title: The degree of spinal inflammation is similar in patients with axial spondyloarthritis who report high or low levels of disease activity: a cohort study.
abstract: BACKGROUND
  The threshold for disease activity required to start antitumour necrosis factor (TNF) therapy has been arbitrarily set in patients with axial spondyloarthritis (axSpA) at Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥ 4. How this relates to spinal inflammation is unknown.
  
  
  OBJECTIVE
  To systematically compare the clinical, laboratory and imaging data of patients with axSpA with respect to their BASDAI level.
  
  
  METHODS
  A total of 100 consecutive patients with axSpA who had never been treated with TNF blockers were included. Laboratory parameters, spinal MRI and x-rays were quantified. Data were stratified according to BASDAI ≥ 4.
  
  
  RESULTS
  44 patients were diagnosed as non-radiographic axSpA (nraxSpA) and 56 patients as ankylosing spondylitis (AS): median age 40.3 ± 10.4 years; 57% male, mean disease duration since diagnosis 6.4 ± 8.4 years, 88% HLA-B27+, mean modified Stokes Ankylosing Spondylitis Spinal Score 8.3 ± 16.4. 60% of patients had spinal inflammation by MRI. The stratification based on BASDAI ≥ 4 disclosed significant differences in most clinical parameters but not for inflammation: patients with nraxSpA and BASDAI < 4 versus ≥ 4 had 0.9 ± 1.4 and 0.5 ± 0.6 inflammatory lesions/patient, respectively (p=0.6), while patients with AS had 3.6 ± 3.7 and 2.7 ± 3.0 inflammatory lesions/patient, respectively (p=0.4).
  
  
  CONCLUSIONS
  The burden of inflammation is quite comparable in patients with axSpA-regardless of disease activity. These data clearly challenge the concept of the recommended cut-off point of BASDAI ≥ 4.
authors.affiliation: Department of Rheumatology, Rheumazentrum Ruhrgebiet, St Josefs-Krankenhaus, Landgrafenstr, 15 44652 Herne, Germany. kiltz@rheumazentrum-ruhrgbiet.de
authors.forename: U
authors.initials: U
authors.lastname: Kiltz
authors.forename: X
authors.initials: X
authors.lastname: Baraliakos
authors.forename: P
authors.initials: P
authors.lastname: Karakostas
authors.forename: M
authors.initials: M
authors.lastname: Igelmann
authors.forename: L
authors.initials: L
authors.lastname: Kalthoff
authors.forename: C
authors.initials: C
authors.lastname: Klink
authors.forename: D
authors.initials: D
authors.lastname: Krause
authors.forename: E
authors.initials: E
authors.lastname: Schmitz-Bortz
authors.forename: M
authors.initials: M
authors.lastname: Flörecke
authors.forename: M
authors.initials: M
authors.lastname: Bollow
authors.forename: J
authors.initials: J
authors.lastname: Braun
mesh_terms: D000328:Adult; D001416:Back Pain / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D015331:Cohort Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D017063:Outcome Assessment, Health Care; D010147:Pain Measurement; D017060:Patient Satisfaction; D011859:Radiography; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D012720:Severity of Illness Index; D013131:Spine / Q000473:pathology* / Q000503:physiopathology; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology