Non-nociceptive pain in rheumatoid arthritis is frequent and affects disease activity estimation: cross-sectional data from the FRAME study

Joint tenderness at 3 months follow-up better predicts long-term pain than baseline characteristics in early rheumatoid arthritis patients

OBJECTIVE

To investigate pain course over time and to identify baseline and 3-month predictors of unacceptable pain with or without low inflammation in early RA.

METHODS

A cohort of 275 patients with early RA, recruited in 2012-2016, was investigated and followed for 2 years. Pain was assessed using a visual analogue scale (VAS; 0-100 mm). Unacceptable pain was defined as VAS pain >40, and low inflammation as CRP <10 mg/l. Baseline and 3-month predictors of unacceptable pain were evaluated using logistic regression analysis.

RESULTS

After 2 years, 32% of patients reported unacceptable pain. Among those, 81% had low inflammation. Unacceptable pain, and unacceptable pain with low inflammation, at 1 and 2 years was significantly associated with several factors at 3 months, but not at baseline. Three-month predictors of these pain states at 1 and 2 years were higher scores for pain, patient global assessment, and the health assessment questionnaire, and more extensive joint tenderness compared with the number of swollen joints. No significant associations were found for objective inflammatory measures.

CONCLUSION

A substantial proportion of patients had unacceptable pain with low inflammation after 2 years. Three months after diagnosis seems to be a good time-point for assessing the risk of long-term pain. The associations between patient reported outcomes and pain, and the lack of association with objective inflammatory measures, supports the uncoupling between pain and inflammation in RA. Having many tender joints, but more limited synovitis, may be predictive of long-term pain despite low inflammation in early RA.

Examining pain severity in women with rheumatoid arthritis: the impact of pain self-efficacy and perceived partner's emotional support

BACKGROUND

Empirical data suggest that psychosocial factors, such as pain self-efficacy (PSE) and emotional support from a partner, may alleviate the suffering caused by rheumatoid arthritis (RA) pain. However, the data are ambiguous and warrant a more comprehensive investigation into the effect of these factors on the severity of RA pain. The objective of the present study was to assess the significance of PSE and emotional support from a partner in relation to pain severity among women with RA.

PARTICIPANTS AND PROCEDURE

The study included a sample of 196 women diagnosed with RA with the mean age of 41.54. The study employed the following measures: Rheumatoid Arthritis Pain Scale, Pain Self-efficacy Questionnaire, and Communication Based Emotional Support Scale.

RESULTS

The analysis revealed that higher PSE emerged as the strongest predictor for lower pain severity across all components of RA pain. However, the impact of the partner's emotional support on pain severity was not as evident and varied depending on the specific pain component. Furthermore, the use of pain medications significantly predicted three out of four pain components. Mediation analysis revealed that perceived emotional support from a partner directly affected women's RA pain intensity, as well as indirectly through the PSE as a mediator. Moderated mediation analysis demonstrated that the association between PSE and pain severity weakened as the duration of RA increased.

CONCLUSIONS

Enhancing women's PSE and providing appropriate training for their partners to offer effective emotional support may play a crucial role in the treatment of RA.

A systematic review and meta-analysis of questionnaires to screen for pain sensitisation and neuropathic like pain in inflammatory arthritis

BACKGROUND

Targeted pain relief is a major unmet medical need for patients with inflammatory arthritis (IA), where approximately 40% of patients experience persistent pain. Self-reported questionnaires which report on pain sensitivity and neuropathic like pain may provide an insight into certain pain types to guide targeted treatment.

OBJECTIVE

In this systematic review and meta-analysis we evaluated self-reported pain sensitivity and neuropathic like pain in subjects with IA, as defined by questionnaires.

METHODS

MEDLINE, Embase, Web of Science, PsycINFO and google scholar were searched for publications and conference abstracts, reporting on pain sensitivity and neuropathic pain using painDETECT, DN4, LANSS, CSI, PSQ and McGill pain questionnaire in adult patients with IA. Risk of bias was assessed using National Institute of Health Quality Assessment Tool. Meta-analysis according to individual questionnaire criteria, was undertaken.

RESULTS

63 studies (38 full text and 25 conference abstracts) were included in the review, reporting on a total of 13,035 patients. On meta-analysis, prevalence of pain sensitivity/neuropathic like pain in IA was 36% (95% CI 31-41%) according to painDETECT, 31% (95% CI 26-37%) according to the DN4, 40% (95% CI 32-49%) according to the LANSS and 42% (95% CI 34-51%) according to the CSI. On meta-regression, prevalence of pain sensitivity/neuropathic pain in RA was significantly lower than SpA (p = 0.01) and PsA (p = 0.002) using the painDETECT questionnaire. Across all questionnaires, pain sensitivity and neuropathic like pain were significantly associated with worse pain severity, disease activity, disability, quality of life and anxiety and depression measures. Studies reporting on whether neuropathic like pain is a predictor of treatment outcome were inconsistent.

CONCLUSION

Pain sensitivity and neuropathic like pain contribute to pain perception in up to 42% of patients with IA. Despite substantial heterogeneity between studies on meta-analysis, this review highlights the large proportion of patients with IA who may experience pain due to underlying mechanisms other than, or in addition to, synovial inflammation.

Small Synthetic Hyaluronan Disaccharide BIS014 Mitigates Neuropathic Pain in Mice

Neuropathic pain (NP) is a challenging condition to treat, as the need for new drugs to treat NP is an unmet goal. We investigated the analgesic potential of a new sulfated disaccharide compound, named BIS014. Oral administration (p.o.) of this compound induced ameliorative effects in formalin-induced nociception and capsaicin-induced secondary mechanical hypersensitivity in mice, but also after partial sciatic nerve transection (spared nerve injury), chemotherapy (paclitaxel)-induced NP, and diabetic neuropathy induced by streptozotocin. Importantly, BIS014, at doses active on neuropathic hypersensitivity (60 mg/kg/p.o.), did not alter exploratory activity or motor coordination (in the rotarod test), unlike a standard dose of gabapentin (40 mg/kg/p.o.) which although inducing antiallodynic effects on the NP models, it also markedly decreased exploration and motor coordination. In docking and molecular dynamic simulation studies, BIS014 interacted with TRPV₁, a receptor involved in pain transmission where it behaved as a partial agonist. Additionally, similar to capsaicin, BIS014 increased cytosolic Ca²⁺ concentration ([Ca²⁺]_c) in neuroblastoma cells expressing TRPV₁ receptors; these elevations were blocked by ruthenium red. BIS014 did not block capsaicin-elicited [Ca²⁺]_c transients, but inhibited the increase in the firing rate of action potentials in bradykinin-sensitized dorsal root ganglion neurons stimulated with capsaicin. Perspective: We report that the oral administration of a new sulfated disaccharide compound, named BIS014, decreases neuropathic pain from diverse etiology in mice. Unlike the comparator gabapentin, BIS014 does not induce sedation. Thus, BIS014 has the potential to become a new efficacious non-sedative oral medication for the treatment of neuropathic pain.

Using the derived 28-joint disease activity score patient-reported components (DAS28-P) index as a discriminatory measure of response to disease-modifying anti-rheumatic drug therapy in early rheumatoid arthritis

Background

The 28-joint disease activity score (DAS28) is a widely used measure to assess disease activity in rheumatoid arthritis (RA). The DAS28-P index, a derived proportion of the patient-reported components (joint tenderness and patient global assessment) within the DAS28, has been utilized as a discriminatory measure of non-inflammatory pain mechanisms in RA. This study aimed to evaluate the use of the DAS28-P index as a predictor of treatment response in early RA.

Methods

Patients with early RA enrolled in a supplemental fish oil clinical trial received a combination of disease-modifying anti-rheumatic drugs (DMARDs) according to a ‘treat-to-target’ protocol. First, consecutive measures of the DAS28-P index, derived from the DAS28-erythrocyte sedimentation rate (DAS28-ESR), at each visit over a 1-year period were estimated for each patient. Then, distinct subgroups of treatment responders based on the trajectories of the DAS28-P indices were identified using bivariate k-means cluster analysis. Data on baseline predictors as well as longitudinal outcomes of disease impact and DMARD use over a 1-year period and radiographic progression over a 3-year period were collected and analyzed using a random intercept, population-averaged generalized estimating equation model.

Results

121 patients were included (74% female; mean age of 57; median of 16 weeks of active disease) and a 3-cluster model was identified—the ‘Responders’ group (n = 58; 48%), the ‘Partial Responders’ group (n = 32; 26%), and the ‘Non-Responders’ group (n = 31; 26%). The ‘Partial Responders’ group had consistently higher proportions of the DAS28-P index throughout the study period and had minimal radiographic progression over time, with the lowest joint erosion score of 0.9 [95% confidence interval (CI) 0.2, 1.6], observed at the 3-year follow-up. At 52 weeks, the methotrexate dose was higher for both ‘Partial Responders’ and ‘Non-Responders’ groups (18.5 mg [95% CI 15.5, 21.5] and 18.6 mg [95% CI 15.3, 21.8] respectively), when compared with the ‘Responders’ group (12.8 mg [95% CI 14.7, 20.9]).

Conclusions

Persistently high DAS28-P index scores are useful to distinguish poor patient global assessment and excessive treatment escalation in early RA, suggestive of underlying non-inflammatory pain contributing to higher disease activity score. Early identification of patients with discordant subjective and objective components of composite disease activity measures may allow better tailoring of treatment in RA.

Predictors of unacceptable pain with and without low inflammation over 5 years in early rheumatoid arthritis-an inception cohort study

Objectives

Pain is a major symptom in patients with rheumatoid arthritis (RA). In early RA, pain is usually due to synovitis, but can also persist despite effective anti-inflammatory treatment. The objective of this study was to investigate the pain course over time and predictors of unacceptable pain and unacceptable pain with low inflammation, in patients with early RA.

Methods

An inception cohort of 232 patients with early RA, recruited in 1995–2005, was followed in a structured programme for 5 years. Pain was assessed using a visual analogue scale (VAS; 0–100). Unacceptable pain was defined as VAS pain > 40 based on the patient acceptable symptom state (PASS) and low inflammation as CRP < 10 mg/l. Baseline predictors of unacceptable pain were evaluated using logistic regression analysis.

