Pain without inflammation in rheumatic diseases

Prescription of non-steroidal anti-inflammatory drugs for patients with inflammatory arthritis decreases with the initiation of tumour necrosis factor inhibitor therapy: results from the ICEBIO registry

OBJECTIVE

To study the impact of tumour necrosis factor-α inhibitor (TNFi) therapy on the use of non-steroidal anti inflammatory drugs (NSAIDs) in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and axial spondyloarthritis (axSpA) in Iceland.

METHOD

This registry cohort study used data from the nationwide database on biologics in Iceland (ICEBIO) and the Icelandic Prescription Medicines Register on disease activity, and filled prescriptions for NSAIDs, to study the period from 2 years before to 2 years after initiation of a first TNFi. Five randomly selected individuals from the general population matched on age, sex, and calendar time for each patient served as comparators.

RESULTS

Data from 940 patients and 4700 comparators were included. Patients with arthritis were prescribed 6.7 times more defined daily doses of NSAIDs than comparators (149 vs 22 per year). After TNFi initiation, NSAID use decreased to a mean of 85 DDD per year, or by 42% in RA, 43% in PsA, and 48% in axSpA. At TNFi initiation, the quintile of axSpA patients who used most NSAIDs reported significantly worse pain (mean ± sd 66 ± 21 vs 60 ± 23 mm), global health (70 ± 20 vs 64 ± 23 mm), and Health Assessment Questionnaire score (1.21 ± 0.66 vs 1.02 ± 0.66) than the other patients, whereas no significant differences were observed in the groups with peripheral arthritis.

CONCLUSION

Patients with inflammatory arthritides requiring TNFi therapy use more NSAIDs than matched comparators, and consumption decreased following TNF initiation. Patient-reported measures are not associated with high NSAID use in patients with peripheral arthritis.

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.

A new perspective on vitamin B12 deficiency in rheumatology: a case-based review

Vitamin B12 (cobalamin) deficiency is common in patients with rheumatic diseases. Pernicious anemia is a well-known cause, but recent reports suggest that autoimmune-derived deficiency may not be limited to this cause alone. Symptoms of low vitamin B12 concentration are often deceptive, mimicking and overlapping with symptoms of other conditions. Neuropsychiatric manifestations, anemia, and fatigue are frequently attributed to a rheumatic disease without further evaluation. In this study, we present three cases of patients with neuropathic pain, depression, fatigue, and muscle weakness, initially attributed to a rheumatic disease, which almost completely resolved after implementing vitamin B12 supplementation. Furthermore, we provide an overview of current scientific reports regarding the potential use of cobalamin in rheumatology. Treatment of pain and neuropathy, often very challenging in long-lasting rheumatic diseases, can be more effective after a course of vitamin B12, even when no apparent deficiency is detected in laboratory tests. Considering recent research demonstrating vitamin B12's nerve-protecting properties, we recommend that physicians should assess vitamin B12 levels early in the diagnostic process of rheumatic diseases. In specific cases, physicians should consider cobalamin supplementation regardless of vitamin B12 serum concentration.

Persistent pain and its predictors after starting anti-tumour necrosis factor therapy in psoriatic arthritis: what is the role of inflammation control?

OBJECTIVE

While considerable focus has been placed on pain due to inflammation in psoriatic arthritis (PsA), less is reported on pain despite inflammation control. Here, we aimed to investigate the occurrence/predictors of persistent pain, including non-inflammatory components, after starting anti-tumour necrosis factor (anti-TNF) therapy.

METHOD

Bionaïve PsA patients starting a first anti-TNF therapy 2004-2010 were identified (South Swedish Arthritis Treatment Group register; N = 351). Outcomes included unacceptable pain [visual analogue scale (VAS) pain > 40 mm], and unacceptable pain despite inflammation control (refractory pain; VAS pain > 40 mm + C-reactive protein < 10 mg/L + ≤ 1 swollen joint of 28), assessed at 0, 3, 6, and 12 months. Baseline predictors were estimated by logistic regression.

RESULTS

Upon starting anti-TNF therapy, 85% of patients reported unacceptable pain, falling to 43% at 3 months and then remaining stable. After 12 months, refractory pain constituted 63% of all unacceptable pain. Higher baseline VAS pain/global, worse physical function and lower health-related quality-of-life were associated with a higher risk of unacceptable/refractory pain at 12 months. More swollen joints and higher evaluator's global assessment were associated with a lower risk of 12-month refractory pain.

CONCLUSIONS

A substantial proportion of PsA patients reported unacceptable pain throughout the first anti-TNF treatment year. At 12 months, refractory pain constituted about two-thirds of this remaining pain load. More objective signs of inflammation at anti-TNF initiation were associated with less future refractory pain. This highlights insufficient effect of biologics in patients with inflammation-independent pain, warranting alternative treatments.

A Cross-Sectional Survey of Physicians' Knowledge and Awareness of Chronic Pain Associated with Rheumatoid Arthritis in Rheumatology Departments in Zhejiang Province, China

Objective

To assess physicians' knowledge and awareness of chronic pain associated with rheumatoid arthritis (RA) in Rheumatology departments throughout Zhejiang province to improve chronic pain relief in RA patients.

Methods

A cross-sectional questionnaire survey was conducted onsite and online among rheumatologists in tertiary and secondary hospitals across Zhejiang province, China. The questionnaire inquired about rheumatoid arthritis-related pain cognition, pain assessment, pain management protocols, and medication choice.

Results

Among the 150 questionnaires included, 98 were from tertiary hospitals, and 52 were from secondary hospitals. There was no difference in rheumatologists' perceptions of chronic pain in RA patients between tertiary and secondary hospitals. About 55.1% of rheumatologists from tertiary hospitals and 44.2% of rheumatologists from secondary hospitals utilized unstandardized pain assessment scales. About 46.9% of rheumatologists in tertiary hospitals and 36.5% of rheumatologists in secondary hospitals favored the numerical rating scale (NRS). About 87.8% of rheumatologists in tertiary hospitals and 71.7% of rheumatologists in secondary hospitals conducted pain assessment within 4 hours of admission. About 66.3% of rheumatologists working in tertiary hospitals and 32.7% of rheumatologists practicing in secondary hospitals believed their hospitals had pain departments. For RA patients who complained of pain for the first time, secondarily, or repeatedly, 48%, 26%, and 36.7% of rheumatologists preferred nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, and opioid analgesics, respectively. For RA patients with mild, moderate, or severe pain, 74%, 6%, and 16% of rheumatologists preferred NSAIDs, glucocorticoids, and opioid analgesics, respectively.

Conclusion

The assessment and treatment of chronic pain associated with RA are not standardized. For management, more rheumatologists preferred NSAIDs and glucocorticoids.

Register-based observational study of associations between inflammatory remission, formal treatment targets and the use of disease-modifying antirheumatic drugs among patients with early rheumatoid arthritis

OBJECTIVE

To assess associations between inflammatory remission, formal treatment targets and the likelihood of starting a new disease-modifying antirheumatic drug (DMARD), among patients with early rheumatoid arthritis (RA).

METHODS

Patients newly diagnosed with RA were identified in the Swedish Rheumatology Quality Register (n=11 784). Disease Activity Score 28 (DAS28) and DMARD-treatment were assessed at RA diagnosis and 3, 6, 12 and 24 months thereafter. Inflammatory remission was defined as: swollen joints (0-28)=0 and C reactive protein <10 mg/L and normal erythrocyte sedimentation rate. The primary treatment target was DAS28 remission (<2.6). The proportion of patients in inflammatory remission who failed to reach DAS28 targets was assessed at each follow-up visit, and their likelihood of starting a new DMARD was compared with patients in inflammatory remission who reached the treatment target. rate ratios (RR) and 95% CIs were estimated with modified Poisson regression.

