The IL-1ra:IL-1β ratio in ACS was significantly higher than plasma (39.9 vs. 7.2).

CONCLUSION

IL-1ra concentrations in canine ACS were comparable to those published for people and horses and pro-inflammatory cytokines remained low in canine ACS.

Circadian variations in clinical symptoms and concentrations of inflammatory cytokines, melatonin, and cortisol in polymyalgia rheumatica before and during prednisolone treatment: a controlled, observational, clinical experimental study

BACKGROUND

In contrast to rheumatoid arthritis (RA), no systematic investigation of diurnal variation has been carried out in polymyalgia rheumatica (PMR). The aim of the study was to provide the often-requested documentation of the 24-h time course of clinical symptoms in PMR and relate them to concentrations during the day of melatonin, inflammatory cytokines, and cortisol. Furthermore, the effects of 14 days of prednisolone treatment were studied.

METHODS

Ten glucocorticoid-naive patients newly diagnosed with PMR and seven non-PMR control subjects were studied for 24 h before treatment and during the 14th day of treatment with 20 mg/day of prednisolone. Global pain and generalized muscle stiffness were monitored by using visual analogue scales, and blood was drawn repeatedly.

RESULTS

In untreated patients, pain and stiffness peaked in the early morning, showing a plateau between 04:00 and 08:00, and then declined to a nadir at 16:00 (2P < 0.05). Plasma concentrations of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, IL-1β, and IL-4 varied with time in both groups (2P < 0.05) and peaked between 04:00 and 08:00. Furthermore, except for IL-1β, concentrations of these cytokines and of IL-10 were higher throughout the 24-h observation period in patients than in control subjects (2P < 0.05). Also, melatonin and cortisol were consistently higher in patients (2P < 0.05) and varied with time (2P < 0.05), peaking around 02:00 and 08:00, respectively. In patients, prednisolone abolished symptoms, normalized C-reactive protein, and reduced melatonin, IL-6, IL-8, and TNF-α concentrations (2P < 0.05), while IL-10 increased between 10:00 and 14:00.

CONCLUSIONS

In PMR, key symptoms show diurnal variation. Furthermore, in PMR, concentrations of melatonin, several pro- and anti-inflammatory cytokines, and cortisol are increased throughout the day and show diurnal variation, as also seen in healthy subjects. The time courses and the inhibitory effects of prednisolone indicate that in PMR, as proposed for RA, melatonin stimulates cytokine production, which in turn accounts at least partly for the symptoms. Furthermore, overall, cortisol may downregulate cytokine production and symptoms. Stimulation of IL-10 secretion may participate in the anti-inflammatory effects of prednisolone. These findings support use of chronotherapy in PMR and encourage study of circadian variations in other inflammatory autoimmune diseases.

What Is the Relationship Between Morning Symptoms and Measures of Disease Activity in Patients With Rheumatoid Arthritis?

OBJECTIVE

Little is known about the relationship between morning symptoms of rheumatoid arthritis (RA) and measures of disease activity currently used to assess RA. Information available from the Circadian Administration of Prednisone in Rheumatoid Arthritis (CAPRA-2) study was used to investigate these relationships.

METHODS

CAPRA-2 included 350 patients with RA who were symptomatic despite treatment with disease-modifying antirheumatic drugs, randomized 2:1 to additional treatment with a 5-mg daily dose of delayed-release prednisone or placebo. Pearson's correlations were used to evaluate the relationships between change from baseline in symptoms (duration of morning stiffness, severity of morning stiffness, and intensity of pain on waking) and measures of disease activity (the American College of Rheumatology 20% improvement criteria [ACR20], the Disease Activity Score in 28 joints [DAS28], and the Health Assessment Questionnaire disability index). Correlations were defined as weak (<0.3), moderate (0.3-0.7), or strong (>0.7).