Results

Pain improved significantly during the first 6 months, but then remained basically unchanged. Thirty-four per cent of the patients had unacceptable pain 5 years after inclusion. Baseline predictors of unacceptable pain after 5 years were lower swollen joint counts [odds ratio (OR) 0.71 per standard deviation (95% confidence interval (CI) 0.51–0.99)] and higher VAS for pain and global assessment of disease activity. Unacceptable pain with low inflammation after 5 years was negatively associated with anti-CCP antibodies [OR 0.50 (95% CI 0.22–0.98)].

Conclusion

Over one third of the patients had unacceptable pain 5 years after inclusion. Lower swollen joint count was associated with unacceptable pain at 5 years. The results may be explained by the positive effects of treatment on pain related to inflammation. Non-inflammatory long-lasting pain appears to be a greater problem in anti-CCP-negative patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02550-7.

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.

Why It Hurts: The Mechanisms of Pain in Rheumatoid Arthritis

Pain is a near-universal feature of rheumatoid arthritis, but peripheral joint inflammation may not suffice to explain the etiology of pain in all patients with rheumatoid arthritis. Inflammation in rheumatoid arthritis releases several algogens that may generate pain. Also, central nervous system processes may play a crucial role in the regulation and perpetuation of pain. Several methods for assessing pain in rheumatoid arthritis exist, and recently the role of assessing therapeutics in treating specific etiologies of pain has gained interest.

[Rheumatic diseases and neuropathic pain : Diagnosis and treatment]

Pain is a leading symptom in inflammatory rheumatic diseases. For a long time it has been assumed that this pain is of nociceptive origin; however, in about one fifth of all patients the pain remains despite successful anti-inflammatory treatment and is not typically described as nociceptive by those affected. Recent studies indicate that some patients with rheumatoid arthritis (RA) experience pain with a neuropathic pain component. The treatment of neuropathic pain with damage to the somatosensory system differs markedly from the treatment of nociceptive pain in which the pain processing system is intact. Thus, the recognition and, above all, the more precise differentiation of the pain symptoms of affected patients make a decisive contribution to a successful treatment. With the help of a few points in the history and a physical examination, the assumption of the diagnosis neuropathic pain can often be rejected or substantiated. Pain with a neuropathic component does not adequately respond to typical analgesics. Instead, the high efficacy of co-analgesics, such as anticonvulsants and antidepressants, has been repeatedly proven.

The neuropathic phenotype of the K/BxN transgenic mouse with spontaneous arthritis: pain, nerve sprouting and joint remodeling

The adult K/BxN transgenic mouse develops spontaneous autoimmune arthritis with joint remodeling and profound bone loss. We report that both males and females display a severe sustained tactile allodynia which is reduced by gabapentin but not the potent cyclooxygenase inhibitor ketorolac. In dorsal horn, males and females show increased GFAP⁺ astrocytic cells; however, only males demonstrate an increase in Iba1⁺ microglia. In dorsal root ganglia (DRG), there is an increase in CGRP⁺, TH⁺, and Iba1⁺ (macrophage) labeling, but no increase in ATF3⁺ cells. At the ankle there is increased CGRP⁺, TH⁺, and GAP-43⁺ fiber synovial innervation. Thus, based on the changes in dorsal horn, DRG and peripheral innervation, we suggest that the adult K/BxN transgenic arthritic mice display a neuropathic phenotype, an assertion consistent with the analgesic pharmacology seen in this animal. These results indicate the relevance of this model to our understanding of the nociceptive processing which underlies the chronic pain state that evolves secondary to persistent joint inflammation.

The Use of Oral Analgesics and Pain Self-Efficacy Are Independent Predictors of the Quality of Life of Individuals with Rheumatoid Arthritis

Objectives

This study investigated the relationship between quality of life (QOL) and several factors, including pain assessments, in patients with rheumatoid arthritis (RA).

Methods

This cross-sectional, single-center study enrolled 85 patients with RA. The variables investigated included demographic characteristics, the 28-joint disease activity score with C-reactive protein (DAS28-CRP), painDETECT questionnaire (PDQ), pain self-efficacy questionnaire (PSEQ), and pain catastrophizing scale (PCS). QOL was measured using the Japanese validated version of the European Quality of Life questionnaire with five dimensions and five levels (EQ-5D-5L).

Results

The use of oral steroids and oral analgesics was significantly associated with low EQ-5D-5L scores (P < 0.05). EQ-5D-5L score had a significant positive association with PSEQ (r = 0.414) and significant negative association with age, disease duration, DAS28-CRP, PDQ, and PCS (r = −0.217, −0.343, −0.217, −0.277, and −0.384, respectively). Multiple regression analysis showed that the use of oral analgesics and PSEQ were independent predictors of EQ-5D-5L score (β = -0.248, P < 0.05 and β = 0.233, P < 0.05).

Conclusions

The use of oral analgesics by RA patients may influence their QOL, which, in turn, may affect their feelings of self-efficacy. Various pain management strategies, including surgical treatment, may be explored for the treatment of RA. Furthermore, the PSEQ may be a prominent part of the patient's overall assessment.

Relationship Between Pain and Sedentary Behavior in Rheumatoid Arthritis Patients: A Cross-Sectional Study

OBJECTIVE

Despite the known benefits of physical activity, high numbers of individuals with rheumatoid arthritis (RA) remain physically inactive and sedentary. Little is known about the determinants of sedentary behavior (SB) in RA. This cross-sectional study was undertaken to examine a range of pain characteristics and RA-related symptoms and their relationship with objectively measured SB.

METHODS

In total, 76 adults with RA wore an activPAL4 accelerometer (PAL Technologies) over a 7-day period. Pain characteristics (pain intensity, painful joint count, nonarticular pain), fatigue, sleep, depression, anxiety, and disease activity were assessed. Analyses were first conducted to evaluate correlations with sedentary time. The independent contribution of pain characteristics to variation in SB was analyzed with multivariable linear regression (adjusted for demographic data and disease activity).

RESULTS

Participants with valid accelerometer data (n = 72) spent a mean ± SD of 533.7 ± 100.1 minutes/day in SB. Positive associations with daily SB were found for pain intensity (r = 0.31, P < 0.01) and number of painful joints (r = 0.24, P < 0.05) but not nonarticular pain. In multivariable analyses, pain characteristics were not independently associated with SB. Analyses indicated that disease activity had an indirect association with SB mediated by pain intensity. Other correlates of daily SB included anxiety and depression but not fatigue or sleep.

CONCLUSION

Results suggest that while pain and other RA-related factors do play a role in SB, they do not appear to have a significant influence after accounting for other variables. Future research should investigate SB and the role of factors unrelated to the symptoms of RA.

Association between pain phenotype and disease activity in rheumatoid arthritis patients: a non-interventional, longitudinal cohort study

BACKGROUND

In well-controlled rheumatoid arthritis (RA) without significant joint damage, a substantial proportion of patients complain of persistent pain. Previous studies have identified different pain phenotypes in RA, in which non-nociceptive pain phenotypes are associated with higher concurrent disease activity scores. In this longitudinal study, we explored associations between pain phenotypes and long-term disease activity outcome in RA patients. Secondly, we explored whether pain phenotype is associated with comorbid conditions.

METHODS

One hundred eighty established RA patients were classified with a nociceptive (61%) or a non-nociceptive (39%) pain phenotype, based on their responses to the painDETECT-questionnaire. Two years of clinical follow-up data on disease activity outcomes were collected. Information on comorbid diseases was derived from electronic patient files.

RESULTS

Patients with a non-nociceptive pain phenotype showed higher mean disease activity scores (DAS28, 2.57; 95% CI, 2.37-2.77 vs. 2.11; 95% CI, 1.94-2.27; p < 0.001) and a twofold lower chance of achieving sustained DAS28 remission (OR = 0.49; 95% CI, 0.26-0.92; p = 0.020). Only the tender joint count and patient global health significantly differed between the pain phenotype groups. Patients with a non-nociceptive pain phenotype had more often been diagnosed with concurrent fibromyalgia (9.9% vs. 0.9%; p = 0.007) and other pain-associated comorbid diseases (52.1% vs. 35.8%; p = 0.030) compared with patients with a nociceptive pain phenotype.

CONCLUSION

This longitudinal study showed consistently worse long-term disease activity outcomes in RA patients with a non-nociceptive pain phenotype which appeared to be mainly due to differences in the subjective components of the disease activity score.

TRIAL REGISTRATION

The DREAM cohort study is registered in the Netherlands Trial Register: NTR578.

Neuropathic Pain Component in Axial Spondyloarthritis and the Influence on Disease Burden

OBJECTIVES

Patients with nonradiographic axial spondyloarthritis (nr-axSpA) and radiographic axSpA/ankylosing spondylitis (AS) have similar burden of disease; however, the potential influence of pain characteristics including the neuropathic pain (NeP) component has not been assessed yet. The aim of this study was first to assess frequency of NeP component in patients with axSpA and second to assess the potential influence of NeP on burden of disease.

METHODS

Adult patients who met the Assessment of SpondyloArthritis International Society classification criteria for axSpA were consecutively recruited. Patients were evaluated using the Douleur Neuropathique en 4 Questions interview and painDETECT questionnaire and subgrouped as patients with and without NeP.

RESULTS

Neuropathic pain component was present in 31.4% of patients with axSpA categorized according to Douleur Neuropathique en 4 Questions (31.6% in nr-axSpA vs 31.3% in AS, P = 0.964) and in 33.5% of patients categorized according to painDETECT (35.1% in nr-axSpA vs 32.8% in AS, P = 0.762). Pain characteristics were quite similar between patients with nr-axSpA and AS. Women tented to have more frequent NeP. Patients with NeP component had significantly higher scores in visual analog scale of pain, patient and physician global, fatigue, Bath Ankylosing Spondylitis Disease Activity Index, Ankylosing Spondylitis Disease Activity Score using C-reactive protein, depression, anxiety scores, and physical functions; poorer quality of life (QoL); and similar frequency of fibromyalgia compared with patients without NeP component. In multivariable analysis, having NeP was associated with QoL measures (Ankylosing Spondylitis Quality of Life and Short-Form 36 physical component score) and visual analog scale of fatigue.

CONCLUSIONS

Nearly one third of patients with axSpA may have NeP component regardless of having nr-axSpA or AS. Neuropathic pain component may contribute worsened QoL and poorer patient-reported outcome data and should be kept in mind during patient evaluation.

