title: Predictive factors of radiographic progression in ankylosing spondylitis.
abstract: OBJECTIVE
  The course of ankylosing spondylitis (AS) is rather variable, and the factors that predict radiographic progression remain largely obscure. In this study, we tried to determine the clinical factors and laboratory measures that are useful in predicting the radiographic progression of patients with AS.
  
  
  METHODS
  In 64 consecutive patients with AS, we collected radiographic and laboratory data over 3 years. Radiographic data included images of the sacroiliac (SI) and hip joints and laboratory data included areas under the curve (AUC) of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), alkaline phosphatase (ALP), and hemoglobin (Hb). We investigated associations among changes in radiographic scores, initial clinical manifestations and laboratory measurements.
  
  
  RESULTS
  Changes in scores for the SI joint and lumbar spine did not correlate with AUC for ESR, CRP, or ALP. AUC for Hb did not significantly correlate with radiographic progression in any joint. Patients with hip arthritis at the initial visit showed significantly higher radiographic score changes after 3 years in the SI and hip joint compared to those without hip arthritis. Patients who had shoulder arthritis as the initial manifestation had significantly increased AUCs for ESR and CRP compared to those without shoulder arthritis. However, at 3 years, the change of the lumbar spine score was significantly higher in patients without shoulder arthritis.
  
  
  CONCLUSIONS
  These results indicate that hip arthritis at presentation is a useful clinical marker for predicting the structural damage to the SI and hip joint, and suggest that initial shoulder arthritis correlates with slower radiographic progression of the lumbar spine.
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyungjin
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jaejoon
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joong Kyong
authors.initials: JK
authors.lastname: Ahn
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Hwang
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Park
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyemin
authors.initials: H
authors.lastname: Jeong
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hoon-Suk
authors.initials: HS
authors.lastname: Cha
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eun-Mi
authors.initials: EM
authors.lastname: Koh
mesh_terms: D000293:Adolescent; D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D015207:Osteoarthritis, Hip / Q000097:blood / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D013167:Spondylitis, Ankylosing / Q000097:blood / Q000000981:diagnostic imaging*; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D002097:C-Reactive Protein; D000469:Alkaline Phosphatase
keywords: Acute-phase proteins; Disease progression; Inflammation; Spondylitis, ankylosing