Human cartilage gp-39+,CD16+ monocytes in peripheral blood and synovium: correlation with joint destruction in rheumatoid arthritis

Arthritis Rheum. 2000 Jun;43(6):1233-43. doi: 10.1002/1529-0131(200006)43:6<1233::AID-ANR6>3.0.CO;2-9.


Objective: To investigate the expression of human cartilage (HC) gp-39, a possible autoantigen in rheumatoid arthritis (RA), in peripheral blood and synovium, to characterize its cellular source, and to analyze correlations with clinical features.

Methods: The expression of HC gp-39 in synovium and peripheral blood mononuclear cells (PBMC) was assessed by immunohistochemistry and flow cytometry. Synthesis and secretion were investigated by both reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay.

Results: PBMC expressing HC gp-39 were increased in RA patients compared with spondylarthropathy patients (P = 0.0029) and with healthy control subjects (P = 0.0013). HC gp-39+ cells were also slightly overrepresented in RA synovium (P = 0.01). In both blood and synovium, HC gp-39+ cells were identified as CD14dim,CD16+ monocytes, a phenotype which can differentiate from classic CD14++ monocytes by maturation in vitro. HC gp-39 messenger RNA was detected in RA synovium and PBMC, and PBMC secreted HC gp-39 in vitro. The number of HC gp-39+ PBMC correlated with serum levels of C-reactive protein (r = 0.39, P = 0.003) and HC gp-39 (r = 0.52, P = 0.014). HC gp-39 expression in RA synovial lining correlated with joint destruction (r = 0.77, P < 0.001).

Conclusion: CD16+ monocytes, a cellular source of HC gp-39 in vivo, are overrepresented in both RA peripheral blood and synovial tissue. The presence of HC gp-39+ cells in RA synovium is correlated with the degree of joint destruction. These data support a role of these cells in the local autoimmune response that leads to chronic inflammation and joint destruction.

MeSH terms

  • Adipokines
  • Adult
  • Aged
  • Antigens, CD / blood
  • Antigens, CD / metabolism*
  • Arthritis, Rheumatoid / metabolism*
  • Arthritis, Rheumatoid / pathology
  • Cartilage, Articular / metabolism*
  • Cartilage, Articular / pathology
  • Cell Differentiation
  • Cells, Cultured
  • Chitinase-3-Like Protein 1
  • Female
  • Glycoproteins / blood
  • Glycoproteins / metabolism*
  • Humans
  • Lectins
  • Male
  • Middle Aged
  • Monocytes / metabolism*
  • Monocytes / physiology
  • Phenotype
  • Synovial Membrane / metabolism*
  • Synovial Membrane / pathology


  • Adipokines
  • Antigens, CD
  • CHI3L1 protein, human
  • Chitinase-3-Like Protein 1
  • Glycoproteins
  • Lectins