RESULTS

There was a strong correlation between the severity of morning stiffness and the intensity of morning pain (Pearson's correlation 0.91, P < 0.001). There was a weak correlation between the duration of morning stiffness and measures of disease activity (0.24-0.28), with moderate correlations between the severity of morning stiffness or intensity of pain on waking and DAS28 or ACR20 scores (0.44-0.48). Severity of morning stiffness showed less variability and a greater effect size than did duration of morning stiffness.

CONCLUSION

Morning symptoms and measures of disease activity show weak to moderate correlations. Severity of morning stiffness showed less variability and greater effect size than did duration of morning stiffness. These findings suggest that severity is the preferred construct to measure the impact of morning stiffness in patients with RA, information that is not fully captured in the RA core set.

Glucocorticoids and chronotherapy in rheumatoid arthritis

It is evident that the morning symptoms of rheumatoid arthritis (RA) are linked to the circadian abnormal increase in night inflammation, favoured by inadequate cortisol secretion under conditions of active disease. Therefore, exogenous glucocorticoid treatment is recommended in RA at low doses since it may partially act like a ‘replacement therapy’. The prevention/treatment of the night upregulation of the immune/inflammatory reaction (and related flare of cytokine synthesis) has been shown to be more effective when exogenous glucocorticoid administration is obtained with a night-time-release formulation. Large-scale trials documented that modified-release prednisone has greater efficacy then morning prednisone for long-term low-dose glucocorticoid treatment in patients with RA, showing at least a more significant reduction in morning joint stiffness. Interestingly, despite a considerably higher cost than conventional prednisone, chronotherapy with night-time-release prednisone was recognised as a cost-effective option for patients with RA not on glucocorticoids who are eligible for therapy with biological disease-modifying antirheumatic drugs (DMARDs). Moreover, since different cell populations involved in the inflammatory process are particularly activated during the night, other therapeutical approaches used in RA, for example, conventional DMARDs and non-steroidal anti-inflammatory drugs (NSAIDs), should follow the same concepts of glucocorticoid chronotherapy. Indeed, bedtime methotrexate chronotherapy was found to improve RA symptoms compared to the current standard dosing methods, and several available NSAIDs (ie, indomethacin, aceclofenac, ketoprofen, flurbiporfen, lornoxicam) have been very recently modified in their formulation, in order to obtain chronotherapeutical effects in RA.

Association of Nocturnal Hypertension With Disease Activity in Rheumatoid Arthritis

OBJECTIVES

Both nocturnal hypertension (HT) and systemic inflammation underlying rheumatoid arthritis (RA) have been shown to be independent predictors of cardiovascular disease (CVD), although little is known on the relationship between nocturnal blood pressure (BP) and disease activity in RA patients.

METHODS

We performed 24-hour ambulatory BP monitoring (ABPM) in 71 RA patients to examine the relationship of nocturnal fall in BP and RA disease activity based on a disease activity score of 28 joint counts with C-reactive protein (CRP, 28-joint disease activity score (DAS28)-CRP). Among them, 25 RA patients whose consent obtained were reexamined by ABPM to assess the improvement of nocturnal fall in BP after RA therapeutic intervention.

RESULTS

The mean DAS28-CRP level was 4.8±1.6 in 71 RA patients. The mean nocturnal fall in BP was 5.6±8.9%. DAS28-CRP was associated significantly and independently in a negative manner with the nocturnal fall in BP (β = -0.388, P = 0.004). In 25 RA patients, DAS28-CRP improved from 5.4±1.1 to 3.5±0.8 (P < 0.0001) and the nocturnal fall in BP increased significantly from 4.5±9.2% to 10.6±5.8% (P = 0.002) with the significant decrease of nighttime systolic BP (SBP) from 121.2±22.5mm Hg to 112.5±18.8mm Hg (P = 0.02) in spite of no change in daytime BP after 4 weeks of RA treatment.

CONCLUSIONS

The present study observed that higher RA activity was associated with lower nocturnal fall in BP, but not daytime BP, in RA patients.

