title: 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.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  BACKGROUND
  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.
authors.affiliation: Department of Rheumatology, The Parker Institute, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark.
authors.forename: Anton Wulf
authors.initials: AW
authors.lastname: Christensen
authors.forename: Signe
authors.initials: S
authors.lastname: Rifbjerg-Madsen
authors.forename: Robin
authors.initials: R
authors.lastname: Christensen
authors.forename: Kirstine
authors.initials: K
authors.lastname: Amris
authors.forename: Peter C
authors.initials: PC
authors.lastname: Taylor
authors.forename: Henning
authors.initials: H
authors.lastname: Locht
authors.forename: Karen
authors.initials: K
authors.lastname: Ellegaard
authors.forename: Søren
authors.initials: S
authors.lastname: Torp-Pedersen
authors.forename: Anders
authors.initials: A
authors.lastname: Jespersen
authors.forename: Else Marie
authors.initials: EM
authors.lastname: Bartels
authors.forename: Bente
authors.initials: B
authors.lastname: Danneskiold-Samsøe
authors.forename: Henning
authors.initials: H
authors.lastname: Bliddal
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D059350:Chronic Pain; D003943:Diagnostic Techniques, Neurological; D005260:Female; D006801:Humans; D008297:Male; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D058748:Pain Perception / Q000187:drug effects*; D062072:Patient Acuity; D059227:Postsynaptic Potential Summation / Q000187:drug effects; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D018608:Ultrasonography, Doppler / Q000379:methods
chemical_list: D000893:Anti-Inflammatory Agents
keywords: central nervous system sensitization; inflammation; pain measurement; rheumatoid arthritis; ultrasound doppler