title: Does C-reactive protein predict the long-term progression of interstitial lung disease and survival in patients with early systemic sclerosis?
abstract: OBJECTIVE
  There are no identified clinical markers that reliably predict long-term progression of interstitial lung disease (ILD) in systemic sclerosis (SSc; scleroderma). Elevated C-reactive protein (CRP) levels have been reported in SSc patients. We examined the predictive significance of CRP level for long-term ILD progression in a large early SSc cohort.
  
  
  METHODS
  First, the CRP levels were compared between baseline samples of 266 SSc patients enrolled in the Genetics Versus Environment in Scleroderma Outcome Study cohort and 97 unaffected matched controls. Subsequently, the correlation between CRP levels and concomitantly obtained markers of disease severity was assessed. Serially obtained % predicted forced vital capacity (FVC) was used to examine the long-term ILD progression. The predictive significance of CRP level was investigated by a joint analysis of longitudinal measurements (serial FVCs up to 13 years) and survival data. This approach allowed inclusion of all 1,016 FVC measurements and accounted for survival dependency.
  
  
  RESULTS
  We confirmed that baseline CRP levels were higher in SSc patients than controls. CRP levels were associated with absence of anticentromere antibodies and correlated with the concomitant severity of lung, skin, and joint involvement. More importantly, higher baseline CRP levels were associated with shorter survival (P < 0.001) and predicted the long-term decline in FVC independent of potential confounders (age at baseline, sex, ethnicity, disease type, current smoking, body mass index, topoisomerase status, and treatment with immunosuppressive agents) in the multivariable model (P = 0.006).
  
  
  CONCLUSIONS
  Baseline CRP levels are predictive of long-term ILD progression. CRP level might aid clinicians in identifying patients that require more intensive monitoring and treatment.
authors: University of Texas Health Science Center, Houston, TX 77030, USA.
authors: Xiaochun
authors: X
authors: Liu
authors: Maureen D
authors: MD
authors: Mayes
authors: Claudia
authors: C
authors: Pedroza
authors: Hilda T
authors: HT
authors: Draeger
authors: Emilio B
authors: EB
authors: Gonzalez
authors: Brock E
authors: BE
authors: Harper
authors: John D
authors: JD
authors: Reveille
authors: Shervin
authors: S
authors: Assassi
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000097:blood* / Q000209:etiology / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D012595:Scleroderma, Systemic / Q000150:complications* / Q000401:mortality*; D013534:Survival; D014481:United States / Q000453:epidemiology; D014797:Vital Capacity
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein
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