A pH-triggered delayed-release chronotherapeutic drug delivery system of aceclofenac for effective management of early morning symptoms of rheumatoid arthritis

CONTEXT

Rheumatoid arthritis (RA) is differentiated as an early morning exacerbation of the core arthritis condition associated with increase in pain and stiffness in joints and necessitate for medication.

OBJECTIVE

The aim of the present work was to develop and optimise a pH-triggered delayed-release colon-specific aceclofenac microspheres and to accomplish chronotherapy of RA.

METHODS

A 3-factor, 3-level Box-Behnken design (BBD) was used to optimise selected variables. Developed formulation was evaluated for in vivo delayed response and anti-arthritis activity in rats.

RESULTS

The particle size and encapsulation efficacy of these microspheres were 117.36 ± 10.54 µm and 85.06 ± 5.85%, respectively. Optimised formulation was analysed by SEM, DSC, X-RPD and FTIR. The in vivo evaluation revealed delayed anti-inflammatory activity in carrageenan-induced rats and anti-arthritic activity in freund's adjuvant-induced arthritis rats.

CONCLUSION

The optimised aceclofenac microspheres formulation is potential for the chronotherapy of early morning symptoms of RA.

Morning stiffness response with delayed-release prednisone after ineffective course of immediate-release prednisone

Objective: To assess morning stiffness in rheumatoid arthritis (RA) patients switched from immediate-release (IR) to delayed-release (DR) prednisone.

Method: Circadian Administration of Prednisone in Rheumatoid Arthritis-1 (CAPRA-1) is a 12-week, randomized, multicentre, active-controlled study of morning stiffness that consisted of a double-blind phase and a 9-month open-label extension. Patients receiving IR prednisone with no significant improvement after the double-blind study were switched to DR prednisone. Morning stiffness duration and median absolute and relative changes in pain and global assessment were evaluated (3, 6, and 9 months).

Results: In patients switched from IR to DR prednisone (n = 110), statistically significant reductions in morning stiffness occurred over 3 months and were sustained for 9 months. Absolute reduction of morning stiffness was ~50 min with > 40% relative reduction at each visit. Interleukin (IL)-6 levels were reduced by the same amount. Statistically significant and clinically meaningful mean reductions in morning stiffness were maintained at > 67 min at each visit along with significant improvements in pain and patient global assessment. There was no evidence of tachyphylaxis seen over the 9-month study.

Conclusions: Patients receiving disease-modifying anti-rheumatic drugs (DMARDs) and IR prednisone who had not had significant reductions in morning stiffness demonstrated statistically significant and clinically meaningful improvements when switched to DR prednisone.

Circadian use of glucocorticoids in rheumatoid arthritis

A clear temporal relationship exists in rheumatoid arthritis (RA) patients between increased nocturnal levels of pro-inflammatory cytokines, such as TNF-α and interleukin (IL)-6, pro-inflammatory hormones (i.e. melatonin, prolactin) and insufficient night production of the anti-inflammatory cortisol (circadian rhythm). Under long-standing chronic stress of disease, insufficient cortisol is available to inhibit an ongoing nocturnal immune/inflammatory reaction. Clinical RA symptoms follow the same circadian rhythm with highest morning severity. Chronotherapy with nighttime glucocorticoid (GC) availability optimizes the treatment of RA patients with low-dose GCs through more efficient targeting of mediators of the immune/inflammatory reaction during the night to be available on arising. Circadian use of low-dose, long-term prednisone, by using night-release formulations (ingested at 10 to 11 p.m.) especially in early RA patients, appears characterized by a significantly superior efficacy on decreasing morning stiffness and IL-6 serum levels, compared to conventional daytime immediate-release prednisone. Shift from medium-dose, immediate-release prednisone (over 7.5-10 mg/day) to night-release formulations GC low-dose, long-term chronotherapy requires a gradual passage, since the hypothalamic-pituitary-adrenal axis of the treated RA patients, potentially altered by a negative feedback induced by the medium/high daily exogenous GC administration, needs time to re-synchronize control of endogenous GC production into a circadian and more physiological nocturnal hormone availability/optimized efficacy.

