Non-inflammatory Causes of Pain in Patients with Rheumatoid Arthritis

Clinical Efficacy of Acupuncture Therapy Based on the Principles of Primary Point Selection, Local Point Selection, and Syndrome Differentiation in Rheumatoid Arthritis

OBJECTIVE

To evaluate the clinical efficacy of acupuncture treatment based on the principles of primary point selection, local point selection, and syndrome differentiation in patients with rheumatoid arthritis (RA).

METHODS

RA patients recruited from the rheumatology department of our hospital between January 2022 and January 2024 were randomly assigned to either the sham acupuncture group or the acupuncture group. The sham group received medication combined with sham acupuncture, while the acupuncture group received medication combined with acupuncture based on the principles above. Comparisons were made on Traditional Chinese Medicine (TCM) syndrome scores, quality of life, clinical symptoms, and inflammatory status after 4 weeks of treatment.

RESULTS

A total of 65 patients in the acupuncture group and 66 in the sham group were analyzed. The acupuncture group showed a substantially higher total effective rate than the sham group, underscoring a significant advantage in treatment efficacy (81.56% vs. 60.61%). After treatment, the reduction in TCM syndrome scores in the acupuncture group was greater by 1.16 compared to the sham group (95% CI: 0.21-2.12). Following treatment, both groups showed notable improvements, as shown by notable decreases in their Disease Activity Score for 28 joints and Health Assessment Questionnaire ratings. The acupuncture group reported significantly lower scores than the sham group (all p < 0.05). Additionally, rheumatoid factor, high-sensitivity C-reactive protein, and erythrocyte sedimentation rate levels were decreased in both groups. All of the results were statistically significant (all p < 0.05). However, the acupuncture group had significantly lower levels of these markers than the sham group. This suggests that acupuncture has a stronger therapeutic impact when treating illness.

CONCLUSION

Acupuncture treatment based on primary point selection, local point selection, and syndrome differentiation significantly alleviates clinical symptoms and inflammatory states in patients with RA, thereby improving quality of life.

Prevalence of complementary therapy use in patients with inflammatory arthritis: a cross-sectional study in China

This study aimed to evaluate the utilization of complementary and alternative medicine (CAM) among Chinese patients with inflammatory arthritis (IA), the types of CAM used, and the factors associated with its use. This cross-sectional study was conducted at the Department of Rheumatology and Immunology at the First Affiliated Hospital of Anhui Medical University. Data were collected from 503 IA patients using self-administered questionnaires and electronic medical records. Demographic, clinical, and disease activity data and pain, fatigue, emotion, and sleep quality assessments were analyzed. The study found that 50.3% of patients with IA used CAM, with herbal medicines and products being the most common therapies utilized by 74.3% of CAM users. CAM users reported significantly higher levels of fatigue, negative emotion states, and poorer sleep quality compared to non-users. Multivariate logistic regression analysis identified age, employment status, disease duration, IA family history, and disease activity as significant predictors of CAM use. This study revealed a high prevalence of CAM use among patients with IA in China. Healthcare professionals should enhance their understanding of CAM to inform and guide patients better and ensure the safe and effective integration of CAM therapies with conventional treatments.

Implications of nociceptor receptors and immune modulation: emerging therapeutic targets for autoimmune diseases

Chronic painful autoimmune disorders such as multiple sclerosis (MS), inflammatory bowel disease (IBD), and rheumatoid arthritis (RA) induce significant discomfort. They are defined by persistent inflammation and immune-mediated tissue injury. The activation and sensitisation of nociceptors, mutated in various disorders, are fundamental components contributing to the pain experienced in these conditions. Recent discoveries indicate that immunological mediators and nociceptive receptors interact functionally within peripheral and central sensitisation pathways, amplifying chronic pain. This research examines the involvement of nociceptors in rheumatoid arthritis, multiple sclerosis, and inflammatory bowel disease. It explores how immune cells and pro-inflammatory cytokines induce, sensitise and regulate various nociceptive receptors (P2X, TRPA1 and TRPV1). Finally, we address possible future directions with respect to the treatment of long-lasting effects on immunity, and what new drug targets could be pursued as well, in order to counteract such either neuro-immune interactions in conditions involving the immunological system. By studying nociceptive mechanisms across autoimmune illnesses, we want to identify shared pathways and activation of nociceptors specific to individual diseases. This will shed insight on potential therapies for managing pain associated with autoimmune diseases.

Factors Affecting Pain Intensity Among Korean Women With Rheumatoid Arthritis: A Cross-Sectional Analysis

This cross-sectional study investigated the factors affecting pain intensity among Korean women with rheumatoid arthritis (RA) (n = 246). Data included pain site and intensity, physical function, fatigue, medication attitudes, and learned helplessness (LH) from patient self-report, and Disease Activity Score 28 (DAS28) from chart review. The overall pain intensity was 3.59 out of 10, with a median of 3. The mean number of painful joints was 8.4, with the most commonly reported painful joint groups being the fingers, wrists, and knees. Higher DAS28, impaired physical function, eight or more painful joints, higher levels of fatigue, and higher levels of LH were significantly associated with pain intensity. Our results suggest that pain in women with RA is closely associated with cognitive or psychological variables such as fatigue and LH in addition to inflammation itself. For improved pain management, patients with RA should receive regular counseling to address their feelings of LH and fatigue.

The effects of sarilumab as monotherapy and in combination with non-methotrexate disease-modifying anti-rheumatic drugs on unacceptable pain in patients with rheumatoid arthritis: A post-hoc analysis of the HARUKA phase 3 study

OBJECTIVES

To investigate unacceptable pain [UP; visual analogue scale (VAS) >40 mm] and uncontrolled inflammation [C-reactive protein (CRP) ≥1.0 mg/dL] in patients with active rheumatoid arthritis (RA) receiving sarilumab (SAR) as monotherapy or in combination with non-methotrexate conventional synthetic disease-modifying antirheumatic drugs (SAR + csDMARDs).

METHODS

In the HARUKA Phase 3 study (NCT02373202), Japanese patients received either SAR monotherapy (n = 61) or SAR + csDMARDs (n = 30). In this post-hoc analysis, changes in the proportions of patients with/without UP and controlled/uncontrolled inflammation were assessed over 52 weeks.

RESULTS

At baseline, 80.3% (49/61) of patients receiving SAR monotherapy had UP and this proportion decreased with treatment to 55.9% (33/59) at Week 4 and 15.5% (9/58) at Week 52. The SAR + csDMARDs group achieved a reduction in UP from 73.3% (22/30) at baseline to 34.5% (10/29) at Week 4 and 0% (0/24) by Week 52. At baseline, 34.4% (21/61) and 50% (15/30) of patients had both UP and uncontrolled inflammation in the SAR monotherapy and SAR + csDMARDs groups; by Week 2, the proportions decreased to 6.6% (4/61) and 3.3% (1/30), respectively; and 0% in both groups by Week 52.

CONCLUSION

UP and inflammation were reduced in patients with active RA in Japan in both SAR monotherapy and SAR + csDMARDs treatment groups.

Utilising Hyperspectral Autofluorescence Imaging in the Objective Assessment of Disease State and Pain in Patients with Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a chronic inflammatory disease resulting in joint swelling and pain. Treatment options can be reliant on disease activity scores (DAS) incorporating patient global assessments, which are quantified via visual analogue scales (VAS). VAS can be subjective and not necessarily align with clinical symptoms, such as inflammation, resulting in a disconnect between the patient's and practitioners' experience. The development of more objective assessments of pain would enable a more targeted and personalised management of pain within individuals with RA and have the potential to improve the reliability of assessments in research. Using emerging light-based hyperspectral autofluorescence imaging (HAI) technology, we aimed to objectively differentiate disease and pain states based on the analysis of synovial tissue (ST) samples from RA patients. In total, 22 individuals with RA were dichotomised using the DAS in 28-joint counts (DAS-28) into an inactive (IA) or active disease (active-RA) group and then three sub-levels of pain (low, mid, high) based on VAS. HAI was performed on ST sections to identify and quantify the most prominent fluorophores. HAI fluorophore analysis revealed a distinct separation between the IA-RA and active-RA mid-VAS cohort, successfully determining disease state. Additionally, the separation between active-RA Mid-VAS and active RA High-VAS cohort suggests that HAI could be used to objectively separate individuals based on pain severity.

Intense symptoms of pain are associated with poor sleep, fibromyalgia, depression and sleep apnea in patients with rheumatoid arthritis and psoriatic arthritis. A register-based study

OBJECTIVES

To study whether poor sleep and comorbidities are associated with high symptom levels of patient-reported outcomes (PROs) pain, patient global assessment and fatigue in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA), in a nation-wide cross-sectional setting.

METHODS

Clinical data were extracted from The Finnish Rheumatology Quality Register between 1.2021 and 9.2022. Self-reported sleep was categorized as "good" (little/no difficulties) or "poor" (great difficulties/can't) sleep. Data concerning comorbidities were collected from national registers. Descriptive statistics were used. Regression analyses were applied to analyze independent associations of sleep status, comorbidities and disease activity with pain in RA and PsA, adjusting for age and sex.

