title: HLA-B27 and gender independently determine the likelihood of a positive MRI of the sacroiliac joints in patients with early inflammatory back pain: a 2-year MRI follow-up study.
abstract: OBJECTIVE
  To describe how inflammation on MRI of the sacroiliac joints in patients with recent-onset inflammatory back pain (IBP) evolves over time, and to study determinants of activity on MRI of the sacroiliac joint.
  
  
  METHODS
  A 2-year follow-up study with annual MRI of the sacroiliac joints was conducted in patients with IBP of less than 2 years' duration. Images were scored for bone marrow oedema on short τ inversion recovery and enhancement after administration of gadolinium on T1.
  
  
  RESULTS
  Of the 68 patients (38% male; mean age 34.9 ± 10.3 years) enrolled, 44 had a negative baseline MRI. Of these 44 patients, 39 patients had at least one follow-up MRI of whom six patients (15%) developed activity on MRI during follow-up. 24 patients (35%) had an abnormal MRI at baseline. In 23 of these 24 patients follow-up MRI was available. The MRI became negative in seven of these 23 patients (30%) during follow-up. Human leucocyte antigen B27 (HLA-B27) positivity and male gender determined independently the likelihood of a positive MRI at any time point. In an HLA-B27-positive patient the likelihood of a positive MRI during follow-up is 88% if the baseline MRI is positive and 27% if the baseline MRI is negative. In an HLA-B27-negative patient with a negative MRI at baseline the likelihood of a positive MRI during follow-up is less than 5%.
  
  
  CONCLUSIONS
  A positive MRI at baseline predicts a positive MRI during follow-up in HLA-B27-positive patients. A negative MRI at baseline in HLA-B27-negative patients strongly predicts a negative MRI during follow-up.
authors.affiliation: Department of Medicine, Division of Rheumatology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands. m.van.onna@mumc.nl
authors.forename: M
authors.initials: M
authors.lastname: van Onna
authors.forename: A G
authors.initials: AG
authors.lastname: Jurik
authors.forename: D
authors.initials: D
authors.lastname: van der Heijde
authors.forename: A
authors.initials: A
authors.lastname: van Tubergen
authors.forename: L
authors.initials: L
authors.lastname: Heuft-Dorenbosch
authors.forename: R
authors.initials: R
authors.lastname: Landewé
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D015796:HLA-B27 Antigen / Q000032:analysis*; D006801:Humans; D017116:Low Back Pain / Q000209:etiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D012446:Sacroiliac Joint / Q000473:pathology*; D058566:Sacroiliitis / Q000150:complications / Q000175:diagnosis*; D012737:Sex Factors; D025241:Spondylarthritis / Q000150:complications / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D015796:HLA-B27 Antigen