Modified-release prednisone: in patients with rheumatoid arthritis

Prednisone is a well-established treatment option in rheumatoid arthritis. Low-dose glucocorticoid therapy alleviates disease signs and symptoms, is better tolerated than high-dose therapy, and its addition to disease-modifying anti-rheumatic drugs (DMARDs) inhibits radiographic disease progression. A low-dose, modified-release (MR) formulation of prednisone, administered in the evening, was developed to counter the circadian rise in pro-inflammatory cytokine levels that contributes to disease activity. In a 12-week, randomized trial (CAPRA-2) in adult patients with rheumatoid arthritis who were receiving stable DMARD therapy, the addition of MR prednisone reduced disease signs and symptoms by ≥20 % according to the American College of Rheumatology criteria (in 48 % of patients vs. 29 % with placebo; p < 0.002 [primary endpoint]). In another 12-week trial (CAPRA-1), addition of evening MR prednisone to stable DMARD therapy reduced the mean duration of morning stiffness to a greater extent than addition of morning immediate-release (IR) prednisone (22.7 vs. 0.4 %; p = 0.045 [primary endpoint]). The improvement in morning stiffness with MR prednisone was maintained for 9-12 months during the open-label extension of CAPRA-1. These findings were supported by data from observational studies in various adult populations with rheumatoid arthritis. Treatment with evening MR prednisone for up to 12 months was generally well tolerated, with an overall similar tolerability profile compared with evening placebo or morning IR prednisone, and no new safety concerns. MR prednisone was estimated to be cost effective relative to IR prednisone in patients with rheumatoid arthritis in a UK pharmacoeconomic model.

Diurnal variation of gait in patients with rheumatoid arthritis: The DIVIGN study

BACKGROUND

Circadian variation of joint stiffness (morning stiffness) and its impact on functional ability are widely recognised in rheumatoid arthritis. Subsequent within-day variation of walking ability is important due to the increased availability of instrumented gait analysis. This study aimed to quantify diurnal variation of gait in patients with rheumatoid arthritis, and explore associations with disease characteristics.

METHODS

Thirty one inpatients with rheumatoid arthritis walked at a self-selected speed along a GAITRite instrumented walkway 5 times during a single day.

FINDINGS

Participants showed marked diurnal variation in gait, leading to a systematic variation throughout the day (F=19.56, P=<0.001). Gait velocity and stride length both increased, whereas the proportion of each gait cycle spent in stance phase or double support decreased, consistent with improving function throughout the day. Although absolute gait velocity correlated with disease characteristics, the magnitude of diurnal variation appeared to be independent of disease activity (rho=0.26, P=0.15), disease duration (rho=-0.19, P=0.324), and underlying functional ability (rho=0.09, P=0.65).

INTERPRETATION

Although morning stiffness is well recognised in rheumatoid arthritis, this is the first time that its effect on gait has been quantified. Patients with rheumatoid arthritis exhibited a systematic change in walking ability throughout the day, which was independent of disease characteristics. These findings have important implications for the interpretation of existing data and the design of future studies. Repeat measures should be conducted at the same time of day to exclude the effects of diurnal variation.

Cytokines as biomarkers in rheumatoid arthritis

RA is a complex disease that develops as a series of events often referred to as disease continuum. RA would benefit from novel biomarker development for diagnosis where new biomarkers are still needed (even if progresses have been made with the inclusion of ACPA into the ACR/EULAR 2010 diagnostic criteria) and for prognostic notably in at risk of evolution patients with autoantibody-positive arthralgia. Risk biomarkers for rapid evolution or cardiovascular complications are also highly desirable. Monitoring biomarkers would be useful in predicting relapse. Finally, predictive biomarkers for therapy outcome would allow tailoring therapy to the individual. Increasing numbers of cytokines have been involved in RA pathology. Many have the potential as biomarkers in RA especially as their clinical utility is already established in other diseases and could be easily transferable to rheumatology. We will review the current knowledge's relation to cytokine used as biomarker in RA. However, given the complexity and heterogeneous nature of RA, it is unlikely that a single cytokine may provide sufficient discrimination; therefore multiple biomarker signatures may represent more realistic approach for the future of personalised medicine in RA.

