Quantitative analysis of crosslinks pyridinoline and pentosidine in articular cartilage of patients with bone and joint disorders

Abstract
Objective. To determine the content of two crosslinks, pyridinoline (a mature crosslink) and pentosidine (a senescent crosslink), in human articular cartilage, and to examine the effect of bone and joint disorders on the content of those crosslinks in articular cartilage. Methods. After pretreatment with SP-Sephadex C-25, high-performance liquid chromatography was conducted on a hydrolysate of human articular cartilage from 53 patients with one of the following diseases: osteoarthritis (OA), rheumatoid arthritis (RA), osteoporosis, femoral head necrosis, and renal osteodystrophy (ROD). Results. Pyridinoline levels were either unchanged with age or were slightly decreased in elderly patients. Pentosidine levels increased with age in the entire patient population. There was no significant difference in the pyridinoline content among the study groups, but there was a significant difference in pentosidine content (P < 0.001). ROD patients had the highest mean level of pentosidine (407 μmoles/mole of hydroxyproline), and RA patients had a higher mean level than age-matched OA patients (214 versus 103 μmoles/mole of hydroxyproline). Conclusion. Bone and joint disorders do not affect the pyridinoline content in articular cartilage, but they do affect the pentosidine content.