RESULTS

Overall, 34%, 39%, 44% and 47% were in inflammatory remission at 3, 6, 12 and 24 months. Among these, 20%, 22%, 20% and 19%, respectively, failed to reach DAS28 remission. Patients who failed to reach DAS28 remission despite being in inflammatory remission were more likely to start a new DMARD treatment (RR (95% CI) at 6 months=1.59 (1.29 to 1.96), 12 months=1.52 (1.23 to 1.87)) and 24 months=1.47 (1.20 to 1.80).

CONCLUSION

Failing to reach formal treatment targets, despite being in inflammatory remission, is common among patients with early RA, and is associated with an increased likelihood of starting a new DMARD-treatment.

Cardiovascular issues in rheumatic diseases

Cardiovascular disease is a major cause of morbidity and mortality in rheumatic diseases, particularly rheumatoid arthritis and systemic lupus erythematosus. Timely detection and monitoring of cardiovascular affections by advanced visualization techniques may improve outcomes across most rheumatic diseases. Although high-grade inflammation and (auto)immune pathways are well known for their negative effects on the heart and vasculature, cardiovascular risk estimation remains one of the unresolved critical issues in rheumatic diseases. The issue is complicated further in view of the latest reports on enhanced atherogenesis in the setting of fibromyalgia and osteoarthritis, where inflammation is seemingly not a major pathogenic factor. The intensity of systemic inflammation has been associated with major vascular events in some large cohort studies of inflammatory rheumatic diseases. Experts advocate for tight control of systemic inflammation and modifiable cardiovascular risk factors for reducing the overall risk of vascular events. Increasing patients' and specialists' knowledge and skills in cardiovascular monitoring and prevention is warranted to solve some of the cardiovascular issues in rheumatic diseases. Key Points • Cardiovascular issues are prevalent across all age groups of patients with rheumatic diseases. • Large cohort studies suggest that the intensity of systemic inflammation is a powerful predictor of vascular events in rheumatic diseases. • Reliable and widely tested tools for predicting vascular events in inflammatory rheumatic diseases are currently unavailable. • Empowering patients with rheumatic diseases and first-contact specialists with knowledge and skills to monitor and reduce cardiovascular risk factors' effects is a promising strategy.

Transcranial direct current electrical stimulation in combination with aerobic exercise: A pilot study in post-COVID-19 systemic autoimmune rheumatic patients

BACKGROUND

Systemic autoimmune rheumatic diseases (SARDs) are a group of diseases with multiorgan involvement and a high prevalence of chronic pain and fatigue. Patients with SARDs and post-coronavirus disease 2019 (COVID-19) syndrome experience aggravation of symptoms. In this context, it is essential to establish strategies to reduce chronic pain and fatigue and improve quality of life.

AIM

To assess the efficacy of transcranial direct current stimulation (tDCS) for the treatment of fatigue and pain-associated post-COVID-19 syndrome in patients with SARDs.

METHODS

This study included nine patients with different types of SARDs. All patients had reverse transcription-polymerase chain reaction (RT-PCR) test confirmed COVID-19 as well as significant, persistent fatigue and pain that began to worsen after infection. Anodal tDCS was administered in five daily sessions (2mA, 20 min). Concomitantly, patients were involved in aerobic exercise program. All participants were evaluated using specific questionnaires and strength assessment by handgrip and physical function by timed-up-and-go test and sit-to-stand test at baseline (within one week before tDCS protocol), and one week after tDCS protocol. During all procedures, the patients’ treatments remained unchanged.

RESULTS

The sample comprised eight women and one man with a mean age of 48.7 ± 9.6 years. After the tDCS protocol, pain and fatigue significantly improved on the visual analog scale (P < 0.05). The physical function also improved 9.5 ± 2.7 vs 6.8 ± 0.8 (P = 0.001) for timed-up-go-test and 10.3 ± 3.7 vs 15.1 ± 4.0 (P = 0.037) for sit-to-stand test. None of the patients experienced any adverse events.

CONCLUSION

The present study showed that tDCS in combination with aerobic exercise was effective in improving physical function, and reducing fatigue/pain in SARDs patients with post-COVID-19 syndrome.