RESULTS

Among 13,512 patients with RA, 6052 [mean (SD) age 62 (13), 71% female] had sleep status reported; in PsA 1861/3636 [age 55 (13), 48% female]. In RA, 5072 (84%) reported good and 980 (16%) poor sleep; the corresponding numbers in PsA were 1460 (78%) and 401 (22%). Median values for objective disease activity were low and similar in patients with poor sleep and good sleep in both diseases. Among patients with no swollen joints, the median values for PROs were approximately three times higher for patients with poor sleep vs. good sleep in both diagnoses (P<0.001). In regression analyses, "poor" sleep was independently associated with higher symptoms in pain [B (95%CI) 20 (18,22) in RA and 23 (19, 26) in PsA], followed by comorbid fibromyalgia, as well as depression in RA and sleep apnea in PsA.

CONCLUSION

"Poor" sleep quality and comorbidities are independently associated with pain. Patient's sleep status is important to know especially in patients with severe symptoms without objective disease activity.

Effect of sarilumab on unacceptable pain and inflammation control in Japanese patients with moderately-to-severely active rheumatoid arthritis: Post hoc analysis of a Phase III study (KAKEHASI)

OBJECTIVE

The aim of this study is to investigate the effects of sarilumab on unacceptable pain [UP; visual analogue scale (VAS) >40 mm] and inflammation in patients with moderately-to-severely active rheumatoid arthritis.

METHODS

In this post hoc analysis of the KAKEHASI study, 243 patients received methotrexate with sarilumab 150 or 200 mg or placebo every other week, over 52 weeks. The proportion of patients with UP and correlations of changes in pain VAS from baseline with uncontrolled inflammation (C-reactive protein ≥1 mg/dl) and disease activity indices were assessed.

RESULTS

Almost 80% of patients (192/243) had UP at baseline, including ∼60% of patients with uncontrolled inflammation. Among patients receiving sarilumab, inflammation decreased rapidly, with 90% of patients achieving controlled inflammation by Week 2, while 63.1% continued to have UP. The proportion of patients with UP further decreased by Week 16 (28.5%, sarilumab vs. 64.0%, placebo). By Week 52, only ∼10% of patients had UP. Changes in pain VAS correlated with most disease activity indices and patient-reported outcomes. However, marked correlations between changes in pain VAS and C-reactive protein were observed only at Week 16.

CONCLUSION

Sarilumab treatment reduced UP and inflammation in Japanese patients with rheumatoid arthritis.

Identification of novel TACE inhibitors using DNN based- virtual screening, molecular dynamics and biological evaluation

Rheumatoid Arthritis (RA) is a well-known autoimmune inflammatory disease, distressing roughly 1% of the adult population throughout the globe. Many studies have suggested that overexpression of TNF-α, a pro-inflammatory cytokine, is responsible for the progression of RA. Furthermore, inhibition of the shedding rate of TNF-α is regulated by the TACE (TNF-α converting enzyme) protein and, hence is considered as an important therapeutic target for the prevention of progressive synovial joint destruction in rheumatoid arthritis. In the present study, we have proposed a deep neural network (DNN)-based workflow for the virtual screening of compounds towards the identification of potential inhibitors against the TACE proteins. Subsequently, a set of compounds were shortlisted, based on the molecular docking and subjected to the biological evaluation to validate the inhibitory activities of the screened compounds, determine the practical applicability of the DNN-based model, and strengthen the hypothesis. Out of seven, three compounds (BTB10246, BTB10247, and BTB10245) showed significant inhibition at 10 µM and 0.1 µM concentration. These three compounds also showed a stable and significant interaction potential against the TACE protein as compared with the re-docked complex system and can serve as a novel scaffold for further design of new molecules with improved inhibitory activities against TACE.Communicated by Ramaswamy H. Sarma.

Impact of filgotinib on pain control in the phase 3 FINCH studies

OBJECTIVE

This post hoc analysis of the FINCH 1-3 (NCT02889796, NCT02873936 and NCT02886728) studies assessed specific effects of filgotinib on pain control and their relationship with other aspects of efficacy in patients with rheumatoid arthritis (RA).

METHODS

Assessments included: residual pain responses of ≤10 and ≤20 mm on a 100 mm visual analogue scale (VAS); the proportion of patients who achieved VAS pain responses in addition to remission or low disease activity by Disease Activity Score-28 with C-reactive protein (DAS28-CRP) or Clinical Disease Activity Index (CDAI) criteria.

RESULTS

Across studies, filgotinib reduced pain from week 2, with responses sustained throughout the studies. In FINCH 1, at week 24, 35.8%, 25.0%, 24.6% and 11.6% of patients in the filgotinib 200 mg, filgotinib 100 mg, adalimumab and placebo arms (each plus methotrexate) achieved VAS pain ≤20 mm in addition to DAS28-CRP remission; 26.3%, 17.9%, 17.2% and 7.6% achieved VAS pain ≤10 mm in addition to DAS28-CRP remission. A similar pattern was seen for CDAI remission. Time during which VAS pain was ≤10 or ≤20 mm was longest with filgotinib 200 mg and comparable between adalimumab and filgotinib 100 mg. Similar findings were reported for filgotinib in FINCH 2 and 3.

CONCLUSION

In all RA populations studied, pain improvements occurred from week 2 and were sustained over time. In FINCH 1, filgotinib 100 mg provided similar pain amelioration to adalimumab, whereas filgotinib 200 mg resulted in greater pain improvement and higher proportion of patients with residual pain ≤10 or ≤20 mm and meeting DAS28-CRP remission criteria.

"Inflammatory or non-inflammatory pain in inflammatory arthritis - How to differentiate it?"

Pain is a significant issue in rheumatoid arthritis (RA) and psoriatic arthritis (PSA) and can have a negative impact on patients' quality of life. Despite optimal control of inflammatory disease, residual chronic pain remains a major unmet medical need in RA. Pain in RA can be secondary to inflammation but can also generate neuroendocrine responses that initiate neurogenic inflammation and enhance cytokine release, leading to persistent hyperalgesia. In addition to well-known cytokines such as TNFα and IL-6, other cytokines and the JAK-STAT pathway play a role in pain modulation and inflammation. The development of chronic pain in RA involves processes beyond inflammation or structural damage. Residual pain is often observed in patients even after achieving remission or low disease activity, suggesting the involvement of non-inflammatory and central sensitization mechanisms. Moreover, fibromyalgia syndrome (FMS) is prevalent in RA patients and may contribute to persistent pain. Factors such as depression, sleep disturbance, and pro-inflammatory cytokines may contribute to the development of fibromyalgia in RA. It is essential to identify and diagnose concomitant FMS in RA patients to better manage their symptoms. Further research is needed to unravel the complexities of pain in RA. Finally, recent studies have shown that JAK inhibitors effectively reduce residual pain in RA patients, suggesting pain-reducing effects independent of their anti-inflammatory properties.

Rheumatoid arthritis molecular targets and their importance to flavonoid-based therapy

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune, inflammatory, and systemic condition that primarily affects the synovial joints and adjacent tissues, including bone, muscle, and tendons. The World Health Organization recognizes RA as one of the most prevalent chronic inflammatory diseases. In the last decade, there was an expansion on the available RA therapeutic options which aimed to improve patient's quality of life. Despite the extensive research and the emergence of new therapeutic approaches and drugs, there are still significant unwanted side effects associated to these drugs and still a vast number of patients that do not respond positively to the existing therapeutic strategies. Over the years, several references to the use of flavonoids in the quest for new treatments for RA have emerged. This review aimed to summarize the existing literature about the flavonoids' effects on the major pathogenic/molecular targets of RA and their potential use as lead compounds for the development of new effective molecules for RA treatment. It is demonstrated that flavonoids can modulate various players in synovial inflammation, regulate immune cell function, decrease synoviocytes proliferation and balance the apoptotic process, decrease angiogenesis, and stop/prevent bone and cartilage degradation, which are all dominant features of RA. Although further investigation is necessary to determine the effectiveness of flavonoids in humans, the available data from in vitro and in vivo models suggest their potential as new disease-modifying anti-rheumatic drugs. This review highlights the use of flavonoids as a promising avenue for future research in the treatment of RA.

Factors associated with mental illness in patients with rheumatoid arthritis initiating b/ts DMARDs: A population-based study

AIM

Mental health is an essential issue in patients with rheumatoid arthritis (RA) but remains unclear among those receiving biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). We aim to assess the incidence and factors associated with mental illness among patients with RA who underwent b/tsDMARD therapy.

METHOD

We used Taiwan's National Health Insurance Research Database for the period 2001-2020 to identify patients with RA receiving b/tsDMARDs. The primary outcome was newly developed mental illness, including anxiety and mood disorders. We performed a Cox regression analysis to determine factors associated with mental illness and presented as hazard ratios (HR) with 95% confidence interval (CI).

RESULTS

We enrolled 10 852 patients, with 7854 patients receiving tumor necrosis factors inhibitors (TNFi), 1693 patients receiving non-TNFi bDMARDs, and 1305 patients treated with tsDMARD. We found that 13.62% of enrolled patients developed mental illness, with an incidence rate of 4054 per 100 000 person-year. Those receiving tocilizumab (aHR 0.64, 95% CI: 0.51-0.82), abatacept (aHR 0.69, 95% CI: 0.55-0.86), or tsDMARDs (aHR 0.58, 95% CI: 0.47-0.73) had a lower risk of mental illness compared with those receiving TNFi. We also found that old age, low income, diabetes mellitus, use of cyclosporine, and use of steroids were associated with incident mental illness.

