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- Andersson, M. L. E., et al.
(författare)
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Diurnal variation in serum levels of cartilage oligomeric matrix protein in patients with knee osteoarthritis or rheumatoid arthritis
- 2006
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 65:11, s. 1490-1494
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To monitor changes in serum concentrations of cartilage oligomeric matrix protein (COMP) during a 24-h period to determine any diurnal variation, and to estimate the half life of COMP in the circulation in patients with symptomatic knee osteoarthritis and in those with rheumatoid arthritis. Methods: Serum samples were drawn every 4 h (7 samples/patient over 24 h) in 10 patients with knee osteoarthritis and 14 patients with rheumatoid arthritis. Osteoarthritis was defined radiographically and clinically (American College of Rheumatology (ACR) criteria) and rheumatoid arthritis according to the 1987 ACR criteria. Serum COMP was measured by sandwich ELISA. A statistical model for the diurnal variation in the COMP levels was developed using the computer program NONMEM. Results: No considerable changes in COMP levels were observed during the day between 08:00 and 21:00 in either group. A significant decrease in serum COMP was apparent during bed rest at night, reaching the lowest levels between 04:00 and 05:00 (p < 0.03 or better v all other time points) in patients with osteoarthritis and in those with rheumatoid arthritis. From the rate of decreasing serum COMP levels, a putative half life of COMP in the circulation was estimated to be 7.4 h. Conclusion: During normal daytime activities, serum COMP levels are constant. The decrease during the night indicates a rapid elimination of COMP once it has reached the circulation. The stable COMP levels during the day suggest that it is not necessary to further standardise the time of serum sampling in clinical practice.
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| 2. |
- C Kapetanovic, Meliha, et al.
(författare)
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Serum cartilage oligomeric matrix protein (COMP) decreases in rheumatoid arthritis patients treated with infliximab or etanercept.
- 2003
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Ingår i: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1465-9905. ; 5:4, s. 181-185
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Tidskriftsartikel (refereegranskat)abstract
- Changes in serum cartilage oligomeric matrix protein (COMP) were studied during a 6-month period from initiation of treatment of rheumatoid arthritis patients with either infliximab or etanercept, to elucidate whether the favourable results of tissue protection reported in clinical trials are corroborated by changing levels of circulating COMP. Rheumatoid arthritis patients commencing treatment with infliximab (N = 32) or etanercept (N = 17) were monitored in accordance with a structured protocol. Only patients who were not receiving glucocorticoids or who were on a stable dose of oral prednisolone (<10 mg daily) were included. Serum COMP was measured by a sandwich immunoassay based on two monoclonal antibodies against human COMP in samples obtained at treatment initiation and at 3 and 6 months. Serum COMP decreased at 3 months in both infliximab- and etanercept-treated patients (P < 0.001 and <0.005, respectively) and remained low at 6 months. There was no significant correlation between changes in or concentrations of serum COMP and serum C-reactive protein at any time point. A decrease in serum COMP was seen both in ACR20 responders (patients meeting the American College of Rheumatology criteria for 20% improvement) and in nonresponders. The pattern of changes of serum COMP, a marker for cartilage turnover, in these patient groups supports the interpretation that infliximab and etanercept have a joint protective effect. Serum COMP has potential as a useful marker for evaluating tissue effects of novel treatment modalities in rheumatoid arthritis.
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| 3. |
- Månsson, Bengt, et al.
(författare)
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Association of chondroadherin with collagen type II
- 2001
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 276:35, s. 32883-32888
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Tidskriftsartikel (refereegranskat)abstract
- Chondroadherin is a cell binding, leucine-rich repeat protein found in the territorial matrix of articular cartilage. Several members of the leucine-rich repeat protein family present in the extracellular matrix of e.g. cartilage have been shown to interact with collagen and influence collagen fibrillogenesis. We show that complexes of monomeric collagen type II and chondroadherin can be released under non-denaturing conditions from articular cartilage treated with p-aminophenylmercuric acetate to activate resident matrix metalloproteinases. Purified complexes as well as complexes formed in vitro between recombinant chondroadherin and collagen type II were studied by electron microscopy. Chondroadherin was shown to bind to two sites on collagen type II. The interaction was characterized by surface plasmon resonance analysis showing K(D) values in the nanomolar range. Both chondroadherin and collagen interact with chondrocytes, partly via the same receptor, but give rise to different cellular responses. By also interacting with each other, a complex system is created which may be of functional importance for the communication between the cells and its surrounding matrix and/or in the regulation of collagen fibril assembly.
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| 6. |
- Månsson, Bengt, et al.
(författare)
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Release of cartilage and bone macromolecules into synovial fluid: differences between psoriatic arthritis and rheumatoid arthritis
- 2001
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 60:1, s. 27-31
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To elucidate whether differences in the destructive tissue process in cartilage and bone in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) can be recognised by different release patterns of molecular fragments derived from joint tissue. METHODS: Aggrecan, cartilage oligomeric matrix protein (COMP), and bone sialoprotein (BSP) were quantified by immunoassays in knee joint synovial fluid samples. These were obtained early in the disease course of patients with PsA and RA. At the time of arthrocentesis radiographs of their knee and hip joints were normal. RESULTS: At follow up no destruction had developed in the knees and hips of most patients with PsA (n=18), whereas the patients with RA could be separated into one "destructive" group (n=18) and one "non-destructive" group (n=25). Patients with PsA had low synovial fluid aggrecan concentrations (p<0.001 v the RA destructive group) but high COMP concentrations (p<0.01 and p<0.05 v destructive and non-destructive RA groups, respectively). Consequently, the aggrecan/COMP ratio was lowest in the PsA group (p<0.001 and p<0.01 v the destructive and non-destructive RA group, respectively). The synovial fluid concentrations of BSP did not differ between the three patient groups. CONCLUSIONS: The release pattern of aggrecan and COMP, reflecting cartilage turnover, differed between the PsA group and, particularly, the destructive RA group. This suggests that different pathophysiological mechanisms for cartilage involvement operate in these conditions, with different destructive potential. The BSP concentrations did not differ between the patients groups, which indicates similar levels of bone involvement.
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