Guselkumab provides sustained domain-specific and comprehensive efficacy using composite indices in patients with active psoriatic arthritis

OBJECTIVES

To evaluate the efficacy of guselkumab for the treatment of active PsA utilizing composite indices.

METHODS

Data were pooled from the phase 3 DISCOVER-1 (n = 381) and DISCOVER-2 (n = 739) studies. In both studies, patients were randomized 1:1:1 to subcutaneous guselkumab 100 mg every 4 weeks (Q4W); guselkumab 100 mg at week 0, week 4, then Q8W; or placebo Q4W with crossover to guselkumab 100 mg Q4W at week 24. Composite indices used to assess efficacy through week 52 included Disease Activity Index for Psoriatic Arthritis (DAPSA), Psoriatic Arthritis Disease Activity Score (PASDAS), minimal disease activity (MDA), and very low disease activity (VLDA). Through week 24, treatment failure rules were applied. Through week 52, non-responder imputation was used for missing data.

RESULTS

Greater proportions of guselkumab- than placebo-treated patients achieved DAPSA low disease activity (LDA) and remission, PASDAS LDA and VLDA, MDA, and VLDA at week 24 vs placebo (all unadjusted P < 0.05). At week 52, in the guselkumab Q4W and Q8W groups, respectively, response rates were as follows: DAPSA LDA, 54.2% and 52.5%; DAPSA remission, 18.2% and 17.6%; PASDAS LDA, 45.3% and 41.9%; PASDAS VLDA, 16.9% and 19.5%; MDA, 35.9% and 30.7%; and VLDA, 13.1% and 14.4%. In the placebo-crossover-to-guselkumab group, response rates for all composite indices increased after patients switched to guselkumab, from week 24 through week 52.

CONCLUSION

Treatment with guselkumab provided robust and sustained benefits across multiple PsA domains through 1 year, indicating that guselkumab is an effective therapy for the diverse manifestations of PsA.

TRIAL REGISTRATION

NCT03162796; NCT03158285.

Unmet Needs in Rheumatoid Arthritis: A Subgroup of Patients With High Levels of Pain, Fatigue, and Psychosocial Distress 3 Years After Diagnosis

Objective

The study objective was to identify subgroups of patients with rheumatoid arthritis (RA) based on their health status 3 years after diagnosis and to assess potential associations to clinical presentation at diagnosis.

Methods

This observational study included patients with RA with 3‐year follow‐up data from the Swedish Epidemiological Investigation of RA study, collected from 2011 to 2018. Hierarchical agglomerative cluster analysis, based on symptoms of pain, fatigue, sleep quality, mood disturbances, and overall health‐related quality of life (HRQoL), was used to identify subgroups 3 years after diagnosis. Modified Poisson regression was used to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for the associations between the subgroups and patient characteristics at diagnosis.

Results

A total of 1055 individuals constituted the study population, of whom 1011 had complete data on the clustering variables and were therefore eligible for analysis (73% women, median age 58 years). The following three clusters were identified: cluster 1 (466 patients with good health status), cluster 2 (398 patients in an intermediate group), and cluster 3 (147 patients with high levels of pain and fatigue together with markedly impaired HRQoL). Cluster 3 was associated to higher baseline pain (RR: 3.71 [95% CI: 2.14‐6.41]), global health (RR: 6.60 [95% CI: 3.53‐12.33]), and the Stanford Health Assessment Questionnaire (RR: 4.40 [95% CI: 2.46‐7.87]), compared with cluster 1 (highest compared with lowest quartiles). An inverse association was seen for baseline swollen joint count (RR: 0.51 [95% CI: 0.34‐0.85]).

Conclusion

A subgroup of patients with RA experience high levels of pain, fatigue, and psychosocial distress 3 years after diagnosis. This subgroup already displayed pronounced pain and functional disabilities at diagnosis.

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.

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.

