Direct degradation of articular cartilage by rheumatoid synovial fluid: contribution of proteolytic enzymes

J Rheumatol. 1994 Oct;21(10):1796-801.


Objective: To test the effects of synovial fluids (SF) on human cartilage in an in vitro model.

Methods: Freshly collected SF were incubated with cryostat sections of articular cartilage, and glycosaminoglycan (GAG) loss determined by microdensitometry after alcian blue staining.

Results: Of 20 rheumatoid SF, 11 induced significant GAG loss compared with only 3 out of 15 osteoarthritic SF. The effect of rheumatoid fluids appeared to be related to disease activity. GAG loss was partially prevented by a broad spectrum serine protease inhibitor and a specific elastase inhibitor. Cartilage degrading activity was lost on storage which may explain why it has not been widely reported before.

Conclusion: Rheumatoid SF can directly degrade cartilage through the action of proteases. There is an involvement of serine proteases, elastase in particular.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / metabolism*
  • Arthritis, Rheumatoid / physiopathology*
  • Cartilage, Articular / chemistry
  • Cartilage, Articular / metabolism*
  • Female
  • Glycosaminoglycans / analysis
  • Glycosaminoglycans / metabolism
  • Humans
  • Iodoacetamide / pharmacology
  • Male
  • Middle Aged
  • Osteoarthritis / metabolism
  • Osteoarthritis / physiopathology
  • Pancreatic Elastase / analysis
  • Pancreatic Elastase / physiology
  • Pepstatins / pharmacology
  • Peptide Hydrolases / analysis
  • Peptide Hydrolases / physiology*
  • Synovial Fluid / enzymology
  • Synovial Fluid / physiology*


  • Glycosaminoglycans
  • Pepstatins
  • Peptide Hydrolases
  • Pancreatic Elastase
  • Iodoacetamide