Mechanism of the 24-hour rhythm of tumor necrosis factor-alpha formed by onset of rheumatoid arthritis

OBJECTIVE

Morning stiffness and plasma cytokine levels in rheumatoid arthritis (RA) patients exhibit 24-hour variations. Tumor necrosis factor-α (TNF-α) plays a central role in RA clinical conditions, including the invasion of inflammatory cells, destruction of cartilage, systemic inflammatory response and its levels show a 24-hour rhythm after the onset of RA. In this study, we investigated what cytokines and/or transcriptional factors are involved in the formation of 24-hour variations in TNF-α levels after the onset of RA using MRL/Mpj-Tnfrsf6(lpr) (MRL/lpr) mice.

METHOD

Blood was drawn at six different times from MRL/lpr mice to measure cytokines, serum amyloid A (SAA), IgG rheumatoid factor (IgG-RF) and corticosterone levels. Cytokine and transcriptional factor levels at the different times were measured in 10- and/or 15-week-old MRL/lpr mice. The promoter activity of TNF-α by lymphotoxins (LTs) was investigated using a dual-luciferase assay.

RESULTS

SAA and TNF-α concentrations clearly exhibited 24-hour rhythms with higher levels at the light phase and lower levels at the dark phase after RA crisis. The expression of LT-α and LT-β showed significant 24-hour rhythms in 15-week-old MRL/lpr mice and the phases of LT-α and LT-β levels were antiphase compared with that of TNF-α. AP-1 binding sites were found in LT-α and LT-β promoter regions, and jun mRNA expression corresponded to LT-α and LT-β levels. TNF-α promoter activity was decreased due to the co-transfection of LT-α and LT-β.

CONCLUSION

LT-α and LT-β controls the 24-hour rhythm in TNF-α levels after the onset of RA in order to suppress TNF-α promoter activity.

Measurement of stiffness in patients with rheumatoid arthritis in low disease activity or remission: a systematic review

BACKGROUND

Recent qualitative research has shown that stiffness is an important symptom for patients to identify remission. However, it is unclear how to measure stiffness in low disease activity. This systematic review aims to summarise the existing literature on validity of patient reported outcomes to measure stiffness in RA low disease activity states, to aid the choice for a measurement instrument.

METHODS

An extensive pubmed-search was undertaken, identifying measurement instruments for patient perceived stiffness used in low disease activity. Eligible studies reported on 1) stiffness as an outcome in relation to other core set measures, 2) development of a patient reported tool to measure stiffness, or 3) comparison of two different tools to measure aspects of stiffness, all in low disease activity.

RESULTS

Of 788 titles, only two studies report on validity of stiffness measures within low disease activity. Morning stiffness (MS) is reported in 44 to 80% of patients in low disease activity. A difference of 40 to 60 minutes in duration until maximum improvement is observed between active and inactive patients. Severity of MS might discriminate better between high and low disease activity compared to measurement of duration of MS.

CONCLUSIONS

There is insufficient data on measurement of stiffness in the spectrum of low disease activity or remission.

A novel multilayered multidisk oral tablet for chronotherapeutic drug delivery

A Multilayered Multidisk Tablet (MLMDT) comprising two drug-loaded disks enveloped by three drug-free barrier layers was developed for use in chronotherapeutic disorders, employing two model drugs, theophylline and diltiazem HCl. The MLMDT was designed to achieve two pulses of drug release separated by a lag phase. The polymer disk comprised hydroxyethylcellulose (HEC) and ethylcellulose (EC) granulated using an aqueous dispersion of EC. The polymeric barrier layers constituted a combination of pectin/Avicel (PBL) (1st barrier layer) and hydroxypropylmethylcellulose (HPMC) (HBL1 and HBL2) as the 2nd and 3rd barrier layers, respectively. Sodium bicarbonate was incorporated into the diltiazem-containing formulation for delayed drug release. Erosion and swelling studies confirmed the manner in which the drug was released with theophylline formulations exhibiting a maximum swelling of 97% and diltiazem containing formulations with a maximum swelling of 119%. FTIR spectra displayed no interactions between drugs and polymers. Molecular mechanics simulations were undertaken to predict the possible orientation of the polymer morphologies most likely affecting the MLMDT performance. The MLMDT provided two pulses of drug release, separated by a lag phase, and additionally it displayed desirable friability, hardness, and uniformity of mass indicating a stable formulation that may be a desirable candidate for chronotherapeutic drug delivery.

