Comparative Proteomic Analysis of Osteoarthritis and Rheumatoid Arthritis: Identifying Potential Biomarkers

Area of Science:

• Biochemistry
• Proteomics
• Rheumatology

Background:

• Osteoarthritis (OA) and Rheumatoid Arthritis (RA) are distinct joint diseases with overlapping symptoms.
• Accurate differentiation is crucial for effective treatment strategies.
• Identifying unique molecular signatures can aid in diagnosis and therapeutic development.

Purpose of the Study:

• To investigate proteomic differences in synovial fluid between knee OA and RA patients.
• To identify protein biomarkers for OA diagnosis and monitoring disease progression.
• To explore potential therapeutic targets based on differential protein expression.

Main Methods:

• SWATH mass spectrometry was employed to analyze synovial fluid proteomes from OA patients (Kellgren-Lawrence grades 2-4) and RA patients.
• Enzyme-Linked Immunosorbent Assay (ELISA) was used for validation of key proteins.
• Receiver Operating Characteristic (ROC) curve analysis assessed diagnostic potential.

Main Results:

• 45 out of 333 quantified proteins were differentially expressed between OA and RA.
• Aggrecan, versican, and cartilage oligomeric matrix protein (COMP) were significantly altered in OA compared to RA.
• COMP demonstrated strong diagnostic potential, differentiating OA grades from RA with high AUC values (up to 96%).
• Gender-specific differences were observed, with higher COMP levels in males and lower levels in female OA patients compared to RA.

Conclusions:

• Proteomic analysis reveals distinct signatures differentiating knee OA from RA.
• COMP shows significant promise as a diagnostic biomarker for OA, with potential to assess disease severity.
• Further research with larger, sex-balanced cohorts is warranted to validate findings and explore therapeutic implications.