How do neuropathic pain-like symptoms affect health-related quality of life among patients with rheumatoid arthritis?: A comparison of multiple pain-related parameters

Objectives: Rheumatoid arthritis (RA) pain is thought to be nociceptive. However, recent studies indicate that RA also involves the neuropathic pain (NP) mechanism. We examined pain features and the effect of NP-like symptoms on health-related quality of life (HRQOL) among patients with RA.Methods: The painDETECT questionnaire (PDQ) was used to evaluate NP-like symptoms among 145 outpatients with RA. Disease activity, pain quality, and HRQOL were evaluated. We compared clinical parameters between patients with and without NP-like symptoms and analyzed pain features and the effect of NP-like symptoms on HRQOL, along with multiple other pain-related parameters.Results: Thirty (20.7%) patients had NP-like symptoms (PDQ ≥13). Patient global assessment and evaluator global assessment diverged for patients with RA who had NP-like symptoms. Of the examined pain-related parameters, PDQ score (p = .038, ß = -.173) was associated with the Short-Form 36-Item Health Survey role-social component summary score, but not with the physical or mental component summary scores.Conclusion: NP-like symptoms affected HRQOL among patients with RA. There was discordance between global assessments by patients and by evaluators for patients with RA who had NP-like symptoms. Therefore, NP-like symptoms should be given somewhat more attention when treating patients with RA.

The Effect of Neuropathic Pain Symptoms on Remission in Patients with Early Rheumatoid Arthritis

BACKGROUND

The presence of neuropatic pain (NeP) is common in subjects with established Rheumatoid Arthritis (RA), and it can influence the disease remission. These aspects have not been investigated in patients with Early Rheumatoid Arthritis (ERA).

OBJECTIVE

To investigate the effect of NeP on the achievement of remission in patients with ERA.

METHOD

The study involved consecutive ERA patients with moderate or high disease activity. The painDETECT Questionnaire (PDQ), the 36-item Short Form Health Survey (SF-36), and the Euro- QoL-5 Dimensions (EQ-5D) were administered to all the patients, and their co-morbidity data were used to calculate their modified Rheumatic Disease Comorbidity Index (mRDCI). After six months' follow-up, the presence or otherwise of NeP in each individual patient was calculated, and whether or not the Boolean remission criteria were satisfied.

RESULTS

The study was completed by 115 patients (76% females) whose PDQ scores indicated that 13% had probable NeP. At the end of the follow-up period, 25 patients (21.7%) met the Boolean remission criteria. Logistic regression analysis showed that baseline PDQ scores (p=0.0023) and the mRDCI (p=0.0054) were the strongest predictors of not being in Boolean remission. Only one of the 15 patients with concomitant NeP achieved Boolean remission.

CONCLUSION

The presence of NeP may affect the achievement of remission in ERA patients. The PDQ can be a useful tool to measure central pain sensitisation in such patients.

Efficacy and safety of cannabidiol followed by an open label add-on of tetrahydrocannabinol for the treatment of chronic pain in patients with rheumatoid arthritis or ankylosing spondylitis: protocol for a multicentre, randomised, placebo-controlled study

INTRODUCTION

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are chronic, systemic, inflammatory diseases, primarily in the musculoskeletal system. Pain and fatigue are key symptoms of RA and AS. Treatment presents a clinical challenge for several reasons, including the progressive nature of the diseases and the involvement of multiple pain mechanisms. Moreover, side effects of pain treatment pose an implicit risk. Currently, no well-controlled studies have investigated how medical cannabis affects pain and cognitive functions in RA and AS. The present study aims to evaluate the efficacy and safety of medical cannabis in the treatment of persistent pain in patients with RA and AS with low disease activity.

METHODS AND ANALYSIS

A double-blinded, randomised, placebo-controlled study of cannabidiol (CBD), followed by an open label add-on of tetrahydrocannabinol (THC) with collection of clinical data and biological materials in RA and AS patients treated in routine care. The oral treatment with CBD in the experimental group is compared with placebo in a control group for 12 weeks, followed by an observational 12-week period with an open label add-on of THC in the primary CBD non-responders. Disease characteristics, psychological parameters, demographics, comorbidities, lifestyle factors, blood samples and serious adverse events are collected at baseline, after 12 and 24 weeks of treatment, and at a follow-up visit at 36 weeks. Data will be analysed in accordance with a predefined statistical analysis plan.

ETHICS AND DISSEMINATION

The Danish Ethics Committee (S-20170217), the Danish Medicines Agency (S-2018010018) and the Danish Data Protection Agency approved the protocol. The project is registered in the European Clinical Trials Database (EudraCT 2017-004226-15). All participants will give written informed consent to participate prior to any study-related procedures. The results will be presented at international conferences and published in peer-reviewed journals.

Development and preliminary evaluation of a short self-report measure of generalized pain hypersensitivity

Purpose

Generalized pain hypersensitivity is frequently observed in chronic pain conditions. Currently, identification is based on expert clinical opinion, and in very few cases combined with quantitative sensory testing. The objectives of this study were to develop and evaluate a short self-report measure of generalized pain hypersensitivity: a generalized pain questionnaire (GPQ).