Delayed-release prednisone - a new approach to an old therapy

INTRODUCTION

Despite the widespread use of glucocorticoid (GC) treatment for inflammatory conditions, there remains a need to optimize use by improving efficacy and/or reducing adverse consequences. The most advanced approach, already licensed for clinical use, is delayed-release prednisone.

AREAS COVERED

Delayed-release prednisone consists of an inert outer coat containing an inner core of active drug (1, 2, or 5 mg) taken at bedtime (approximately 22:00 h). After a lag time of 4 - 6 h, the coat opens to release prednisone, at the appropriate time to counteract elevated nocturnal levels of pro-inflammatory cytokines associated with the circadian pattern of symptoms seen in rheumatoid arthritis (RA) and other inflammatory conditions. Clinical trials in RA have demonstrated the improved efficacy of delayed-release prednisone with respect to morning stiffness compared with conventional immediate-release prednisone tablets taken in the morning and compared with placebo in patients on disease-modifying antirheumatic treatment; the incidence of adverse events was similar to the comparator. Preliminary studies in polymyalgia rheumatica and asthma suggest that delayed-release prednisone may also have benefits in these conditions.

EXPERT OPINION

Delayed-release prednisone offers an effective way to improve the benefit:risk ratio of GC treatment for inflammatory conditions with circadian features.

Therapeutic applications of melatonin

Melatonin is a methoxyindole synthesized within the pineal gland. The hormone is secreted during the night and appears to play multiple roles within the human organism. The hormone contributes to the regulation of biological rhythms, may induce sleep, has strong antioxidant action and appears to contribute to the protection of the organism from carcinogenesis and neurodegenerative disorders. At a therapeutic level as well as in prevention, melatonin is used for the management of sleep disorders and jet lag, for the resynchronization of circadian rhythms in situations such as blindness and shift work, for its preventive action in the development of cancer, as additive therapy in cancer and as therapy for preventing the progression of Alzheimer's disease and other neurodegenerative disorders.

Adenosine A2A receptor and TNF-α regulate the circadian machinery of the human monocytic THP-1 cells

Morning stiffness and increased symptoms of inflammatory arthritis are among the most common manifestations of rheumatoid arthritis (RA). Tumor necrosis alpha (TNF-α), an important mediator of inflammation in RA, regulates the circadian expression of clock proteins, and adenosine A(2A) receptors (A(2A)R) mediate many of the anti-inflammatory and antirheumatic actions of methotrexate, the cornerstone drug in the treatment of RA. We found that A(2A)R activation and TNF-α activated the clock core loop of the human monocytic THP-1 cell line. We further observed that interleukin (IL)-10, but not IL-12, mRNA expression fluctuates in a circadian fashion and that TNF-α and A(2A)R stimulation combined increased IL-10 expression. Interestingly, TNF-α, but not CGS21680, dramatically inhibited IL-12 mRNA expression. The demonstration that A(2A)R and TNF-α regulate the intrinsic circadian clock in immune cells provides an explanation for both the pathologic changes in circadian rhythms in RA and for the adverse circadian effects of methotrexate, such as fatigue.