ATP transporters in the joints

Extracellular adenosine triphosphate (ATP) plays a central role in a wide variety of joint diseases. ATP is generated intracellularly, and the concentration of the extracellular ATP pool is determined by the regulation of its transport out of the cell. A variety of ATP transporters have been described, with connexins and pannexins the most commonly cited. Both form intercellular channels, known as gap junctions, that facilitate the transport of various small molecules between cells and mediate cell-cell communication. Connexins and pannexins also form pores, or hemichannels, that are permeable to certain molecules, including ATP. All joint tissues express one or more connexins and pannexins, and their expression is altered in some pathological conditions, such as osteoarthritis (OA) and rheumatoid arthritis (RA), indicating that they may be involved in the onset and progression of these pathologies. The aging of the global population, along with increases in the prevalence of obesity and metabolic dysfunction, is associated with a rising frequency of joint diseases along with the increased costs and burden of related illness. The modulation of connexins and pannexins represents an attractive therapeutic target in joint disease, but their complex regulation, their combination of gap-junction-dependent and -independent functions, and their interplay between gap junction and hemichannel formation are not yet fully elucidated. In this review, we try to shed light on the regulation of these proteins and their roles in ATP transport to the extracellular space in the context of joint disease, and specifically OA and RA.

Increased Levels of Omega-3 Fatty Acids and DHA Are Linked to Pain Reduction in Rheumatoid Arthritis Patients Treated with Janus Kinase Inhibitors

Although Janus kinase inhibitors (JAKi) could reduce patient-reported pain in rheumatoid arthritis (RA), their mechanism remains unclear. Therefore, we examined lipid metabolites change in JAKi-treated patients and evaluate their association with pain reduction. We used ¹H-NMR-based lipid/metabolomics to determine serum levels of lipid metabolites at baseline and week 24 of treatment. Serum levels of significant lipid metabolites were replicated by ELISA in 24 JAKi-treated and 12 tocilizumab-treated patients. Pain was evaluated with patients’ assessment on a 0–100 mm VAS, and disease activity assessed using DAS28. JAKi or tocilizumab therapy significantly reduced disease activity. Acceptable pain (VAS pain ≤20) at week 24 was observed in 66.7% of JAKi-treated patients, and pain decrement was greater than tocilizumab-treated patients (ΔVAS pain 70.0 vs. 52.5, p = 0.0595). Levels of omega-3 fatty acids and docosahexaenoic acid (DHA) were increased in JAKi-treated patients (median 0.55 mmol/L versus 0.71 mmol/L, p = 0.0005; 0.29 mmol/L versus 0.35 mmol/L, p = 0.0004; respectively), which were not observed in tocilizumab-treated patients. ELISA results showed increased DHA levels in JAKi-treated patients with acceptable pain (44.30 µg/mL versus 45.61 µg/mL, p = 0.028). A significant association of pain decrement with DHA change, not with DAS28 change, was seen in JAKi-treated patients. The pain reduction effect of JAKi probably links to increased levels of omega-3 fatty acids and DHA.

Neuropathic Pain and its Relationship With Fibromyalgia, Vitamin D Status and Medication Use in Patients With Ankylosing Spondylitis

Objective

To determine the frequency of neuropathic pain (NeP) and potentially related new factors including fibromyalgia, vitamin D and medication use in ankylosing spondylitis (AS) patients.

Methods

In total, 102 patients with AS were prospectively enrolled in this study and evaluated for pain severity (visual analog scale, VAS), disease activity (the Bath Ankylosing Spondylitis Disease Activity Index, BASDAI), fibromyalgia and current medication use The presence of NeP was also assessed using the painDETECT questionnaire Blood samples were taken from all patients to analyze serum 25-hydroxyvitamin D and inflammatory marker levels.

Results

NeP component 32 (21 [20.6%]; clearly NeP and 11 [10.8%]; mixed NeP) was present in patients with AS Compared to those without NeP, they had significantly higher VAS and BASDAI scores (p=0.022 and 0.003, respectively) In addition, there was a highly significant difference of frequency of fibromyalgia between patients with and without NeP (50.0% vs 5.7%, p<0.001) Vitamin D status and medication use were comparable for patients with and without NeP Logistic regression analysis revealed that only fibromyalgia was a significant predictor of NeP.