CONCLUSION

This population-based study investigated the incidence and factors associated with mental illness among patients with RA receiving b/tsDMARDs. Our findings highlight the need for vigilance with respect to the possibility of mental illness in patients with RA.

Test-Retest Reliability of the Generalized Pain Questionnaire in Patients with Rheumatoid Arthritis and Preliminary Reference Values for Non-Clinical and Several Clinical Samples

Introduction

Generalized pain hypersensitivity is a characteristic feature in many different types of chronic pain. Recently, a 7-item self-reported Generalized Pain Questionnaire (GPQ) was developed to evaluate the presence and severity of generalized pain hypersensitivity in chronic pain patients. Here, we evaluate the test-retest reliability of the GPQ and report on preliminary reference values for various patient groups and healthy subjects.

Methods

Eighty-five patients diagnosed with Rheumatoid Arthritis (RA) completed the GPQ twice over a 2-week interval. Relative and absolute indicators of reliability were determined using data of 69 patients (81.2% retest response rate). Using readily available datasets, preliminary reference data were established in two nonclinical populations (NCP1; N = 30 and NCP2; N = 111), and for patients diagnosed with RA (N = 114), gout (N = 97), fibromyalgia (N=98), or neuropathy (N = 25), or participants in a pain rehabilitation program (N = 33).

Results

Total GPQ scores had an ICC of 0.78 (95% CI: 0.67 to 0.86). While no systematic or proportional differences were found for the GPQ total score; two (near-)significant systematic differences were observed for the individual questions. The standard error of measurement and minimal detectable change were 2.22 and 6.2, respectively. Mean ± SD scores were found to be 0.8 ± 1.2 (NCP1), 4.0 ± 4.6 (NCP2), 6.4 ± 5.5 (Gout), 6.5 ± 5.1 (RA), 8.1 ± 4.5 (Neuropathy), 13.6 ± 4.0 (Rehabilitation) and 16.0 ± 5.0 (Fibromyalgia).

Discussion

This study shows that the GPQ has acceptable reliability to be used as a tool to evaluate the presence and intensity of generalized pain hypersensitivity. The absolute measures of reliability and the preliminary reference values reported here aid in the interpretation of future studies with the GPQ.

The effects of Phycocyanobilin on experimental arthritis involve the reduction in nociception and synovial neutrophil infiltration, inhibition of cytokine production, and modulation of the neuronal proteome

Introduction

The antinociceptive and pharmacological activities of C-Phycocyanin (C-PC) and Phycocyanobilin (PCB) in the context of inflammatory arthritis remain unexplored so far. In the present study, we aimed to assess the protective actions of these compounds in an experimental mice model that replicates key aspects of human rheumatoid arthritis.

Methods

Antigen-induced arthritis (AIA) was established by intradermal injection of methylated bovine serum albumin in C57BL/6 mice, and one hour before the antigen challenge, either C-PC (2, 4, or 8 mg/kg) or PCB (0.1 or 1 mg/kg) were administered intraperitoneally. Proteome profiling was also conducted on glutamate-exposed SH-SY5Y neuronal cells to evaluate the PCB impact on this key signaling pathway associated with nociceptive neuronal sensitization.

Results and discussion

C-PC and PCB notably ameliorated hypernociception, synovial neutrophil infiltration, myeloperoxidase activity, and the periarticular cytokine concentration of IFN-γ, TNF-α, IL-17A, and IL-4 dose-dependently in AIA mice. In addition, 1 mg/kg PCB downregulated the gene expression for T-bet, RORγ, and IFN-γ in the popliteal lymph nodes, accompanied by a significant reduction in the pathological arthritic index of AIA mice. Noteworthy, neuronal proteome analysis revealed that PCB modulated biological processes such as pain, inflammation, and glutamatergic transmission, all of which are involved in arthritic pathology.

Conclusions

These findings demonstrate the remarkable efficacy of PCB in alleviating the nociception and inflammation in the AIA mice model and shed new light on mechanisms underlying the PCB modulation of the neuronal proteome. This research work opens a new avenue to explore the translational potential of PCB in developing a therapeutic strategy for inflammation and pain in rheumatoid arthritis.

Association of Sleep Disturbance With Catastrophizing and Knee Pain: Data From the Osteoarthritis Initiative

OBJECTIVE

To investigate the relationship between sleep disturbance, catastrophizing, and knee pain in middle-aged and older individuals.

METHODS

Data from the Osteoarthritis Initiative cohort from months 48 to 96 were used, where month 48 was treated as baseline. Knee pain (Western Ontario and McMaster Universities Osteoarthritis Index pain scale score ≥5 [range 0-20]), catastrophizing (extracted from Coping Strategies Questionnaire score ≥3 [range 0-6]), and sleep quality (extracted from Center for Epidemiologic Studies Depression Scale [range 1-4]) were assessed annually. We described the association of sleep disturbance with the presence and risk of knee pain and catastrophizing. The mediation effect of knee pain and catastrophizing on the sleep-catastrophizing and sleep-pain association was evaluated, respectively.

RESULTS

Catastrophizing and knee pain were reported in 346 (10%) and 917 (24%) of the 3,813 participants (mean 64.9 years, 58% female) at baseline. Participants with worse sleep disturbance were more likely to have knee pain (prevalence ratio [PR] 1.4-2.0, P for trend <0.001) and catastrophizing (PR 1.4-3.1, P for trend <0.001). Sleep disturbance at baseline predicted the risk of knee pain (risk ratio [RR] 1.1, P for trend <0.001) and catastrophizing (RR 1.2-1.7, P for trend <0.001) during follow-up. No statistically significant interactions between sleep disturbance and knee pain or catastrophizing were observed. Knee pain and catastrophizing mediated the sleep-catastrophizing and sleep-pain association, respectively, at baseline, and knee pain negatively mediated the sleep-catastrophizing association longitudinally.

CONCLUSION

Sleep disturbance was associated with the presence and risk of catastrophizing and knee pain. Sleep interventions may have a universal and independent effect in preventing incident knee pain.

Further evaluation of inflammatory and non-inflammatory aspects of pain in rheumatoid arthritis patients

Objective

A high discrepancy between the number of tender and swollen joints (e.g. ΔTSJ ≥ 7) has previously been used as an indication for the presence of changes in central mechanisms in patients with moderate-to-high disease activity. In this study, we explored whether the ΔTSJ can also be used to obtain insights into the underlying pain mechanisms in patients with on average well-controlled disease activity.

Methods

A 2 year retrospective analysis of routinely obtained 28-joint DAS (DAS28) components was performed on 45 patients with low inflammatory activity at the group level. All patients underwent pressure pain threshold (PPT) and electrical pain threshold (EPT) measurements and completed four self-report questionnaires [short-form 36 (SF-36v2); central sensitization inventory (CSI); generalized pain questionnaire (GPQ); and the pain catastrophizing scale (PCS)].

Results

Patients with a ΔTSJ ≥ 3 at least once in the past 2 years showed significantly lower EPT and PPT values and higher levels of pain and disability on the SF-36v2 compared with the ΔTSJ < 3 group. Furthermore, GPQ scores were significantly higher in those with ΔTSJ ≥ 3, while CSI and PCS scores were similar.

Conclusion

These findings suggest that in patients in the ΔTSJ ≥ 3 group, mechanisms other than inflammation (only) underlie the pain. Moreover, our findings suggest that among the multiple potential underlying psychological mechanisms, pain catastrophizing (as measured by the PCS) and psychological hypervigilance (as measured by the CSI) do not play an important role. These findings could be useful in the clinical management of the patient. Depending on the dominant mechanism underlying the (persistent) pain, patients might respond differently to treatment.

Disproportionate articular pain is a frequent phenomenon in rheumatoid arthritis and responds to treatment with sarilumab

OBJECTIVES

In some patients with RA, joint pain is more severe than expected based on the amount of joint swelling [referred to as disproportionate articular pain (DP)]. We assessed DP prevalence and the effects of sarilumab, an IL-6 inhibitor, on DP.

METHODS

Data from RA patients treated with placebo or 200 mg sarilumab in the phase 3 randomized controlled trials (RCTs) MOBILITY and TARGET, adalimumab 40 mg or sarilumab 200 mg in the phase 3 RCT MONARCH and sarilumab 200 mg in open-label extensions (OLEs) were used. DP was defined as an excess tender 28-joint count (TJC28) over swollen 28-joint count (SJC28) of ≥7 (TJC28 - SJC28 ≥ 7). Treatment response and disease activity were determined for patients with and without DP.

RESULTS

Of 1531 sarilumab 200 mg patients from RCTs, 353 (23%) had baseline DP. On average, patients with DP had higher 28-joint DAS using CRP (DAS28-CRP) and pain scores than patients without DP, whereas CRP levels were similar. After 12 and 24 weeks, patients with baseline DP treated with sarilumab were more likely to be DP-free than those treated with placebo or adalimumab. In RCTs, more sarilumab-treated patients achieved low disease activity vs comparators, regardless of baseline DP status. In OLEs, patients were more likely to lose rather than gain DP status.