An agent-based model of cellular dynamics and circadian variability in human endotoxemia

As cellular variability and circadian rhythmicity play critical roles in immune and inflammatory responses, we present in this study an agent-based model of human endotoxemia to examine the interplay between circadian controls, cellular variability and stochastic dynamics of inflammatory cytokines. The model is qualitatively validated by its ability to reproduce circadian dynamics of inflammatory mediators and critical inflammatory responses after endotoxin administration in vivo. Novel computational concepts are proposed to characterize the cellular variability and synchronization of inflammatory cytokines in a population of heterogeneous leukocytes. Our results suggest that there is a decrease in cell-to-cell variability of inflammatory cytokines while their synchronization is increased after endotoxin challenge. Model parameters that are responsible for IκB production stimulated by NFκB activation and for the production of anti-inflammatory cytokines have large impacts on system behaviors. Additionally, examining time-dependent systemic responses revealed that the system is least vulnerable to endotoxin in the early morning and most vulnerable around midnight. Although much remains to be explored, proposed computational concepts and the model we have pioneered will provide important insights for future investigations and extensions, especially for single-cell studies to discover how cellular variability contributes to clinical implications.

Pharmacokinetics of modified-release prednisone tablets in healthy subjects and patients with rheumatoid arthritis

In rheumatoid arthritis (RA), nocturnal release of proinflammatory cytokines is not adequately counteracted by endogenous glucocorticoid and is associated with symptoms of morning stiffness and pain. Taking exogenous glucocorticoid during the night reduces morning stiffness significantly more than treatment at the conventional time in the morning, although waking to take tablets is unacceptable for patients. Modified-release prednisone tablets were developed to allow administration at bedtime for programmed delivery of glucocorticoid during the night. Single-center crossover studies were conducted, each in ≤24 healthy subjects, to compare the pharmacokinetics of a single 5-mg oral dose of modified-release prednisone and conventional prednisone, as well as the effect of food on bioavailability. There was no substantial difference in pharmacokinetic parameters of the formulations apart from the programmed delay in release of glucocorticoid from the modified-release tablets (C(max) 97%, AUC(0-∞) 101%, 90% confidence intervals within the requisite range for bioequivalence). Administration after a full or light meal did not affect pharmacokinetic characteristics, but bioavailability was reduced under fasted conditions. Pharmacokinetic evaluation in 9 patients with RA confirmed that modified-release prednisone tablets taken at bedtime (around 22:00 h) with or after an evening meal result in programmed release of glucocorticoid 4 to 6 hours after intake.

The RelB subunit of NFκB acts as a negative regulator of circadian gene expression

The circadian system controls a large array of physiological and metabolic functions. The molecular organization of the circadian clock is complex, involving various elements organized in feedback regulatory loops. Here we demonstrate that the RelB subunit of NFκB acts as a repressor of circadian transcription. RelB physically interacts with the circadian activator BMAL1 in the presence of CLOCK to repress circadian gene expression at the promoter of the clock-controlled gene Dbp. The repression is independent of the circadian negative regulator CRY. Notably, RelB -/- fibroblasts have profound alterations of circadian genes expression. These findings reveal a previously unforeseen function for RelB as an important regulator of the mammalian circadian system in fibroblasts.

Chronobiology and the treatment of rheumatoid arthritis

PURPOSE OF REVIEW

As circadian rhythms and biological signaling occur in a complex network with cyclical 24-h period interactions (chronobiology) between the central and the autonomic nervous systems, the endocrine glands and the immune system, this review will explore the involvement of this emerging network in the disease pathophysiology and management.

RECENT FINDINGS

Recent advances regarding nocturnal hormones such as melatonin and prolactin that activate the nighttime immune response, and the successive rise of cortisol that dowregulates the ongoing immune reactivity very early in the morning, will be discussed within the circadian neuroendocrine immune network. In addition, the role of sleep and the daily distribution of body energy, which are important factors for the homoeostatic regulation of circadian physiological/pathological processes of the immune network will be reviewed.In chronic immune/inflammatory conditions such as rheumatoid arthritis (RA), stiffness and functional disability are evident in the early morning hours as under the chronic stress of the disease the nighttime adrenal cortisol production becomes insufficient to inhibit ongoing nocturnal immune/inflammatory activity.

