Temporal summation of pain and ultrasound Doppler activity as predictors of treatment response in patients with rheumatoid arthritis: protocol for the Frederiksberg hospitals Rheumatoid Arthritis, pain assessment and Medical Evaluation (FRAME-cohort) study

INTRODUCTION: Chronic pain is common in rheumatoid arthritis (RA) and may still persist despite regression of objective signs of inflammation. This has led researchers to hypothesise that central pain sensitisation may play a role in the generation of chronic pain in RA. Application of the disease activity score DAS28 can classify some patients with active RA solely based on a high tender joint count and poor patient global health score. In such cases, intensified treatment with anti-inflammatory drugs would be expected to yield poorer results than in cases with DAS28 elevation due to a high score for swollen joints and C reactive protein (CRP). Evaluation of central pain sensitisation in patients with few inflammatory indices may be a predictive tool regarding the effect of anti-inflammatory treatment. Computerised pneumatic cuff pressure algometry (CPA) is a method for assessing temporal summation (ie, degree of central sensitisation). The main objective of this study was to examine the prognostic values of pressure pain-induced temporal summation, ultrasound Doppler activity and the interaction between them in relation to treatment response (DAS28-CRP change) in patients with RA initiating any anti-inflammatory therapy. METHOD AND ANALYSIS: 120 participants ≥18 years of age will be recruited. Furthermore, they must be either (1) diagnosed with RA, untreated with disease-modifying antirheumatic drugs for at least 6 months and about to initiate disease-modifying antirheumatic drug treatment or (2) about to begin or switch treatment with any biological drug for their RA. Data (clinical, imaging, blood samples, patient reported outcomes and CPA measurements) will be collected from each participant at baseline and after 4 months of anti-inflammatory treatment. ETHICS AND DISSEMINATION: This study has been approved by the ethics committee for the Copenhagen region (H-4-2013-007). Dissemination will occur through presentations and publication in international peer-reviewed journals

In psoriatic arthritis fatigue is driven by inflammation, disease duration, and chronic pain: An observational DANBIO registry study

Objective Fatigue is one of the most significant symptoms, and an outcome of great importance, in patients with psoriatic arthritis (PsA), but associations between underlying components of fatigue experienced by patients in relation to the disease have been sparsely investigated. The objectives were to describe the degree of fatigue in PsA patients, and secondly to explore important components associated with fatigue. Methods We performed a cross-sectional survey including patients registered in the Danish nationwide registry DANBIO from December 2013 to June 2014. Principal component analysis was used to identify factors associated with fatigue. Results A total of 1,062 PsA patients were included in the study. A principal component analysis reduced co-variables into three components explaining 63% of fatigue in patients. The first component, contributing to 31% of fatigue, was composed of inflammatory factors including swollen and tender joints, doctors’ global assessment, elevated CRP, and high Pain Detect Questionnaire (PDQ) score; the second component, contributing to 17%, consisted of increasing age and long disease duration. The third component, contributing to 15%, consisted of high PDQ score, tender joint count, increasing age, and concomitant low CRP, suggestive of a chronic pain component consisting of central pain sensitization or structural joint damage. Conclusion Fatigue in PsA patients may be driven by clinical inflammatory factors, disease duration, and chronic pain in the absence of inflammation

In psoriatic arthritis fatigue is driven by inflammation, disease duration, and chronic pain: An observational DANBIO registry study

Objective Fatigue is one of the most significant symptoms, and an outcome of great importance, in patients with psoriatic arthritis (PsA), but associations between underlying components of fatigue experienced by patients in relation to the disease have been sparsely investigated. The objectives were to describe the degree of fatigue in PsA patients, and secondly to explore important components associated with fatigue. Methods We performed a cross-sectional survey including patients registered in the Danish nationwide registry DANBIO from December 2013 to June 2014. Principal component analysis was used to identify factors associated with fatigue. Results A total of 1,062 PsA patients were included in the study. A principal component analysis reduced co-variables into three components explaining 63% of fatigue in patients. The first component, contributing to 31% of fatigue, was composed of inflammatory factors including swollen and tender joints, doctors’ global assessment, elevated CRP, and high Pain Detect Questionnaire (PDQ) score; the second component, contributing to 17%, consisted of increasing age and long disease duration. The third component, contributing to 15%, consisted of high PDQ score, tender joint count, increasing age, and concomitant low CRP, suggestive of a chronic pain component consisting of central pain sensitization or structural joint damage. Conclusion Fatigue in PsA patients may be driven by clinical inflammatory factors, disease duration, and chronic pain in the absence of inflammation.</p

Proportions n (%) of STR groups within PDQ classification-groups.

<p>Proportions n (%) of STR groups within PDQ classification-groups.</p

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

<p><b>Background</b>: The painDETECT questionnaire (PDQ) is a mechanism-based pain classification tool assigning patients to one of three categories depending on the quality of the experienced pain. Patients with non-nociceptive pain score high on the PDQ. The objective was to assess the proportions of the three PDQ classification groups in patients with rheumatoid arthritis (RA) and to explore differences in clinical characteristics.</p> <p><b>Method</b>: RA patients initiating or escalating their RA therapy were included prospectively and underwent a thorough examination programme. Low (PDQ score < 13), medium (PDQ score 13–18), and high (PDQ score > 18) scores indicate nociceptive, unclear/possible neuropathic, or neuropathic pain mechanisms, respectively.</p> <p><b>Results</b>: The 102 included patients were classified into the following PDQ classification groups: low = 65%, medium = 23%, and high = 12%. Patients in the medium and high PDQ groups scored worse on indicators of anxiety, depression, disability, mental health-related quality of life, pain, and fatigue. They also had more tender points and an RA disease activity score based on 28 joints (DAS28) where a higher fraction of the composite score pertained to non-inflammatory factors compared to patients in the low PDQ classification group. There were no differences in objective inflammatory indices across groups. Multiple regression analysis demonstrated that the tender joint count (TJC) and the 36-item Short Form Health Survey (SF36) mental component summary (MCS) score were independently associated with the PDQ score.</p> <p><b>Conclusions</b>: In patients initiating or intensifying medical treatment for their RA, non-nociceptive pain (PDQ score ≥ 13) is common. In these patients, the pain mechanisms result in increased disease activity scores on a non-inflammatory basis.</p

Distribution of painDETECT classification-groups (<13/ 13-18/ >18).

<p>* p < 0.001.</p

Logistic regression analysis for modeling high pain status (≥ median VAS pain of 39 mm).

<p>Logistic regression analysis for modeling high pain status (≥ median VAS pain of 39 mm).</p