Conclusion

This study confirmed that about one-third of AS patients have the NeP component In addition, NeP was found to be associated with the frequency of fibromyalgia However, no relation was found between NeP and vitamin D status and medication use in AS.

Mechanisms and Mediators of Pain in Chronic Inflammatory Arthritis

Purpose of the review

Pain in chronic inflammatory joint diseases is a common symptom reported by patients. Pain becomes of absolute clinical relevance especially when it becomes chronic, i.e., when it persists beyond normal healing times. As an operational definition, pain is defined chronic when it lasts for more than 3 months. This article aims to provide a review of the main mechanisms underlying pain in patients with chronic inflammatory joint diseases, discussing in particular their overlap.

Recent findings

While it may be intuitive how synovial inflammation or enthesitis are responsible for nociceptive pain, in clinical practice, it is common to find patients who continue to complain of symptoms despite optimal control of inflammation. In this kind of patients at the genesis of pain, there may be neuropathic or nociplastic mechanisms.

Summary

In the context of chronic inflammatory joint diseases, multiple mechanisms generally coexist behind chronic pain. It is the rheumatologist’s task to identify the mechanisms of pain that go beyond the nociceptive mechanisms, to adopt appropriate therapeutic strategies, including avoiding overtreatment of patients with immunosuppressive drugs. In this sense, future research will have to be oriented to search for biomarkers of non-inflammatory pain in patients with chronic inflammatory joint diseases.

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.

[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.

Interaction of pain and chronic inflammation

Rheumatic diseases are characterized by chronic inflammation of synovial joints and are often associated with persistent pain and increased pain sensitivity. The inflammatory process is a complex cascade of events involving several mediators, which can lead to a chronic condition of pain. Inflammation can stimulate angiogenesis, and angiogenesis can facilitate inflammation. Inflammatory pain arises from tissue damage via the sensitization of pain receptors (nociceptors). The main peripheral mechanism underlying nociceptive pain is a change in the activity of the nociceptors located in the affected anatomical structures (joints, tendons, and ligaments), which renders them more sensitive to normally painful stimuli (hyperalgesia) or normally non-painful stimuli (allodynia). Neuroimmune interaction has been considered to play an essential role in rheumatic disease. Neurogenic inflammation, which influences normal central nervous system signaling, leads to insufficient signaling/bioavailability of various cytokines. These central mechanisms play an important role in the increased pain sensitivity following inflammation and are responsible for the development of secondary hyperalgesia in regions beyond the injured tissue. Reduction of pain in rheumatic disease requires familiarity with various pain mechanisms.

Physical and Psychosocial Burden of Psoriatic Arthritis: Longitudinal Data From a Population-Based Study in Norway

OBJECTIVE

Psoriatic arthritis (PsA) can have a significant impact on health-related quality of life (HRQoL). Data on the timing of changes in the HRQoL of patients with PsA are limited. The present study was undertaken to explore associations between sleep disturbance, fatigue, pain, anxiety, depression, general health status, and satisfaction with life before and after a diagnosis of PsA compared to the general population.

METHODS

Patients diagnosed with PsA between the Nord-Trøndelag Health Study (HUNT2 [1995-1997] and HUNT3 [2006-2008]) surveys were compared to the general population. The adjusted odds ratio (OR_adj ) with 95% confidence interval (95% CI) was estimated at both time points.

RESULTS

Among 36,507 individuals participating in both the HUNT2 and HUNT3 surveys, 160 were diagnosed with PsA between the surveys. The prevalence of sleep disturbances and fatigue was higher in PsA patients after diagnosis compared to the general population (OR_adj 2.24 [95% CI 1.55-3.25] and OR_adj 1.94 [95% CI 1.27-2.98], respectively). The prevalence of pain and poor health status were higher in patients with PsA compared with the general population even before PsA was diagnosed (OR_adj 2.81 [95% CI 1.96-4.02] and OR_adj 3.08 [95% CI 2.19-4.35], respectively) and increased after diagnosis of PsA (OR_adj 12.87 [95% CI 6.27-26.40] and OR_adj 5.63 [95% CI 3.99-7.95], respectively). For anxiety, depression, and life satisfaction, patients who developed PsA were comparable to the general population both before and after the diagnosis of PsA.