Methods

Items for the GPQ were developed based on a literature review, followed by an interview study with ten rheumatic patients with suspected pain hypersensitivity. We examined the psychometric properties of the preliminary items in a sample of 212 outpatients suffering from either fibromyalgia (FM; n=98) or rheumatoid arthritis (n=114). Additionally, self-reported data were gathered on sociodemographics, fibromyalgia-survey criteria, health status, and neuropathic-like pain features.

Results

Mokken-scale analyses demonstrated a unidimensional seven-item scale with strong homogeneity (H=0.65) and high reliability (r=0.90). Correlations between total GPQ scores and relevant external measures, such as the FM-survey criteria and neuropathic-like pain features, were consistent with a priori expectations, supporting its external construct validity. Furthermore, the GPQ had good accuracy in distinguishing between patients with FM (generally assumed to be the result of central nervous system hypersensitization) and patients with RA (assumed to result mostly in local nociceptive or inflammatory pain), with an area under the receiver-operating characteristic curve of 0.89. A cutoff value >10 had the highest combination of sensitivity (82.7%) and specificity (77.2%).

Conclusion

The GPQ is psychometrically sound and appears promising for measuring the presence and severity of generalized pain hypersensitivity in chronic pain patients.

Concomitant fibromyalgia complicating chronic inflammatory arthritis: a systematic review and meta-analysis

Objectives

This systematic review and meta-analysis will describe the prevalence of concomitant FM in adults with inflammatory arthritis and quantify the impact of FM on DAS.

Methods

Cochrane library, MEDLINE, Psychinfo, PubMed, Scopus and Web of Science were searched using key terms and predefined exclusion criteria. As appropriate, proportional and pairwise meta-analysis methods were used to pool results.

Results

Forty articles were identified. In RA the prevalence of FM ranged from 4.9 to 52.4% (21% pooled). In axSpA the range was 4.11–25.2% (13% pooled in AS only). In PsA the range was 9.6–27.2% (18% pooled). The presence of concomitant FM was related to higher DAS in patients with RA and AS (DAS28 mean difference 1.24, 95% CI: 1.10, 1.37 in RA; BASDAI mean difference 2.22, 95% CI: 1.86, 2.58 in AS). Concomitant FM was also associated with higher DAS in existing PsA studies. Self-reported, rather than objective, components of DAS appear to be raised in the presence of FM (e.g. tender joint count and Visual Analogue Scale (VAS) pain scores).

Conclusion

FM is common in RA, AxSpA and PsA. Comorbid FM appears to amplify DAS and could therefore influence management of these rheumatic conditions.

The course of pain hypersensitivity according to painDETECT in patients with rheumatoid arthritis initiating treatment: results from the prospective FRAME-cohort study

BACKGROUND

Evidence is emerging that pain in rheumatoid arthritis (RA) exists without underlying inflammation. Our objective was to evaluate the prognostic value of pain classification at treatment initiation using the painDETECT questionnaire (PDQ). Outcomes were change in DAS28-CRP and RAMRIS synovitis score.

METHODS

RA patients initiating a disease-modifying anti-rheumatic drug (DMARD) or initiating/ switching a biological agent were included. Follow-up time was 4 months. Clinical examination, imaging (MRI, dynamic contrast-enhanced MRI (DCE-MRI)), and patient-reported outcomes were undertaken. The PDQ was used to differentiate pain mechanisms. Mean change (95% CI) was calculated using ANCOVA. Multivariable regression models were used to determine a prognostic value.

RESULTS

A total of 102 patients were included; 75 were enrolled for MRI. Mean changes in baseline variables were greatest in the high PDQ classification group (> 18), while limited in the intermediate group (13-18). The 12 patients with high baseline PDQ score all changed pain classification group. No prognostic value of PDQ pain classification was found in relation to change of DAS28-CRP, RAMRIS score, or VAS pain. In the unadjusted model, RAMRIS score at baseline was associated with change in DAS28-CRP. The exploratory variables of DCE-MRI did not differ from other inflammatory variables.

CONCLUSIONS

In RA patients a high PDQ score (non-nociceptive pain) at baseline was not associated with worse outcomes, in fact these patients had numerically greater improvement in DAS28-CRP. However, pain classification by PDQ was not independently associated with change in DAS28-CRP, RAMRIS score, or VAS pain in the prognostic models. Furthermore, patients classified with a high baseline PDQ score changed pain classification group. Patients with unclear pain mechanism had reduced numerically treatment response.

TRIAL REGISTRATION

The study was approved by the Regional Ethics Committee of the Capital of Denmark April 18 2013; identification number H-3-2013-049 .

Comparison of Pain Characteristics in Patients with Rheumatoid Arthritis and Systemic Sclerosis with Particular Reference to the Neuropathic Pain Component: Cross-Sectional Study

OBJECTIVE

The aim of the study was to compare characteristics of pain in terms of neuropathic pain (NeP) and to assess the association between the neuropathic component and quality of life (QoL) in patients with systemic sclerosis (SSc) and rheumatoid arthritis (RA).

