title: The presence of peripheral arthritis delays spinal radiographic progression in ankylosing spondylitis: Observation Study of the Korean Spondyloarthropathy Registry.
abstract: OBJECTIVE
  The aim of this study was to determine whether the presence of peripheral arthritis can affect radiographic structural damage in patients with AS.
  
  
  METHODS
  A total of 915 subjects comprising 363 patients with a history of peripheral arthritis and 552 patients without a history of peripheral arthritis obtained from the Observation Study of the Korean SpA Registry (OSKAR) were analysed looking at the relationship of peripheral arthritis history in a cross-sectional survey as well as the radiographic damage score according to the presence or absence of peripheral arthritis. Radiographs and clinical information were available for 501 subjects (205 peripheral arthritis patients and 296 without peripheral arthritis) at a mean follow-up of 2.7 years. The modified Stoke AS Spinal Score (mSASSS) was examined by two experienced radiologists to validate the results. Reliability was evaluated using the intraclass correlation coefficient for each radiograph.
  
  
  RESULTS
  The agreement between the two readers regarding the mSASSS was good. On simple comparison there was a significant difference in the mSASSS between patients with a history of peripheral arthritis and those without [mean 14.62 (s.e.m. 0.83) vs 18.78 (0.79), P < 0.001]. The mSASSS change was stratified according to the presence or absence of peripheral arthritis at baseline. After adjusting for multiple comparisons by Bonferroni correction, the patients with peripheral arthritis had less mSASSS change than those without peripheral arthritis [3.08 (s.e.m. 0.61) vs 5.18 (0.47), P = 0.008].
  
  
  CONCLUSIONS
  The presence of peripheral arthritis delays spinal radiographic progression in AS.
authors.affiliation: Department of Rheumatology, Research Institute of Medical Sciences, Chonnam National University Medical School and Hospital, Gwangju, Department of Radiology and Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea.
authors.forename: Tae-Jong
authors.initials: TJ
authors.lastname: Kim
authors.affiliation: Department of Rheumatology, Research Institute of Medical Sciences, Chonnam National University Medical School and Hospital, Gwangju, Department of Radiology and Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea.
authors.forename: Seunghun
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Rheumatology, Research Institute of Medical Sciences, Chonnam National University Medical School and Hospital, Gwangju, Department of Radiology and Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea.
authors.forename: Kyung Bin
authors.initials: KB
authors.lastname: Joo
authors.affiliation: Department of Rheumatology, Research Institute of Medical Sciences, Chonnam National University Medical School and Hospital, Gwangju, Department of Radiology and Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea.
authors.forename: Dong-Jin
authors.initials: DJ
authors.lastname: Park
authors.affiliation: Department of Rheumatology, Research Institute of Medical Sciences, Chonnam National University Medical School and Hospital, Gwangju, Department of Radiology and Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea.
authors.forename: Yong-Wook
authors.initials: YW
authors.lastname: Park
authors.affiliation: Department of Rheumatology, Research Institute of Medical Sciences, Chonnam National University Medical School and Hospital, Gwangju, Department of Radiology and Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea.
authors.forename: Shin-Seok
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Rheumatology, Research Institute of Medical Sciences, Chonnam National University Medical School and Hospital, Gwangju, Department of Radiology and Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea. thkim@hanyang.ac.kr.
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kim
mesh_terms: D000328:Adult; D001168:Arthritis / Q000000981:diagnostic imaging*; D044466:Asian People; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D015203:Reproducibility of Results; D056910:Republic of Korea; D013131:Spine / Q000000981:diagnostic imaging*; D013167:Spondylitis, Ankylosing / Q000000981:diagnostic imaging*
keywords: ankylosing spondylitis; modified stoke AS spinal score; peripheral arthritis