CONCLUSION

About one-quarter of patients with RA experienced DP, which responded well to sarilumab. These data support the concept that other mechanisms (potentially mediated via IL-6) in addition to inflammation may contribute to DP in RA.

TRIAL REGISTRATIONS

NCT01061736, NCT02332590, NCT01709578, NCT01146652.

Pain in the joints and beyond; the challenge of rheumatoid arthritis

Pain is a common and often debilitating symptom for people living with rheumatoid arthritis. Although pain is a generic feature of inflammation and often improves with successful treatment that targets inflammatory pathways, pain experience can persist. Emerging data suggest that the magnitude of pain relief might vary according to the therapeutic target of pharmacological intervention within the inflammatory cascade. Both inflammatory and non-inflammatory causes contribute to the pain experience, which depends on tissue origin, peripheral sensory mechanisms and their transmission, integration, and interpretation within the nervous system. Contemporary neuroimaging is transforming our understanding of these mechanisms and the role of sensory, emotional, and cognitive contributions to the experience of pain. This understanding paves the way for therapeutic approaches that recognise the existence of multiple, cognitively driven, supraspinal mechanisms for pain modulation and could complement pharmacological inflammation suppression. Such approaches include neuropsychological interventions that have the potential to modify human brain cortical structure and reduce suffering that is often associated with pain experience.

Effects of Aquatic Exercises for Women with Rheumatoid Arthritis: A 12-Week Intervention in a Quasi-Experimental Study with Pain as a Mediator of Depression

BACKGROUND

Rheumatoid arthritis (RA) is characterized by low physical fitness, pain, and depression. The present study aimed to examine the effects of a supervised aquatic exercise program on physical fitness, depression, and pain in women with RA and determine whether decreases in pain mediate depression.

METHODS

Forty-three women with RA, divided into an experimental group (EG; n = 21) and a control group (CG; n = 23), participated in a 12-week exercise program. Treatment effects were calculated via standardized difference or effect size (ES) using ANCOVA adjusted for baseline values (ES, 95% confidence interval (CI)). A simple panel of mediation was executed to determine whether changes in pain mediated improvements in depression after controlling for confounding variables, such as age, physical activity, and body mass index (BMI).

RESULTS

The aquatic exercise program had trivial and small effects on physical fitness, large effects on pain, and moderate effects on depression. The mediation model confirmed the indirect effect of pain on the decrease of depression in the participants of the aquatic exercise program.

CONCLUSIONS

Participants with RA in the aquatic exercise program experienced improvements in physical fitness, depression, and joint pain. Moreover, the improvements in joint pain mediated improvements in depression.

Pain Sensitization as a Potential Mediator of the Relationship Between Sleep Disturbance and Subsequent Pain in Rheumatoid Arthritis

OBJECTIVE

Many patients with rheumatoid arthritis (RA) experience sleep disturbances, commonly attributed to joint pain. Sleep disturbances could also influence pain. One mechanism may be through dysregulated pain processing, manifested by enhanced pain sensitivity. The present study was undertaken to examine the role of pain sensitization, measured by quantitative sensory testing (QST), as a mediator in the pathway of sleep disturbance leading to subsequent pain.

METHODS

We used longitudinal data from 221 patients with active RA who were followed for 12 weeks after initiating a disease-modifying antirheumatic drug. Baseline QST included pressure pain thresholds at articular (wrists, knees) and nonarticular (trapezius, thumbnails) sites, temporal summation (TS) at the wrist and forearm, and conditioned pain modulation (CPM). Baseline sleep disturbance and subsequent pain intensity were assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS). We evaluated correlations between sleep disturbance, QSTs, and subsequent pain intensity. Mediation analyses separately assessed each QST as a mediator, adjusting for baseline confounding factors.

RESULTS

Sleep disturbance was correlated with all QST measures except wrist TS and CPM. Sleep disturbance significantly predicted subsequent pain (coefficient for a meaningful increase of 5 units in sleep disturbance = 0.32 (95% confidence interval 0.11, 0.50) in multiple regression. QST mediated 10-19% of this effect.

CONCLUSION

Pain sensitization may be one mechanism through which sleep disturbance contributes to pain. The small magnitude of association indicates that unmeasured pathways may contribute to this relationship. Intervention studies are needed to establish causality and determine whether improving sleep can improve pain in patients with RA.

The effects of Reiki and hand massage on pain and fatigue in patients with rheumatoid arthritis

OBJECTIVE

The present study was conducted in order to determine the effects of Reiki and hand massage on the pain and fatigue of patients with rheumatoid arthritis.

METHODS

This study having a randomized controlled experimental design was carried out involving 105 individuals (35 in Reiki, 37 in hand massage, and 33 in control). Study data were collected between July 2020 and December 2021 by using a personal information form, Visual Analog Scale, and Piper Fatigue Scale.

RESULTS

The mean pain score and the fatigue severity of patients decreased after Reiki and hand massage interventions and the difference was found to be statistically significant (p < 0.05). Reiki and hand massage reduced the pain and fatigue levels of patients having rheumatoid arthritis.

CONCLUSION

It is recommended to use Reiki and hand massage in managing the symptoms and providing patients with care.

Identification of Multimorbidity Patterns in Rheumatoid Arthritis Through Machine Learning

OBJECTIVE

Recognizing that the interrelationships between chronic conditions that complicate rheumatoid arthritis (RA) are poorly understood, we aimed to identify patterns of multimorbidity and to define their prevalence in RA through machine learning.

METHODS

We constructed RA and age- and sex-matched (1:1) non-RA cohorts within a large commercial insurance database (MarketScan) and the Veterans Health Administration (VHA). Chronic conditions (n = 44) were identified from diagnosis codes from outpatient and inpatient encounters. Exploratory factor analysis was performed separately in both databases, stratified by RA diagnosis and sex, to identify multimorbidity patterns. The association of RA with different multimorbidity patterns was determined using conditional logistic regression.

RESULTS

We studied 226,850 patients in MarketScan (76% female) and 120,780 patients in the VHA (89% male). The primary multimorbidity patterns identified were characterized by the presence of cardiopulmonary, cardiometabolic, and mental health and chronic pain disorders. Multimorbidity patterns were similar between RA and non-RA patients, female and male patients, and patients in MarketScan and the VHA. RA patients had higher odds of each multimorbidity pattern (odds ratios [ORs] 1.17-2.96), with mental health and chronic pain disorders being the multimorbidity pattern most strongly associated with RA (ORs 2.07-2.96).

CONCLUSION

Cardiopulmonary, cardiometabolic, and mental health and chronic pain disorders represent predominant multimorbidity patterns, each of which is overrepresented in RA. The identification of multimorbidity patterns occurring more frequently in RA is an important first step in progressing toward a holistic approach to RA management and warrants assessment of their clinical and predictive utility.

Predictive model to identify multiple failure to biological therapy in patients with rheumatoid arthritis

Background:

Despite advances in the treatment of rheumatoid arthritis (RA) and the wide range of therapies available, there is a percentage of patients whose treatment presents a challenge for clinicians due to lack of response to multiple biologic and target-specific disease-modifying antirheumatic drugs (b/tsDMARDs).

Objective:

To develop and validate an algorithm to predict multiple failure to biological therapy in patients with RA.

Design:

Observational retrospective study involving subjects from a cohort of patients with RA receiving b/tsDMARDs.

Methods:

Based on the number of prior failures to b/tsDMARDs, patients were classified as either multi-refractory (MR) or non-refractory (NR). Patient characteristics were considered in the statistical analysis to design the predictive model, selecting those variables with a predictive capability. A decision algorithm known as ‘classification and regression tree’ (CART) was developed to create a prediction model of multi-drug resistance. Performance of the prediction algorithm was evaluated in an external independent cohort using area under the curve (AUC).

Results:

A total of 136 patients were included: 51 MR and 85 NR. The CART model was able to predict multiple failures to b/tsDMARDs using disease activity score-28 (DAS-28) values at 6 months after the start time of the initial b/tsDMARD, as well as DAS-28 improvement in the first 6 months and baseline DAS-28. The CART model showed a capability to correctly classify 94.1% NR and 87.5% MR patients with a sensitivity = 0.88, a specificity = 0.94, and an AUC = 0.89 (95% CI: 0.74–1.00). In the external validation cohort, 35 MR and 47 NR patients were included. The AUC value for the CART model in this cohort was 0.82 (95% CI: 0.73–0.9).

Conclusion:

Our model correctly classified NR and MR patients based on simple measurements available in routine clinical practice, which provides the possibility to characterize and individualize patient treatments during early stages.

Acute effects of exercise on pain symptoms, clinical inflammatory markers and inflammatory cytokines in people with rheumatoid arthritis: a systematic literature review

Background

Exercise is advocated in the treatment of rheumatoid arthritis (RA). However, uncertainty around the acute effects of exercise on pain and inflammation may be stopping people with RA from exercising more regularly.

Objectives

To determine the acute effects of exercise on pain symptoms, clinical inflammatory markers, and inflammatory cytokines in RA.

Design

A systematic review of the literature.