SUBJECTS AND METHODS

Fifty-four patients (47 females, 7 males) with SSc and 53 patients (46 females, 7 males) with RA were assessed for outcome measures including disease activity, physical functions, mental condition and health-related QoL (HRQoL) measures (Short Form-36; Hospital Anxiety and Depression Scale), and pain. NeP was assessed by the Douleur Neuropathique 4 (DN4) and PainDetect questionnaires in this cross-sectional study.

RESULTS

The patients had similar education, smoking status, functioning, and HRQoL. However, the patients with RA declared a more severe visual analogue scale of pain and a higher BMI than those with SSc. The NeP component was detected in 42.6% (n = 23) of the SSc patients and in 45.3% (n = 24) of the RA patients (p > 0.05) according to DN4. On PainDetect, possible NeP was detected in 13.0% (n = 7) versus 15.1% (n = 8), whereas 16.7% (n = 9) versus 17.0% (n = 9) were likely to have NeP in SSc and RA, respectively (p > 0.05). Most of the NeP characteristics were similar in SSc and RA, except for numbness and painful cold, which were notably more common in patients with SSc. Having the NeP component (according to DN4) had no influence on functioning and HRQoL in SSc; however, the NeP component revealed a heavier burden of disease regarding functional status, HRQoL, and psychometric components in RA.

CONCLUSION

The NeP component was similar between patients with SSc and RA. However, NeP was associated with a heavier burden of disease in patients with RA.

Clinical characteristics of importance to outcome in patients with axial spondyloarthritis: protocol for a prospective descriptive and exploratory cohort study

INTRODUCTION

Spondyloarthritis (SpA) is a heterogeneous spectrum of rheumatic diseases with either predominantly axial inflammatory symptoms of the spine and sacroiliac joints or predominantly peripheral arthritis. The two main entities of axial SpA (axSpA) are ankylosing spondylitis or non-radiographic axSpA (nr-axSpA). Tumour necrosis factor-α inhibitors have revolutionised the treatment of patients with axSpA who failed to respond to non-steroidal anti-inflammatory drugs and physical therapy. Chronic pain is common in patients with SpA and may still persist despite the lack of signs of inflammation. This has led researchers to hypothesise that central pain sensitisation may play a role in the generation of chronic pain in SpA. The painDETECT Questionnaire (PDQ) is a screening tool developed to detect neuropathic pain components. The primary objective is to explore the prognostic value of the PDQ regarding treatment response in patients with axSpA 3 months after initiating a biological agent. Secondary aim is to evaluate the impact of extra-articular manifestations, comorbidities and patient-reported outcomes and elucidate if these factors influence treatment response.

METHOD AND ANALYSIS

We will include 60 participants (≥18 years of age) diagnosed with axSpA independent of main entity, who initiate or switch treatment of a biologic. Data will be collected at baseline and at endpoint following Danish clinical practice (≥3 months) of treatment with biologics. We will explore whether the PDQ and other phenotypical patient characteristics are prognostically important for response to biological therapy according to established response criteria like 50% improvement in the Bath Ankylosing Spondylitis Disease Activity Index (50%) and Ankylosing Spondylitis Disease Activity Score.

ETHICS AND DISSEMINATION

The study is approved by the Region of Southern Denmark's Ethics committee (S-20160094) and has been designed in cooperation with patient representatives. The study is registered at clinicaltrials.gov (NCT02948608, pre-results). Dissemination will occur through publication(s) in international peer-reviewed journal(s).

Patient-reported Outcomes as Predictors of Change in Disease Activity and Disability in Early Rheumatoid Arthritis: Results from the Yorkshire Early Arthritis Register

OBJECTIVE

To assess patient-reported variables as predictors of change in disease activity and disability in early rheumatoid arthritis (RA).

METHODS

Cases were recruited to the Yorkshire Early Arthritis Register (YEAR) between 1997 and 2009 (n = 1415). Predictors of the 28-joint Disease Activity Score (DAS28) and the Health Assessment Questionnaire-Disability Index (HAQ-DI) at baseline and change over 12 months were identified using multilevel models. Baseline predictors were sex, age, symptom duration, autoantibody status, pain and fatigue visual analog scales (VAS), duration of early morning stiffness (EMS), DAS28, and HAQ-DI.

RESULTS

Rates of change were slower in women than men: DAS28 fell by 0.19 and 0.17 units/month, and HAQ-DI by 0.028 and 0.023 units/month in men and women, respectively. Baseline pain and EMS had small effects on rates of change, whereas fatigue VAS was only associated with DAS28 and HAQ-DI at baseline. In patients recruited up to 2002, DAS28 reduced more quickly in those with greater pain at baseline (by 0.01 units/mo of DAS28 per cm pain VAS, p = 0.024); in patients recruited after 2002, the effect for pain was stronger (by 0.01 units/mo, p = 0.087). DAS28 reduction was greater with longer EMS. In both cohorts, fall in HAQ-DI (p = 0.006) was greater in patients with longer EMS duration, but pain and fatigue were not significant predictors of change in HAQ-DI.

CONCLUSION

Patient-reported fatigue, pain, and stiffness at baseline are of limited value for the prediction of RA change in disease activity (DAS28) and activity limitation (HAQ-DI).

