title: Increased serum COMP predicts mortality in SSc: results from a longitudinal study of interstitial lung disease.
abstract: OBJECTIVE
  COMP is a regulator of assembly and maintenance of the fibrillar collagen I and II networks. Serum COMP reflects skin fibrosis in SSc. The purpose of this study was to examine whether serum COMP reflects fibrotic lung involvement in SSc patients and to study if serum COMP predicts mortality.
  
  
  METHODS
  Three overlapping cohorts of 244 SSc patients were studied. Two hundred and eighteen patients were included to study survival, 80 patients to study longitudinal changes of pulmonary function tests and 64 to study pulmonary involvement assessed by high-resolution CT (HRCT). Serum COMP was measured by ELISA. Skin involvement was assessed with the modified Rodnan skin score (mRSS). Data about survival were obtained from the central population registry.
  
  
  RESULTS
  Serum COMP measured within 5 years after the first non-Raynaud's manifestation was a predictor of death, and crude mortality increased by 6% for each COMP unit elevation. Serum COMP levels >15 U/l were associated with a 3.13-fold (95% CI 1.73, 5.64; P < 0.001) increased risk of death. During the first year of follow-up serum COMP and vital capacity (VC) changed inversely (r(s) = -0.32; P = 0.005), but there were no correlations between baseline serum COMP and concurrent findings by spirometry or HRCT.
  
  
  CONCLUSIONS
  Serum COMP early in disease is a predictor of mortality in SSc patients. Serum COMP changes in parallel with lung fibrosis as measured by VC, but the release from fibrotic skin possibly obscures the influx from the lungs and therefore serum COMP seems to have little utility as a marker of lung fibrosis.
authors.affiliation: Department of Rheumatology, Skåne University Hospital, S-221 85 Lund, Sweden. roger.hesselstrand@med.lu.se
authors.forename: Roger
authors.initials: R
authors.lastname: Hesselstrand
authors.forename: Kristofer
authors.initials: K
authors.lastname: Andréasson
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Wuttge
authors.forename: Gracijela
authors.initials: G
authors.lastname: Bozovic
authors.forename: Agneta
authors.initials: A
authors.lastname: Scheja
authors.forename: Tore
authors.initials: T
authors.lastname: Saxne
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood; D064236:Cartilage Oligomeric Matrix Protein; D003430:Cross-Sectional Studies; D016326:Extracellular Matrix Proteins / Q000097:blood*; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008137:Longitudinal Studies; D017563:Lung Diseases, Interstitial / Q000097:blood / Q000150:complications / Q000401:mortality*; D008297:Male; D064235:Matrilin Proteins; D008875:Middle Aged; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000097:blood / Q000150:complications / Q000401:mortality*; D012720:Severity of Illness Index
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; C577553:TSP5 protein, human