Cartilage as a target of autoimmunity: a thin layer

Area of Science:

• Immunology
• Rheumatology
• Biochemistry

Background:

• Articular cartilage provides joint lubrication and load-bearing capacity.
• Cartilage matrix proteins, including collagens and aggrecan, are potential autoantigens.
• Joint-specific immune responses are implicated in autoimmune rheumatic diseases.

Purpose of the Study:

• To review clinical conditions driven by immune-mediated reactions targeting cartilage.
• To explore the role of cartilage as a target organ in autoimmune diseases.
• To highlight the need for further research into cartilage-specific immune responses.

Main Methods:

• Literature review of studies on cartilage autoimmunity.
• Analysis of experimental models of autoimmune rheumatic diseases.
• Discussion of the immunological mechanisms involved in cartilage damage.

Main Results:

• Type II and XI collagen, cartilage oligomeric matrix protein, and aggrecan are identified arthritogenic cartilage proteins.
• Immune responses to cartilage proteins are implicated in rheumatoid arthritis and osteoarthritis.
• Inflammatory processes, autoantibodies, and immune cells contribute to cartilage damage.

Conclusions:

• Immune-mediated reactions to cartilage are central to several autoimmune diseases.
• Osteoarthritis may have inflammatory-driven components.
• Further investigation into the mechanisms of cartilage autoimmunity is warranted.