SUMMARY

Currently, the most advanced approach to optimizing the risk-benefit ratio for long-term glucocorticoid treatment in RA seems to be low-dose chronotherapy with modified nighttime release prednisone (release at 3 a.m.). A similar chronotherapeutical approach could also be effective with disease-modifying antirheumatic drugs such as methotrexate.

Disruption of rhythms of molecular clocks in primary synovial fibroblasts of patients with osteoarthritis and rheumatoid arthritis, role of IL-1β/TNF

Introduction

Circadian rhythms play an important role in the body and in single cells. Rhythms of molecular clocks have not been investigated in synovial fibroblasts (SF) of patients with osteoarthritis (OA) and rheumatoid arthritis (RA). The study was initiated to fill this gap and to study effects of interleukin (IL)-1β/tumor necrosis factor (TNF) on rhythmicity in synovial fibroblasts of RA and OA patients.

Methods

The presence of BMAL-1, CLOCK, Period 1 and Period 2 proteins in synovial tissue was investigated by immunofluorescence. The presence of mRNA of molecular clocks was studied during 72 h by qPCR. Characteristics of rhythms were studied with time series analysis.

Results

BMAL-1, CLOCK, Period 1 and Period 2 proteins were abundantly present in synovial tissue of OA, RA and controls. Receiving synovial tissue at different operation time points during the day (8:00 am to 4:00 pm) did not reveal a rhythm of BMAL-1 or Period 1 protein. In OASF and RASF, no typical rhythm curve of molecular clock mRNA was observed. Time series analysis identified a first peak between 2 and 18 hours after synchronization but a period was not detectable due to loss of rhythm. TNF inhibited mRNA of CLOCK, Period 1 and Period 2 in OASF, while IL-1β and TNF increased these factors in RASF. This was supported by dose-dependently increased levels in MH7A RA fibroblasts. In RASF, IL-1β and TNF shifted the first peak of BMAL-1 mRNA to later time points (8 h to 14 h).

Conclusion

Rhythmicity is not present in primary OASF and RASF, which is unexpected because fibroblasts usually demonstrate perfect rhythms during several days. This might lead to uncoupling of important cellular pathways.

Low-dose prednisone chronotherapy for rheumatoid arthritis: a randomised clinical trial (CAPRA-2)

OBJECTIVE

To assess the efficacy and safety of low-dose prednisone chronotherapy using a new modified-release (MR) formulation for the treatment of rheumatoid arthritis (RA).

METHODS

In this 12-week, double-blind, placebo-controlled study, patients with active RA (n=350) were randomised 2:1 to receive MR prednisone 5 mg or placebo once daily in the evening in addition to their existing RA disease-modifying antirheumatic drug (DMARD) treatment. The primary end point was the percentage of patients achieving a 20% improvement in RA signs and symptoms according to American College of Rheumatology criteria (ie, an ACR20 response) at week 12. Changes in morning pain, duration of morning stiffness, 28-joint Disease Activity Score and health-related quality of life were also assessed.

RESULTS

MR prednisone plus DMARD treatment produced higher response rates for ACR20 (48% vs 29%, p<0.001) and ACR50 (22% vs 10%, p<0.006) and a greater median relative reduction from baseline in morning stiffness (55% vs 35%, p<0.002) at week 12 than placebo plus DMARD treatment. Significantly greater reductions in severity of RA (Disease Activity Score 28) (p<0.001) and fatigue (Functional Assessment of Chronic Illness Therapy-Fatigue score) (p=0.003) as well as a greater improvement in physical function (36-item Short-Form Health Survey score) (p<0.001) were seen at week 12 for MR prednisone versus placebo. The incidence of adverse events was similar for MR prednisone (43%) and placebo (49%).

CONCLUSION

Low-dose MR prednisone added to existing DMARD treatment produced rapid and relevant improvements in RA signs and symptoms. CLINICALTRIALS.GOV, NUMBER: NCT00650078.