Contribution of subjective Disease Activity Score 28 (DAS28) components to the response to treatment of rheumatoid arthritis

We investigated the contributions made by the subjective components of the Disease Activity Score 28 (DAS28) to the treatment response of rheumatoid arthritis (RA). In addition, factors associated with poor response to treatment at 6 months, despite normalization of objective measures, were examined. A total of 426 newly diagnosed RA patients were included. The DAS28-P score (the subjective components of the DAS28 relative to the total components) was calculated as DAS28-P = 0.56 ∗ sqrt(TJC28) + 0.014 ∗ (VAS-GH) /0.56 ∗ sqrt(TJC28) + 0.28 ∗ sqrt(SJC28) + 0.7 ∗ In(erythrocyte sedimentation rate (ESR)) + 0.014 ∗ (VAS-GH). The European League Against Rheumatism (EULAR) response was assessed after 6 months of treatment. Of those who failed to attain good EULAR responses, those for whom the objective measures (the ESR, the C-reactive protein level, and swollen joints) were normalized were defined as having failed treatment because of subjective measures. The median (IQR) DAS28 score at baseline was 4.8 (4.04-5.49) and that after 6 months of treatment 3.21 (2.41-3.95). The DAS28-P score fell significantly from baseline to 6 months in good (0.43 versus 0.28, p < 0.001) and moderate responders (0.44 versus 0.4, p = 0.003), but not in non-responders (0.43 versus 0.45, p = 0.727). Younger age, a lower DAS28 score, and a lower DAS28-P score at baseline were related to a good EULAR response. Subjects who failed to respond because of subjective measures tended to have higher DAS28-P scores at baseline. We found that RA patients with high DAS28-P scores, reflecting subjective measures, were less likely to achieve good EULAR responses 6 months after treatment initiation and tended not to be classified as good responders despite normalization of objective measures.

The Reliability of Disease Activity Score in 28 Joints-C-Reactive Protein Might Be Overestimated in a Subgroup of Rheumatoid Arthritis Patients, When the Score Is Solely Based on Subjective Parameters: A Cross-sectional, Exploratory Study

BACKGROUND

Disease Activity Score in 28 Joints (DAS28) is a scoring system to evaluate disease activity and treatment response in rheumatoid arthritis (RA). A DAS28 score of greater than 3.2 is a well-described limit for treatment intensification; however, the reliability of DAS28 might be overestimated.

OBJECTIVE

The aim of this study was to evaluate the reliability of DAS28 in RA, especially focusing on a subgroup of patients with a DAS28 score of greater than 3.2.

METHODS

Data from RA patients registered in the local part of Danish DANBIO Registry were collected in May 2015. Patients were categorized into 2 groups: First, those with DAS28 >3.2 with at least one swollen joint (SJ) or elevated C-reactive protein (CRP) ("objective group"), and second, patients with a DAS28 >3.2 who had no SJ, and CRP values were within the reference range ("subjective group"). Disease Activity Score in 28 Joints, Clinical Disease Activity Index, and Health Assessment Questionnaire scores were calculated for each group. We defined new score, DAS28 subjective, to focus on subjective parameters.

RESULTS

Two hundred thirty patients were included; 198 (86.1%) and 32 (13.9%) patients were in the objective and subjective groups, respectively. Patients in the subjective group had lower mean values of DAS28 (P < 0.001) and Evaluator Global Assessment (P < 0.001) with less common immunoglobulin M rheumatoid factor (P < 0.001) and anti-cyclic citrullinated peptide positivity (P = 0.02) and contrarily higher mean values of tender joints (P = 0.04) and DAS28 based on subjective parameters (P = 0.003) compared with the objective group.

CONCLUSIONS

Rheumatoid arthritis scoring systems should be used cautiously in patients who are considered for treatment intensification. Patients with central sensitization and psychological problems and those with false-positive diagnosis of RA are at high risk of overtreatment.

Patients with Rheumatoid Arthritis and Chronic Pain Display Enhanced Alpha Power Density at Rest

Patients with chronic pain due to neuropathy or musculoskeletal injury frequently exhibit reduced alpha and increased theta power densities. However, little is known about electrical brain activity and chronic pain in patients with rheumatoid arthritis (RA). For this purpose, we evaluated power densities of spontaneous electroencephalogram (EEG) band frequencies (delta, theta, alpha, and beta) in females with persistent pain due to RA. This was a cross-sectional study of 21 participants with RA and 21 healthy controls (mean age = 47.20; SD = 10.40). EEG was recorded at rest over 5 min with participant's eyes closed. Twenty electrodes were placed over five brain regions (frontal, central, parietal, temporal, and occipital). Significant differences were observed in depression and anxiety with higher scores in RA participants than healthy controls (p = 0.002). Participants with RA exhibited increased average absolute alpha power density in all brain regions when compared to controls [F_(1.39) = 6.39, p = 0.016], as well as increased average relative alpha power density [F_(1.39) = 5.82, p = 0.021] in all regions, except the frontal region, controlling for depression/anxiety. Absolute theta power density also increased in the frontal, central, and parietal regions for participants with RA when compared to controls [F_{(1, 39)} = 4.51, p = 0.040], controlling for depression/anxiety. Differences were not exhibited on beta and delta absolute and relative power densities. The diffuse increased alpha may suggest a possible neurogenic mechanism for chronic pain in individuals with RA.