CONCLUSION

Compared to the general population, PsA patients reported a higher prevalence of pain and poorer health status before diagnosis. Increased prevalence of sleep disturbances and fatigue in PsA patients was only found after the PsA diagnosis, and no differences between patients with PsA and the control group were found for anxiety and depression.

Pain and Neuropathic Pain in Rheumatic Diseases

Pain is a challenge to rheumatologists. Not only patients with active arthritis but also patients with a good therapeutic response and even in remission complain of persistent joint pain. It has been proposed that a chronic pain stimulus may have a greater impact in a chronic inflammatory state, and the process towards a pain condition may be influenced by individual predisposition for development of chronic pain. In addition, features of peripheral pain processing may be exacerbated by inflammation, and disturbed pain processing may be a feature contributing to widespread pain. Furthermore, a neuropathic component may be part of the total pain experience of our patients. There are many different strategies of pain therapy in patients with rheumatic diseases, such as pharmacological and non- pharmacological modalities.

Contribution of spathulenol to the anti-nociceptive effects of Psidium guineense

Objectives: Araçá-verdadeiro is the popular name of Psidium guineense (Myrtaceae), whose fruits and leaves are used in Brazilian folk medicine for treatment of inflammation and pain. The focus of the present research was an investigation of the anti-nociceptive, and anti-inflammatory effects of the essential oil from P. guineense (EOPG) leaves, and of spathulenol. The anxiolytic and antidepressive effects associated with chronic pain were also investigated in models of acute or persistent nociception or/and inflammatory pain.Methods and Results: Oral treatment with EOPG (10-100 mg/kg) or spathulenol (10 mg/kg) significantly inhibited formalin-induced nociceptive responses, both sensitivity to cold and edema. Oral treatment with EOPG (10 mg/kg) and spathulenol (10 mg/kg) did not reduce locomotor activity (open field test). Local administration of spathulenol (1000 µg/paw) significantly prevented formalin-induced nociceptive sensitivity to cold and paw edema, and carrageenan-induced mechanical hyperalgesia, paw edema and sensitivity to cold. In the Freund's complete adjuvant (CFA) model, oral treatment with EOPG (10 mg/kg) or spathulenol (10 mg/kg) for 21 days significantly inhibited all analyzed parameters. The percentage maximal inhibition by spathulenol was 76.00% (mechanical hyperalgesia), 71.90% (cold response), 85.00% (edema), 77.16% (myeloperoxidase activity), 97.72% (time in the closed arms in the elevated plus maze), and 49.00% (immobility time in the tail suspension test), in the CFA model. Models employed male Swiss mice, except for the CFA test, which employed C57bL6 male mice (n=6 /group).Conclusion: This study demonstrates that EOPG is an anti-nociceptive and anti-hyperalgesic agent, in acute and continuous treatment, and an anxiolytic and antidepressive agent when tested with the chronic pain experimental state.

BARICITINIB: NEW PHARMACOTHERAPY OPTIONS FOR RHEUMATOID ARTHRITIS AND OTHER IMMUNE-MEDIATED INFLAMMATORY RHEUMATIC DISEASES

Deciphering the mechanisms of the pathogenesis of immune-mediated inflammatory rheumatic diseases (IMIRDs) in conjunction with designing a wide range of biological agents is one of the major medical advances in the 21st century. A new promising area of pharmacotherapy for IMIRDs is associated with the design of the so-called targeted oral medications that primarily include Janus kinase (JAK) inhibitors. The review presents new data on the efficacy and safety of the new JAK inhibitor baricitinib in treating rheumatoid arthritis and other IMIRDs.