Key Summary of CTXII (Cross-Linked C-telopeptide of Type II Collagen):

Molecular Structure

• Breakdown product of type II collagen in cartilage
• Formed by enzyme-mediated cleavage from matrix metalloproteinases
• Unique structural configuration enables specific tracking of cartilage metabolism

Biological Significance

• Biomarker for cartilage wear and tear
• Metabolized through body fluids and excreted via urine
• Levels influenced by age, gender, hormones, and physical activity

Analytical Methods

• Measured using ELISA technique
• Preferably tested using second morning urine samples
• Levels typically adjusted based on creatinine concentration

Clinical Applications

• Indicates severity and progression of osteoarthritis
• Useful in tracking rheumatoid arthritis joint damage
• Helps predict vulnerability to joint deterioration
• Beneficial in assessing sports injuries and joint developmental issues

Interpretation Considerations

• Requires context of age, existing health conditions, and medications
• Most effective when combined with other biomarkers and clinical evaluations
• Ongoing research aims to improve measurement precision