Serum cartilage oligomeric matrix protein reflects osteoarthritis presence and severity: the Johnston County Osteoarthritis Project

Arthritis Rheum. 1999 Nov;42(11):2356-64. doi: 10.1002/1529-0131(199911)42:11<2356::AID-ANR14>3.0.CO;2-R.


Objective: To characterize serum cartilage oligomeric matrix protein (COMP) levels by age and gender for a radiographically defined population free of hip and knee osteoarthritis (OA), and to examine the potential utility of COMP as a diagnostic biomarker for knee OA.

Methods: Serum samples and knee and hip radiographs were obtained at a baseline evaluation as part of the Johnston County Osteoarthritis Project, a population-based study of OA in rural North Carolina. A total of 291 Caucasian participants were randomly selected for COMP analysis, 143 patients with radiographic knee OA (Kellgren/Lawrence [K/L] grade > or = 2) and 148 controls with neither hip nor knee OA (K/L grade 0), evenly distributed by age and gender. COMP was quantified by competitive enzyme-linked immunosorbent assay with monoclonal antibody 17-C10. The natural log-transformed COMP data were analyzed using general linear models.

Results: Serum COMP levels were significantly elevated (P = 0.0001) in the age > or = 65 group (mean +/- SD 1,302.1 +/- 496.7 ng/ml) versus the age 45-54 and age 55-64 groups (1,058.1 +/- 432.4 and 1,038.6 +/- 313.3, respectively). Serum COMP levels of the OA group were significantly higher than those of the control group (1,208.57 +/- 487.47 ng/ml versus 1,061.83 +/- 370.58 ng/ml; P = 0.0093). Serum COMP levels also increased significantly with knee OA K/L grade (P = 0.0047), knee OA laterality (P = 0.0043), and number of knee and hip joints involved (P = 0.0001). There was no significant difference in serum COMP levels by gender or obesity.

Conclusion: We demonstrate that in a population-based sample, serum COMP levels can distinguish an OA-affected subgroup from an unaffected subgroup and can reflect disease severity and multiple joint involvement in OA.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • Cartilage Oligomeric Matrix Protein
  • Disease Progression
  • Extracellular Matrix Proteins / blood*
  • Female
  • Glycoproteins / blood*
  • Hip Joint / diagnostic imaging
  • Humans
  • Knee Joint / diagnostic imaging
  • Male
  • Matrilin Proteins
  • Middle Aged
  • Osteoarthritis, Knee / blood*
  • Osteoarthritis, Knee / diagnostic imaging
  • Radiography


  • Biomarkers
  • Cartilage Oligomeric Matrix Protein
  • Extracellular Matrix Proteins
  • Glycoproteins
  • Matrilin Proteins
  • TSP5 protein, human