Correlation between urinary and synovial pyridinoline crosslinks and rheumatoid disease activity

Abstract EN

Objective: To measure pyridinoline cross-links in the urine and synovial fluid of rheumatoid arthritis (RA) patients as an index of cartilage destruction and correlate its level with the parameters of disease activity.

Chronic joint disease, as RA is characterized by alterations in the extracellular matrix metabolism of articular cartilage, collagen and proteoglycan being the major components of which.

Collagen fibers form a network, which maintains cartilage structure.

Cross-links in the collagen fibril network are believed to play various biochemical physiological roles in the extracellular matrix.

Pyridinoline a mature cross-link, is necessary for maintaining the structure of the matrix.

Material & Methods: The study was conducted on 50 patients suffering from RA who fulfilled the 1987 Revised American College of Rheumatology criteria for classification of RA and 10 healthy controls.

Patients were classified into 4 groups according to disease activity.

All patients were subjected to: full history taking, complete clinical examination with stress on the locomotory system, laboratory investigations including, blood picture, ESR, RF, synovial fluid analysis and measurement of pyridinoline levels in the urine and synovial fluid, as well as plain X-rays to the knees and hands.

Results: There was an increased level of urinary and synovial pyridinoline in RA patients than controls.

There was a significant correlation between pyridinoline levels in both synovial fluid and urine and the parameters of disease activity.

Also, synovial and urinary pyridinoline correlated significantly in most of the stages of the disease except for early stages.