Data sources and methods

Five databases were searched (PubMed, Cochrane Library, CINAHL, Scopus and SPORTDiscus); inclusion criteria were studies with acute exercise, a definite diagnosis of RA and disease characteristics assessed by clinical function (i.e., disease activity score, health assessment questionnaire and self-reported pain), clinical markers associated with inflammation (i.e., c-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)), and inflammatory cytokines (i.e., interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α)).

Results

From a total of 1544 articles, initial screening and full text assessment left 11 studies meeting the inclusion criteria. A total of 274 people were included in the studies (RA = 186; control = 88). Acute bouts of aerobic, resistance, and combined aerobic and resistance exercise did not appear to exacerbate pain symptoms in people with RA.

Conclusion

Post-exercise responses for pain, clinical inflammatory markers and inflammatory cytokines were not different between people with or without RA. Exercise prescription was variable between studies, which limited between-study comparisons. Therefore, future investigations in people with RA are warranted, which combine different exercise modes and intensities to examine acute effects on pain symptoms and inflammatory markers.

Registration

The PROSPERO international prospective register of systematic reviews - CRD42018091155.

Metabolomics in rheumatoid arthritis: Advances and review

Rheumatoid arthritis (RA) is an autoimmune disease accompanied by metabolic alterations. The metabolic profiles of patients with RA can be determined using targeted and non-targeted metabolomics technology. Metabolic changes in glucose, lipid, and amino acid levels are involved in glycolysis, the tricarboxylic acid cycle, the pentose phosphate pathway, the arachidonic acid metabolic pathway, and amino acid metabolism. These alterations in metabolic pathways and metabolites can fulfill bio-energetic requirements, promote cell proliferation, drive inflammatory mediator secretion, mediate leukocyte infiltration, induce joint destruction and muscle atrophy, and regulate cell proliferation, which may reflect the etiologies of RA. Differential metabolites can be used as biomarkers for the diagnosis, prognosis, and risk prediction, improving the specificity and accuracy of diagnostics and prognosis prediction. Additionally, metabolic changes associated with therapeutic responses can improve the understanding of drug mechanism. Metabolic homeostasis and regulation are new therapeutic strategies for RA. In this review, we provide a comprehensive overview of advances in metabolomics for RA.

Antibody-induced pain-like behavior and bone erosion: links to subclinical inflammation, osteoclast activity, and acid-sensing ion channel 3-dependent sensitization

ABSTRACT

Several bone conditions, eg, bone cancer, osteoporosis, and rheumatoid arthritis (RA), are associated with a risk of developing persistent pain. Increased osteoclast activity is often the hallmark of these bony pathologies and not only leads to bone remodeling but is also a source of pronociceptive factors that sensitize the bone-innervating nociceptors. Although historically bone loss in RA has been believed to be a consequence of inflammation, both bone erosion and pain can occur years before the symptom onset. Here, we have addressed the disconnection between inflammation, pain, and bone erosion by using a combination of 2 monoclonal antibodies isolated from B cells of patients with RA. We have found that mice injected with B02/B09 monoclonal antibodies (mAbs) developed a long-lasting mechanical hypersensitivity that was accompanied by bone erosion in the absence of joint edema or synovitis. Intriguingly, we have noted a lack of analgesic effect of naproxen and a moderate elevation of few inflammatory factors in the ankle joints suggesting that B02/B09-induced pain-like behavior does not depend on inflammatory processes. By contrast, we found that inhibiting osteoclast activity and acid-sensing ion channel 3 signaling prevented the development of B02/B09-mediated mechanical hypersensitivity. Moreover, we have identified secretory phospholipase A2 and lysophosphatidylcholine 16:0 as critical components of B02/B09-induced pain-like behavior and shown that treatment with a secretory phospholipase A2 inhibitor reversed B02/B09-induced mechanical hypersensitivity and bone erosion. Taken together, our study suggests a potential link between bone erosion and pain in a state of subclinical inflammation and offers a step forward in understanding the mechanisms of bone pain in diseases such as RA.

Potential Role of Yoga Intervention in the Management of Chronic Non-malignant Pain

Pain is an unpleasant and upsetting experience. Persistent pain has an impact on an individual's quality of life which causes stress and mood disorders. There are currently no pain-relieving techniques available that can eliminate pain and offer relief without causing any adverse effects. These factors draw attention to traditional treatments like yoga and meditation, which can reduce biological stress and hence increase immunity, as well as alleviate the psychological and emotional suffering produced by pain. Yoga reduces the stress response and the pain cascade via the downregulation of the hypothalamus-pituitary-adrenal (HPA) axis and vagal stimulation. Yoga is a cost-effective growing health practice that, unlike pharmaceuticals, has no side effects and can help patients stay in remission for longer periods of time with fewer relapses. Yoga not only reduces stress and depression severity but also improves functional status and reduces pain perception. This article highlights the impact of yoga on pain management and on a malfunctioning immune system, which leads to improved health, pain reduction, disease management, and improvement in overall quality of life.

Janus kinase inhibitors in immunoinflammatory diseases: 10 years of clinical practice in rheumatology

Despite great advances in the diagnosis and treatment of Immune-mediated inflammatory diseases (IMIDs), which have led to a significant improvement in the prognosis in many patients, the central medical problems of this pathology – restoring the quality of life and reducing mortality to the population level – are far from being resolved. This served as a powerful stimulus for the study of new approaches to the pharmacotherapy of IMIDs, one of which is associated with the discovery of targets for small-molecule therapeutics that inhibit intracellular “signaling” molecules JAKs (Janus kinases). The current achievements, trends and recommendations regarding the use of JAK inhibitors in the treatment of IMIDs and also in the hyper-response phase of COVID-19 are reviewed.

Effect of upadacitinib on reducing pain in patients with active psoriatic arthritis or ankylosing spondylitis: post hoc analysis of three randomised clinical trials

Objective

Evaluate the effect of upadacitinib on pain outcomes in patients with active psoriatic arthritis (PsA) or ankylosing spondylitis (AS) across 3 randomised trials (SELECT-PsA 1 and 2 for PsA; SELECT-AXIS 1 for AS).

Methods

Patients were randomised to upadacitinib 15 mg once daily or placebo (all 3 studies), or adalimumab 40 mg every other week (SELECT-PsA 1 only). Pain outcomes included proportion of patients achieving ≥30%, ≥50% and ≥70% reduction from baseline in patient global assessment of pain and other end points.

Results

A higher proportion of patients receiving upadacitinib versus placebo achieved ≥30%, ≥50% and ≥70% reduction in pain end points as early as week 2; these improvements with upadacitinib were generally sustained or increased through year 1 (PsA 1/2 studies: 64%/48%, 58%/42% and 38%/22%, respectively; SELECT-AXIS 1 study: 76%, 72% and 54%). Results were similar with adalimumab in PsA 1 (59%, 49% and 32%). Patients who switched from placebo to upadacitinib 15 mg were able to reach a similar level of improvement as the continuous upadacitinib groups by year 1 (PsA 1/2 studies: 46%–60%, 35%–49% and 15%–34%; AS study: 83%, 72% and 46%). Results were similar with other pain end points.

Conclusion

Rapid and sustained improvements in pain outcomes across several end points were consistently shown with upadacitinib over 1 year in patients with active PsA or AS who had either inadequate response to prior non-biologic or biologic disease-modifying antirheumatic drugs (PsA studies) or were biologic-naïve with inadequate response to non-steroidal anti-inflammatory drugs (AS study).

Distinct aberrations in cerebral pain processing differentiating patients with fibromyalgia from patients with rheumatoid arthritis

ABSTRACT

The current study used functional magnetic resonance imaging to directly compare disease-relevant cerebral pain processing in well-characterized patient cohorts of fibromyalgia (FM, nociplastic pain) and rheumatoid arthritis (RA, nociceptive pain). Secondary aims were to identify pain-related cerebral alterations related to the severity of clinical symptoms such as pain intensity, depression, and anxiety. Twenty-six patients with FM (without RA-comorbidity) and 31 patients with RA (without FM-comorbidity) underwent functional magnetic resonance imaging while stimulated with subjectively calibrated painful pressures corresponding to a pain sensation of 50 mm on a 100-mm visual analogue scale. Stimulation sites were at the most inflamed proximal interphalangeal joint in the left hand in patients with RA and the left thumbnail in patients with FM, 2 sites that have previously been shown to yield the same brain activation in healthy controls. The current results revealed disease-distinct differences during pain modulation in RA and FM. Specifically, in response to painful stimulation, patients with FM compared to patients with RA exhibited increased brain activation in bilateral inferior parietal lobe (IPL), left inferior frontal gyrus (IFG)/ventrolateral prefrontal cortex (vlPFC) encapsulating left dorsolateral prefrontal cortex, and right IFG/vlPFC. However, patients with RA compared to patients with FM exhibited increased functional connectivity (during painful stimulation) between right and left IPL and sensorimotor network and between left IPL and frontoparietal network. Within the FM group only, anxiety scores positively correlated with pain-related brain activation in left dorsolateral prefrontal cortex and right IFG/vlPFC, which further highlights the complex interaction between affective (ie, anxiety scores) and sensory (ie, cerebral pain processing) dimensions in this patient group.

