A pathogenetic model for erosive synovitis: lessons from animal arthritides

Area of Science:

• Immunology
• Rheumatology
• Microbiology

Background:

• Adjuvant arthritis, streptococcal cell wall-induced arthritis, and Erysipelothrix insidiosa arthritis are established laboratory models.
• These models exhibit relapsing, erosive synovitis, a condition affecting synovial joints.

Purpose of the Study:

• To review the experimental literature on the pathogenesis of these arthritides.
• To develop a testable model for the pathogenesis of relapsing, erosive synovitis.

Main Methods:

• Review of experimental literature on adjuvant arthritis, streptococcal cell wall-induced arthritis, and Erysipelothrix insidiosa arthritis.
• Synthesis of findings to propose a unifying pathogenetic model.

Main Results:

• The pathogenesis of these arthritides appears similar across the models.
• Persistence of nonbiodegradable microbial cell wall components, particularly peptidoglycans, within macrophages in the pannus is identified as a central event.

Conclusions:

• A model is proposed where persistent microbial components in macrophages drive erosive synovitis.
• This model is testable and relevant to understanding erosive synovitis in humans.