RELATIONSHIP BETWEEN SERUM CARTILAGE OLIGOMERIC MATRIX PROTEIN LEVELS AND DISEASE PROGRESSION IN OSTEOARTHRITIS OF THE KNEE JOINT

The value of serum cartilage oligomeric matrix protein (COMP)as a marker of disease progression was investigated in 81 hospitalout-patients with clinical knee osteoarthritis (OA). Progressingpatients were defined by a decrease of     

CYTIDINE DEAMINASE AND LACTOFERRIN IN INFLAMMATORY SYNOVIAL FLUIDS. INDICATORS OF LOCAL POLYMORPHONUCLEAR CELL FUNCTION?

Cytidine deaminase (CD) is a cytoplasmatic enzyme present predominantlyin polymorphonuclear cells (PMNC) in inflamed joints. Lactoferrinis situated in the secondary granules of PMNC and is releasedby secretory/phagocytic stimuli, whereas CD is released mainlyupon cell lysis. To study the release of these molecules inarthritic conditions we measured CD and lactoferrin levels insynovial fluid (SF) drawn from patients with rheumatoid arthritis(RA), crystal pyrophos phate disease (CPPD), psoriatic arthropathy,reactive arthritis, spondylarthropathy, and osteoarthrosis.CD activity was highest in SF from RA and CPPD followed by psoriaticarthropathy, reactive arthritis and spondylarthropathy. Lactoferrinconcentrations were highest in CPPD followed by RA, reactivearthritis, psoriatic arthropathy, and spondyl arthropathy. BothCD and lactoferrin levels were low in osteoarthrosis SF. AlthoughSF CD activity and lactoferrin levels correlated well in alldiagnostic groups, the ratio between CD and lactoferrin washigher for RA, psoriatic arthropathy, and spondylarthropathycompared to reactive arthritis and CPPD. This suggests predominantrelease by PMNC lysis in the more chronic arthritis groups andmore degranulation in the more episodic CPPD and reactive arthritisgroups. CD activity and lactoferrin levels correlated significantlywith SF cell counts in the RA and psoriatic arthropathy groups. KEY WORDS: Synovial fluid, Arthritis, Osteoarthrosis, Lactoferrin, Cytidine deaminase, Leucocytes, Polymorphonuclear cells     

CARTILAGE OLIGOMERIC MATRIX PROTEIN: A NOVEL MARKER OF CARTILAGE TURNOVER DETECTABLE IN SYNOVIAL FLUID AND BLOOD

Cartilage oligomeric matrix protein (COMP) is a tissue specificnon-collagenous matrix protein. We have developed an enzyme-linkedimmunosorbent assay for the detection of this protein in synovialfluid and serum. The protein has been quantified in these fluidsin patients with rheumatoid arthritis (RA), reactive arthritis,juvenile chronic arthritis, osteoarthritis and in sera of controlsubjects. The protein was detectable in all fluids and the synovialfluid levels were always higher than in serum in paired samples.The highest knee joint synovial fluid levels were found in reactivearthritis patients and the lowest in RA patients with advanceddestruction of the knee joint. However, the relative synovialfluid content of COMP was higher in these RA patients than inpatients with advanced osteoarthritis. In patients with longstandingreactive synovitis the concentrations decreased. This decrease,however, was less marked than for proteoglycan concentrations. The serum concentrations were low in patients with juvenilechronic arthritis and in patients with RA with advanced cartilagedestruction of the studied knee joint. In the other groups serumlevels did not differ between groups or from controls. KEY WORDS: Cartilage matrix, Noncollagenous protein, Rheumatoid arthritis, Proteoglycans     

INCREASED SERUM CONCENTRATIONS OF CARTILAGE OLIGOMERIC MATRIX PROTEIN. A PROGNOSTIC MARKER IN EARLY RHEUMATOID ARTHRITIS

Two cartilage specific macromolecules, cartilage oligomericmatrix protein (COMP) and proteoglycan, were quantified by immunoassayin sera of two groups of patients with rheumatoid arthritis(RA) of recent onset to evaluate the prognostic value of suchmeasurements. Patients with rapidly progressive joint destructionhad increased COMP concentrations initially, which subsequentlydecreased. A group with more benign disease, and less extensivejoint damage, had normal COMP levels throughout the study period.Serum concentrations of proteoglycan were normal in both groups.Thus measurement of COMP in serum early in the course of RAholds promise as a prognostic marker for development of jointdestruction in this disease KEY WORDS: Non-collagenous cartilage matrix protein, Proteoglycan, Prognosis, Joint destruction