Does wearing arthritis gloves help with hand pain and function? A qualitative study into patients’ views and experiences

Objectives

Arthritis gloves are frequently prescribed to people with undifferentiated inflammatory (UIA) or rheumatoid arthritis (RA), to help reduce hand pain and improve function. Nested within a randomised controlled trial testing the effectiveness of arthritis gloves (Isotoner gloves versuss loose-fitting placebo gloves) in people with RA and UIA, this qualitative study aimed to explore participants’ views on the impact of wearing arthritis gloves on their hand pain and function.

Methods

Semi-structured one-to-one interviews were conducted with purposively selected participants following 12-weeks of glove wear. Participants and the interviewer were blinded to the treatment allocation. Interviews were audio-recorded, transcribed verbatim and analysed using thematic analysis.

Results

Participants (intervention n = 10; control n = 9) recruited from 13 NHS hospital sites in the UK participated in the interviews. Two main themes, with sub-themes, were elicited from the data: (1) Mechanisms determining glove use: ‘As soon as your joints get a bit warmer, the pain actually eases’ (thermal qualities; glove-use in daily activities; glove-use during sleep); and (2) Ambivalence about benefits of arthritis gloves: ‘I suppose a normal pair of gloves would do the same sort of thing?’ (are they a help or hindrance?; aesthetic appeal; future use of gloves).

Conclusion

Participants had ambivalent views on the impact of both the intervention and loose-fitting placebo gloves on their hand pain and function, identifying warmth as the main benefit. Ordinary mid-finger length gloves widely accessible from high street suppliers could deliver warmth and provide perceived benefits to hand pain and function.

Clinical Trial Registration

ISRCTN, ISRCTN25892131; Registered 05/09/2016: retrospectively registered.

SZAP exerts analgesic effects on rheumatalgia in CIA rats by suppressing pain hyperalgesia and inhibiting TRPV1 and P2X3

ETHNOPHARMACOLOGICAL RELEVANCE

ShexiangZhuifeng Analgesic Plaster (SZAP) is a traditional Chinese medicine and transdermal formulation composed of many Chinese herbs and active compounds. SZAP was recently approved by the China Food and Drug Administration for the treatment of pain associated with osteoarticular diseases and is preferred by most rheumatoid arthritis patients in China. However, its mechanism has not been elucidated in detail.

AIM OF THE STUDY

We sought to determine the analgesic effect of SZAP in collagen-induced arthritis (CIA) rats and explore the underlying mechanisms of pain transmission, such as via the TRPV1 and P2X3 receptors.

METHODS

After CIA was established, rats were treated with SZAP for 7 days. Paw thickness, arthritis score, and haematoxylin and eosin staining were used to evaluate the effectiveness of SZAP. Paw withdrawal threshold (PWT) and tail-flick latency (TFL) were used to estimate the analgesic effect of SZAP. The levels of PGE₂, BK, 5-HT, SP, and CGRP in the serum and synovium were determined using ELISA kits, and ATP in the synovium was measured using HPLC. The expression of TRPV1 and P2X3 in the DRG was detected using western blotting and immunofluorescence. TRPV1 and P2X3 agonists were further used to determine the analgesic effects of SZAP on CIA rats based on PWT and TFL.

RESULTS

SZAP not only significantly ameliorated arthritis scores and paw thickness by improving the pathological damage of synovial joints, but also remarkably alleviated pain in CIA rats. Further, treatment with SZAP significantly reduced peripheral 5-HT, PGE₂ BK, SP, CGRP, and ATP. Additionally, the expression of TRPV1 and P2X3 in the DRG was markedly downregulated by SZAP. Interestingly, the analgesic effect of SZAP was weakened (reduction of PWT and TFL) when TRPV1 and P2X3 were activated by capsaicin or α,β-meATP, respectively.

CONCLUSION

SZAP ameliorates rheumatalgia by suppressing hyperalgesia and pain transmission through the inhibition of TRPV1 and P2X3 in the DRG of CIA rats.

Icariin-Loaded Hydrogel Regulates Bone Marrow Mesenchymal Stem Cell Chondrogenic Differentiation and Promotes Cartilage Repair in Osteoarthritis

Intra-articular injection of mesenchymal stem cells is a potential therapeutic strategy for cartilage protection and symptom relief for osteoarthritis (OA). However, controlling chondrogenesis of the implanted cells in the articular cavity remains a challenge. In this study, hydrogels containing different concentrations of icariin were prepared by in situ crosslinking of hyaluronic acid and Poloxamer 407. This injectable and thermoresponsive hydrogel, as a 3D cell culture system, showed good biocompatibility with chondrocytes and bone marrow mesenchymal stem cells (BMSCs), as well as promoted proliferation and chondrogenesis of BMSCs through the Wnt/β-catenin signaling pathway. Intra-articular injection of this kind of BMSC-loaded composite hydrogel can significantly prevent cartilage destruction by inducing chondrogenic differentiation of BMSCs, and relieve pain through regulating the expression of inflammatory cytokines (e.g., IL-10 and MMP-13) in the OA model. Incorporating BMSCs into this novel icariin-loaded hydrogel indicates a more superior efficacy than the single BMSC injection, which suggests a great potential for its application in OA.

Neuronal CRMP2 phosphorylation inhibition by the flavonoid, naringenin, contributes to the reversal of spinal sensitization and arthritic pain improvement

BACKGROUND

Rheumatoid arthritis patients usually suffer from arthritic chronic pain. However, due to an incomplete understanding of the mechanisms underlying autoimmune disorders, the management of arthritic pain is unsatisfactory. Here, we investigated the analgesic effect and underlying mechanism of the natural flavonoid naringenin (NAR) in collagen-induced arthritis (CIA) pain.

METHODS

NAR was injected (i.p.) once per day for 42 days after initial immunization, and rats were sacrificed on the 28th (the 21st day after final immunization, PID 21) and 42nd days (PID 35). The inflammatory factors, central sensitization indicators, and CRMP2 phosphorylation, as well as the anti-rheumatoid activity and analgesic effect of NAR, were further investigated.

RESULTS

We found that NAR decreased the arthritis score and paw swelling, as well as the mechanical and thermal pain. The immunofluorescence results also showed a dose dependent effect of NAR on reducing the expressions of spinal cFos, IBA-1, and GFAP on the 28th (PID 21) and 42nd day (PID 35). NAR decreased the phosphorylation of CRMP2 S522 and the expression of the kinase CDK5 in the spinal dorsal horn, but pCRMP2 Y479 was unchanged. In addition, CRMP2 was co-localized with NEUN, but not IBA-1 or GFAP, indicating the involvement of neural CRMP2 phosphorylation in CIA-related pain. Finally, CRMP2 S522 phosphorylation selective inhibitor (S)-lacosamide also alleviated arthritic pain.

CONCLUSIONS

Taken together, our results demonstrate that NAR alleviates inflammation and chronic pain in CIA model, which might be related to its inhibition of neuronal CRMP2 S522 phosphorylation, potentially mitigating the central sensitization. Our study provide evidence for the potential use of NAR as non-opioid-dependent analgesia in arthritic pain.

Generalized pain hypersensitivity and associated factors in gout

OBJECTIVES

Previous studies have indicated that a sizeable proportion of patients with inflammatory arthritis present with features characteristic of central pain sensitization. However, this has not yet been examined in patients with gout. The objective of this study was to explore the presence of generalized pain hypersensitivity and associated factors in patients with diagnosed gout.

METHODS

A cross-sectional survey was performed in outpatients with crystal proven gout using the generalized pain questionnaire (GPQ) to screen for the presence of generalized pain hypersensitivity. Additional self-reported socio-demographic and medical information was collected and several patient-reported outcome measures were completed. Univariable logistic regressions and multivariable LASSO regression analysis with 10-fold cross-validation was used to explore relationships with patient characteristics, clinical features and PROMs.

RESULTS

Of the 97 included patients (84.5% male; mean ± standard deviation age: 68.9 ± 11.9 years), 20 patients (20.6%, 95% CI: 13.0-30.0) reported possible generalized pain hypersensitivity defined as a GPQ score ≥11 (range: 0-28; mean ± standard deviation GPQ: 6.3 ± 5.3). Lower age, concomitant fibromyalgia, and more experienced difficulties in performing their social role were independently associated with generalized pain hypersensitivity. Notably, use of urate lowering therapy was significantly lower in those with generalized pain hypersensitivity.

CONCLUSIONS

Generalized pain hypersensitivity appears to be quite common in gout, despite its more intermittent nature compared with other inflammatory arthritides. As this kind of pain does not respond well to regular treatment, screening for non-inflammatory pain may be important for improving pain management in gout.

The effect of flaxseed with or without anti-inflammatory diet in patients with rheumatoid arthritis, a randomized controlled trial

PURPOSE

Beneficial effect of long-chain ω-3 fatty acids against symptoms of rheumatoid arthritis (RA) has been indicated in previous studies. We examined the effect of flaxseed and anti-inflammatory diet in patients with RA.

