Published in Volume
102, Issue 12
(December 15, 1998)J Clin Invest.
1998, The American Society for
Evidence for altered synthesis of type II collagen in patients with osteoarthritis.
Joint Diseases Laboratory, Shriners Hospitals for Children, Division of Surgical Research, Department of Surgery, McGill University, Montreal, Quebec, H3G 1A6, Canada.
Published December 15, 1998
There is evidence to suggest that the synthesis of type II collagen is increased in osteoarthritis (OA). Using an immunoassay, we show that the content of the C-propeptide of type II procollagen (CPII), released extracellularly from the newly synthesized molecule, is directly related to the synthesis of this molecule in healthy and osteoarthritic articular cartilages. In OA cartilage, CPII content is often markedly elevated (mean 7.6-fold), particularly in the mid and deep zones, reaching 29.6% of the content in newborn. Synthesis is also directly related to total collagen II content in OA, suggesting its importance in maintaining collagen content and cartilage structure. The release of CPII from cartilage is correlated directly with cartilage content. However, the increase in CPII in OA cartilage is not reflected in serum, where a significant reduction is observed. Together these studies provide evidence for alterations in procollagen II synthesis in vivo in patients with OA.