Short summary

Our objective is to determine whether classification from the painDETECT Questionnaire (PDQ), and/or other baseline characteristics (independently or by interaction) are valuable as prognostic factors for treatment response in patients diagnosed with axial spondyloarthropathy (SpA) initiating or switching treatment with a biological agent

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Rationale

The PDQ was developed and validated in 2006, for the purpose of establishing a screening tool to evaluate the likelihood of a neuropathic pain component being present in individual patients. A validated algorithm was developed to be able to calculate a score with a range from 0 to 38. A score of 19 or higher indicates that the presence of a neuropathic pain component is likely, whereas a score of 12 or lower indicates that it is not. A score of 13-18 is considered uncertain. To the best of our knowledge, only one small study has shown PDQ data in relation to SpA. Their results suggest that back pain in AS is a complex pain condition that includes a neuropathic pain component.

We hypothesise that a PDQ score of 19 or higher at baseline is of prognostic importance - potentially enabling prediction of a poorer patient reported treatment response according to the international standards - the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis  Functional Index (BASFI),  Ankylosing Spondylitis Disease Activity Score (ASDAS) when initiating or switching biological treatment in patients with SpA. 

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Description of the cohort

SpA patients initiating or switching anti-rheumatic treatment (biologics) in routine care will be included as one group in this observational study. This study is designed as a "closed cohort" with prospective enrolment of patients with SpA over time. Information about the patients and their exposures will be collected at a single centre at two time points, at baseline and after approximately 3 months of treatment according to the clinical standards in Denmark. Examinations will be carried out consecutively on the same day. Furthermore, there will be an eye examination carried out by an ophthalmologist, within 4 weeks from baseline visit.

Participants will be recruited from The Department of Rheumatology, Odense University Hospital, Svendborg or Odense, Denmark and from The Spine Centre of Southern Denmark, Hospital Lillebaelt, Denmark.

Inclusion criteria:

• Patients diagnosed with SpA according to ASAS
• Between 18 and 80 years of age at time of consent
• Ability and willingness to give written informed consent and to meet the requirements of this protocol
• Patients must have a history of active disease and a BASDAI >40 (10-100) despite current or previous NSAIDs therapy

Exclusion criteria

• Age < 18 years
• No consent
• Pregnancy
• Active or latent TB
• Diagnosed Human immunodeficiency virus
• Diagnosed hepatitis
• Current or past malignant disease
• Recurrent or chronic infection (viral, fungal or bacterial)
• Multiple sclerosis
• Heart failure (NYHA class III/IV)

Data and biological material

Measures to be collected:

• Medical history
• Physical examination
• Biochemistry (peripheral blood)
• HLA-B27 (peripheral blood)
• DANBIO registration
• Informed consent
• Charlson Comorbidity Index
• SF-36
• Simpel Clinical Colitis Activity (SCCAI)
• Harvey Bradshaw´s activity index (HBAI)
• Fecal calprotectin (mg/L) (stool sample)
• Urine electrolytes (urine sample)
• Eye examination

Collaborating researchers and departments

Department of Medicine, Section of Rheumatology, Odense University Hospital, Svendborg

• PhD-student Rikke Asmussen Andreasen, MD
• Inger Marie Jensen Hansen, MD, DMSc, PhD
• Amir Emamifar, MD

Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen

• Lars Erik Kristensen, MD, PhD
• Robin Christensen, MSc, PhD

Department of Rheumatology, Odense University Hospital

• Professor Torkell Ellingsen, MD, PhD
• Hans Christian Horn, MD

Rheumazentrum Ruhrgebiet, Ruhr-University, Herne, Germany

• Xenofon Baraliakos, MD, PhD

Department of Ophthalmology, Odense University Hospital

• Jimmi Wied, MD

Department of Medicine, Section of Gastroenterology, Odense University Hospital, Svendborg

• Claus Aalykke, MD, PhD
• Thomas Ulstrup, MD

Department, Spine Centre of Southern Denmark, Hospital Lillebaelt, Institute of Regional Health Research, University of Southern Dennmark, Middelfart

• Professor Berit Schiøttz-Christensen, MD, PhD