METHODS

The 12-week intervention was performed on 120 patients with RA who were randomized to three groups of flaxseed (30 g/day) plus anti-inflammatory diet (AIF group), flaxseed (30 g/day) plus regular diet (RF group), and roasted wheat (30 g/day) plus regular diet (RW group). Disease Activity Score 28-joints (DAS28), health assessment questionnaire (HAQ) disability and pain, quality of life, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor, and anti-cyclic citrullinated peptides (anti-CCP) were measured before and after trial. Analysis was performed using per-protocol and intention-to-treat (ITT) approaches.

RESULTS

One hundred and two patients completed the protocol. Flaxseed decreased DAS28 in RF group compared to RW (- 0.87 ± 1.11 vs. - 0.24 ± 0.78; P = 0.014). Pain severity (P ≤ 0.001), morning stiffness (P < 0.05), and disease feeling (P < 0.01) decreased significantly in AIF and RF groups. HAQ disability and quality of life measurements improved in all 3 groups, with a greater extent in AIF and RF groups (P < 0.001) compared to RW. Between-group differences were significant for DAS28, pain scores, and physical and mental health variables. ESR, CRP, anti-CCP, and rheumatoid factor were not different between groups. Results of ITT analysis did not cause much difference.

CONCLUSIONS

In conclusion, flaxseed may be used as a helpful adjuvant therapy for patients with RA. Calls are open for examining the effect of anti-inflammatory diet on RA symptoms.

TRIAL REGISTRATION NUMBER

Registered at irct.ir as IRCT20190923044858N1, February 6, 2020.

Factors associated with anxiety and depression in rheumatoid arthritis patients: a cross-sectional study

BACKGROUND

The management of anxiety and depression symptoms in rheumatoid arthritis (RA) patients is vital. Previous study findings on this topic are conflicting, and the topic remains to be thoroughly investigated. This study aimed to clarify the association of RA disease activity with anxiety and depression symptoms after controlling for physical disability, pain, and medication.

METHODS

We conducted a cross-sectional study of RA patients from the XXX Rheumatoid Arthritis Management Alliance cohort. We assessed patients using the Disease Activity Score (DAS28), Health Assessment Questionnaire Disability Index (HAQ-DI), and Hospital Anxiety and Depression Scale (HADS). Anxiety and depression symptoms were defined by a HADS score ≥ 8. We analyzed the data using multivariable logistic regression analyses.

RESULTS

Of 517 participants, 17.6% had anxiety symptoms and 27.7% had depression symptoms. The multivariable logistic regression analysis demonstrated that DAS28 was not independently associated with anxiety symptoms (odds ratio [OR] [95% confidence interval; CI] 0.93 [0.48-1.78]; p = 0.82) and depression symptoms (OR [95% CI] 1.45 [0.81-2.61]; p = 0.22). However, DAS28 patient global assessment (PtGA) severity was associated with anxiety symptoms (OR [95% CI] 1.15 [1.02-1.29]; p = 0.03) and depression symptoms (OR [95% CI] 1.21 [1.09-1.35]; p < 0.01). Additionally, HAQ-DI scores ≤ 0.5 were associated with anxiety symptoms (OR [95% CI] 3.51 [1.85-6.64]; p < 0.01) and depression symptoms (OR [95% CI] 2.65 [1.56-4.50]; p < 0.01). Patients using steroids were more likely to have depression than those not using steroids (OR [95% CI] 1.66 [1.03-2.67]; p = 0.04).

CONCLUSIONS

No association was found between RA disease activity and anxiety and depression symptoms in the multivariable logistic regression analysis. Patients with high PtGA scores or HAQ-DI scores ≤ 0.5 were more likely to experience anxiety and depression symptoms, irrespective of disease activity remission status. Rather than focusing solely on controlling disease activity, treatment should focus on improving or preserving physical function and the patient's overall sense of well-being.

Systemic effects of IL-6 blockade in rheumatoid arthritis beyond the joints

Interleukin (IL)-6 is produced locally in response to an inflammatory stimulus, and is able to induce systemic manifestations at distance from the site of inflammation. Its unique signaling mechanism, including classical and trans-signaling pathways, leads to a major expansion in the number of cell types responding to IL-6. This pleiotropic cytokine is a key factor in the pathogenesis of rheumatoid arthritis (RA) and is involved in many extra-articular manifestations that accompany the disease. Thus, IL-6 blockade is associated with various biological effects beyond the joints. In this review, the systemic effects of IL-6 in RA comorbidities and the consequences of its blockade will be discussed, including anemia of chronic disease, cardiovascular risks, bone and muscle functions, and neuro-psychological manifestations.

Kartogenin Promotes the BMSCs Chondrogenic Differentiation in Osteoarthritis by Down-Regulation of miR-145-5p Targeting Smad4 Pathway

BACKGROUND

Transplantation of mesenchymal stem cells (MSCs) is a potential therapeutic strategy for cartilage degeneration of osteoarthritis (OA). But controlling chondrogenic differentiation of the implanted MSCs in the joints remains a challenge. The role of kartogenin (KGN) for chondrogenesis of MSCs has been widely reported, however, the mechanism of chondrogenesis has not been elucidated in OA.

METHODS

In this study, we investigated the miR-145-5p, TGF-β, Samd4, and p-stat3/stat3 expression in cartilage of OA patients and bone marrow mesenchymal stem cells (BMSCs) treated with KGN or miR-145-5p inhibitor. In addition, the cell proliferation and chondrogenic differentiation in vitro and in vivo of BMSCs treated with KGN was also detected.

RESULTS

In OA patients, the expression of miR-145-5p was up-regulated, and the expression of TGF-β, Samd4, and p-stat3/stat3 was inhibited. When the BMSCs treated with miR-145-5p inhibitor, the expression of TGF-β, Samd4, and p-stat3/stat3 was also significantly up-regulated. KGN-treated BMSCs had better proliferation and chondrogenic differentiation by up-regulating the expression of Sox 9, Col-2a1, aggrecan in vitro and in OA by down-regulation of miR-145-5p targeting Smad4 pathway. Moreover, intra-articular injection of KGN-treated BMSCs had a better pain relief effect in OA.

CONCLUSION

The double effect on cartilage protection and pain relief indicates a great potential of intra-articular injection of KGN-treated BMSCs for the treatment of OA.

Intra-Articular Injection of miR-29a-3p of BMSCs Promotes Cartilage Self-Repairing and Alleviates Pain in the Rat Osteoarthritis

BACKGROUND

Stem cells intra-articular injection stagey indicated a potential therapeutic effect on improving the pathological progress of osteoarthritis (OA). However, the long-term effect of stem cells intra-articular injection on the cartilage regeneration remains unclear. miR-29a-3p is predicted to be a critical target for inhibiting insulin-like growth factor-1 expression and may aggravate the progression of OA.

METHODS

In this study, we investigated the therapeutic efficacy of intra-articular injection of bone marrow mesenchymal stem cells (BMSCs) transfected with miR-29a-3p inhibitor in OA.

RESULTS

miR-29a-3p inhibitor transfection did not influence cell viability of BMSCs, while the chondrogenic differentiation potential of BMSCs was significantly improved. Interestingly, intra-articular injection of BMSCs with miR-29a-3p inhibition significantly prevented articular cartilage degeneration by up-regulating the expression of Sox 9, Col-2a1, aggrecan and down-regulating the expression of matrix metalloproteinase, as well as relieved pain in OA.

CONCLUSION

The double effects on cartilage protection and pain relief indicated a great potential of intra-articular injection of miR-29a-3p inhibitor-transfected BMSCs for the treatment of OA.

Chronic Pain in Patients with Rheumatoid Arthritis

PURPOSE OF REVIEW

Chronic pain is highly prevalent in patients with rheumatoid arthritis (RA) and can cause various physical and psychological impairments. Unfortunately, the appropriate diagnosis of chronic pain syndromes in this population can be challenging because pain may be primary to RA-specific inflammation and/or secondary to other conditions, typically osteoarthritis (OA) and fibromyalgia (FM). This disparity further poses a clinical challenge, given that chronic pain can often be discordant or undetected with standard RA-specific surveillance strategies, including serological markers and imaging studies. In this review, we provide a robust exploration of chronic pain in the RA population with emphasis on epidemiology, mechanisms, and management strategies.

RECENT FINDINGS

Chronic pain associated with RA typically occurs in patients with anxiety, female sex, and elevated inflammatory status. Up to 50% of these patients are thought to have chronic pain despite appropriate inflammatory suppression, typically due to peripheral and central sensitization as well as secondary OA and FM. In addition to the standard-of-care management for OA and FM, patients with RA and chronic pain benefit from behavioral and psychological treatment options. Moreover, early and multimodal therapies, including non-pharmacological, pharmacological, interventional, and surgical strategies, exist, albeit with varying efficacy, to help suppress inflammation, provide necessary analgesia, and optimize functional outcomes. Overall, chronic pain in RA is a difficult entity for both patients and providers. Early diagnosis, improved understanding of its mechanisms, and initiation of early, targeted approaches to pain control may help to improve outcomes in this population.

Contribution of P2X4 receptor in pain associated with rheumatoid arthritis: a review

Pain is the most common symptom reported by patients with rheumatoid arthritis (RA) even after the resolution of chronic joint inflammation. It is believed that RA-associated pain is not solely due to inflammation, but could also be attributed to aberrant modifications to the central nervous system. The P2X4 receptor (P2X4R) is an ATP-activated purinergic receptor that plays a significant role in the transmission of information in the nervous system and pain. The involvement of P2X4R during the pathogenesis of chronic inflammatory pain and neuropathic pain is well-established. The attenuation of this receptor alleviates disease pathogenesis and related symptoms, including hyperalgesia and allodynia. Although some studies have revealed the contribution of P2X4R in promoting joint inflammation in RA, how it implicates pain associated with RA at peripheral and central nervous systems is still lacking. In this review, the possible contributions of P2X4R in the nervous system and how it implicates pain transmission and responses were examined.

Inflammation, angiogenesis and sensory nerve sprouting in the synovium of bony ankylosed and not bony ankylosed knees with end-stage haemophilic arthropathy

INTRODUCTION

Clinical practice showed that patients with haemophilia (PwH) with bony ankylosed end-stage haemophilic arthropathy knees reported milder pain than those with not bony ankylosed knees.

AIM

To compare the differences in pain sensation and the histopathological differences in synovial samples of affected knee joints between PwH with bony ankylosed end-stage haemophilic arthropathy knees and those with not bony ankylosed knees.

METHODS

From January 2011 to December 2019, the synovial samples of knee joints were collected during total knee arthroplasty (TKA) surgery for end-stage haemophilic arthropathy. The visual analogue scale (VAS, 0-10) pain score was reviewed from the chart data of the patients. The thickness of the inner layer of the synovium in haematoxylin and eosin (H&E) staining sections was measured. The expression levels of Ki67, IL-1β, TNF-α, CD31, VEGF, NGF and PGP9.5 in the synovium were detected by immunohistochemistry (IHC) method.

RESULTS

Fifty-two end-stage haemophilic arthropathy knee synovial samples from 36 male PwH (34 type A and 2 type B) were collected. Fifteen knees had bony ankylosed (BA-group), and 37 were not bony ankylosed (Not-BA-group). The mean age of patients at TKA surgery of BA-group and Not-BA-group was 32 years (15) and 32 years (10), respectively (p = 0.824). Before TKA surgery, the mean VAS pain scores of patients in the Not-BA-group were significantly higher than those in the BA-group (p < 0.001). The mean thickness of the inner layer of the synovium, the mean rate of Ki67+ cells, the mean density of CD31+ vascular endothelial cells and the expression levels of IL-1β, TNF-α, VEGF and NGF in samples in the Not-BA-group was significantly higher than those in samples in the BA-group (p < 0.001, p = 0.02, p = 0.001, p = 0.117, p < 0.001, p = 0.003 and p = 0.008), respectively. The mean density of PGP9.5+ sensory neural fibres in the Not-BA-group was slightly higher than in the BA-group (p = 0.131). Linear regression analysis showed a significant positive correlation between the VAS pain score and indicators including the synovial thickness, the rate of Ki67+ cells, the expression level of IL-1β, TNF-α, VEGF, NGF and the densities of CD31+ vascular endothelial cells and PGP9.5+ nerve fibres (p < 0.05).

CONCLUSIONS

Worsened hypertrophic synovitis, angiogenesis and sensory nerve sprouting in the synovium may play a critical role in causing worse pain sensation in PwH with not bony ankylosed haemophilic arthropathy knees than in those with bony ankylosed knees.

Increased risk of mental health disorders in patients with RA during the COVID-19 pandemic: a possible surge and solutions

Depression is a common co-morbidity among rheumatoid arthritis (RA) patients, which may translate into difficulty performing activities of daily living. COVID-19 is an unprecedented disaster that has disrupted lives worldwide and led to a rise in the incidence of mental health disorders. Given the widespread economic devastation due to COVID-19, many RA patients, already susceptible to mental illness, maybe at an increased risk of inaccessibility to medical care, accentuated stress, and consequent worsening of existent mental health disorders, or the onset of new mental health disorders such as anxiety, post-traumatic stress disorder, or depression. The objective of this review is to assess if there is an increased risk of mental health disorders in patients with RA during the COVID-19 pandemic. Telemedicine has bridged the transition to remote chronic care in the pandemic period, though certain accessibility and technological challenges are to be addressed. Decreased access to care amid lockdowns and a proposed triggering of disease activity in patients with autoimmune disorders may potentially herald a massive spike in incidence or flares of patients diagnosed with RA in the coming months. Such a deluge of cases may be potentially devastating to an overburdened healthcare system. Rheumatologists may need to prepare for this eventuality and explore techniques to provide adequate care during these challenging times. The authors found that there is a significant association between the adverse impact on the mental health of RA patients and the COVID-19 pandemic. However, more research is needed to highlight individual risk factors.

Patient Reported Outcomes in Chronic Inflammatory Diseases: Current State, Limitations and Perspectives

Chronic inflammatory diseases (CID) are emerging disorders which do not only affect specific organs with respective clinical symptoms but can also affect various aspects of life, such as emotional distress, anxiety, fatigue and quality of life. These facets of chronic disease are often not recognized in the therapy of CID patients. Furthermore, the symptoms and patient-reported outcomes often do not correlate well with the actual inflammatory burden. The discrepancy between patient-reported symptoms and objectively assessed disease activity can indeed be instructive for the treating physician to draw an integrative picture of an individual's disease course. This poses a challenge for the design of novel, more comprehensive disease assessments. In this mini-review, we report on the currently available patient-reported outcomes, the unmet needs in the field of chronic inflammatory diseases and the challenges of addressing these.

Widespread non-joint pain in early rheumatoid arthritis

Objective: The aim of the study was to assess the development of widespread non-joint pain (WNP) in a cohort of patients with early rheumatoid arthritis (RA), the associated health-related quality of life (HRQoL), and clinical and demographic risk factors for WNP.Method: Incident cases with RA, from the Swedish population-based study Epidemiological Investigation of Rheumatoid Arthritis (EIRA), with a follow-up of at least 3 years, constituted the study population. WNP was defined as pain outside the joints in all four body quadrants and was assessed at the 3 year follow-up. Patients who reported WNP were compared to patients without WNP regarding HRQoL, measured by the Short Form-36, at 3 years, and clinical and demographic characteristics at the time of RA diagnosis.Results: A total of 749 patients constituted the study sample, of whom 25 were excluded after reporting already having severe pain before RA diagnosis. At the 3 year follow-up, 8% of the patients reported having WNP as well as statistically significant worse HRQoL. At the time of RA diagnosis, the patients with WNP had worse pain and pain-related features, while no difference was seen in the inflammatory parameters.Conclusion: WNP occurs in a substantial subset of patients with RA, also early in the course of the disease, and the HRQoL for these patients is significantly reduced. Patients who develop WNP at 3 years are already distinguishable at the time of diagnosis by displaying more pronounced pain ratings together with an average level of inflammatory disease activity.

Intra-articular Injection of Chitosan-Based Supramolecular Hydrogel for Osteoarthritis Treatment

BACKGROUND

Pain and cartilage destruction caused by osteoarthritis (OA) is a major challenge in clinical treatment. Traditional intra-articular injection of hyaluronic acid (HA) can relieve the disease, but limited by the difficulty of long-term maintenance of efficacy.

METHODS

In this study, an injectable and self-healing hydrogel was synthesized by in situ crosslinking of N-carboxyethyl chitosan (N-chitosan), adipic acid dihydrazide (ADH), and hyaluronic acid-aldehyde (HA-ALD).

RESULTS

This supramolecular hydrogel sustains good biocompatibility for chondrocytes. Intra-articular injection of this novel hydrogel can significantly alleviate the local inflammation microenvironment in knee joints, through inhibiting the inflammatory cytokines (such as TNF-α, IL-1β, IL-6 and IL-17) in the synovial fluid and cartilage at 2- and even 12-weeks post-injection. Histological and behavioral test indicated that hydrogel injection protected cartilage destruction and relieved pain in OA rats, in comparison to HA injection.

CONCLUSION

This kind of novel hydrogel, which is superior to the traditional HA injection, reveals a great potential for the treatment of OA.

[Pain in rheumatic diseases : What can biologics and JAK inhibitors offer?]

Persistent pain despite adequate inflammation control poses a big challenge in many rheumatic diseases for patients as well as physicians. The focus of drug development over the past years was on anti-inflammatory therapies. Enormous progress has been made and several treatment options have been added. It has been observed that pain triggered by inflammation can be effectively treated by inflammation control; however, the chronic pain component remains a problem, is little studied and specific treatment options are missing. Pain is influenced by inflammatory mediators, such as cytokines, which act on peripheral nociceptors and lead to peripheral sensitization. If inflammation continues, this can potentially lead to central sensitization and chronification of pain via immigration of immune cells and/or local activation of e.g. microglia. This leads to increasing autonomization and uncoupling of pain from the actual inflammatory process. The present review deals with the question if bDMARD or tsDMARD also show benefits concerning pain processes in addition to the profound inhibitory effects on inflammation. There are preclinical data that show an influence on sensitization following the use of cytokine inhibitors. On the other hand, so far clinical data show that bDMARDs as well as tsDMARDs consistently rapidly and reliably reduce nociceptive inflammatory pain across disease entities. An effect especially on the process of central sensitization and therefore on chronification of pain cannot be finally evaluated based on the currently available data.