Cartilage Oligomeric Matrix Protein Human ELISA

Research topic

Bone and cartilage metabolism

Features

• It is intended for research use only.
• The total assay time is less than 3.5 hours.
• The kit measures COMP in serum and plasma (EDTA, citrate, heparin).
• Standard is recombinant protein based.
• Quality Controls are human serum based.
• Components of the kit are provided ready to use, concentrated and lyophilized.

Storage/Shipping

Store the kit at 2–8°C. Under these conditions, the kit is stable until the expiration date (see label on the box).

Summary

Cartilage oligomeric matrix protein (COMP), also designated thrombospondin 5 (TSP 5), is non-collagenous glycoprotein and is a member of the thrombospondin family of extracellular proteins. COMP is a calcium-binding protein of high molecular weight (>500kDa) present in the extracellular matrix of articular, nasal and tracheal cartilage. COMP is not only cartilage-derived but was found widely in other tissues, including synovium and tendon. Intact COMP is pentameric, with five identical subunits and the carboxy-terminal globular domain of native COMP binds to collagens I, II, and IX. It has been proposed that COMP molecules are important for maintaining the properties and integrity of collagen network. In addition COMP may have a storage and delivery function for hydrophobic cellsignaling molecules such as vitamin D. The significance of COMP for normal development and function of cartilage has been underscored by the discovery that mutations of the COMP gene result in pseudoachondro­plasia and some forms of multiple epiphyseal dysplasia. Most published studies have shown that serum levels of COMP provide important information about metabolic changes occurring in the cartilage matrix in joint disease. These studies describe that serum COMP level correlated with cartilage degradation and is a potential prognostic marker in inflammatory joint diseases such as osteoarthritis (OA) and rheumatoid arthritis (RA). Results have demonstrated an association of increasing serum COMP levels with progressive destruction of articular cartilage monitored radiographically. OA and RA are a common disease causing pain and disability in a significant proportion of the adult population and early diagnostics of these diseases is very important for future therapy.

Assay format

Sandwich ELISA, Biotin-labelled antibody

Sample requirements

5 µl/well

Applications

Plasma-Citrate, Plasma-EDTA, Plasma-Heparin, Serum

Calibration Curve

Calibration range

4 to 128 ng/ml

Limit of detection

Limit of Detection (LOD) (defined as concentration of analyte giving absorbance higher than mean absorbance of blank* plus three standard deviations of the absorbance of blank: Ablank + 3×SDblank) is calculated from the real COMP values in wells and is: 0.5 ng/ml.

Limit of quantification

Limit of assay Results exceeding COMP level of 128 ng/ml should by repeated with more diluted samples. Dilution factor needs to be taken into consideration in calculating the COMP concentration.

Intra-assay (Within-Run, n=8)

CV = 5.9 %

Inter-assay (Run-to-Run, n=8)

CV = 5.8%

Spiking Recovery

91.3 %

Dilution Linearity

95.8 %

Cross-Reactivity

Human

References to this product

• Stabler T, Fang F, Jordan J, Vilim V, Kraus VB . A comparison of methods for measuring cartilage oligomeric protein (COMP) in human subjects with knee OA.
• Bruyere O, Collette JH, Ethgen O, Rovati LC, Giacovelli G, Henrotin YE, Seidel L, Reginster JY. Biochemical markers of bone and cartilage remodeling in prediction of longterm progression of knee osteoarthritis. J Rheumatol. 2003 May;30 (5):1043-50
• Vilim V, Lenz ME, Vytasek R, Masuda K, Pavelka K, Kuettner KE, Thonar EJ. Characterization of monoclonal antibodies recognizing different fragments of cartilage oligomeric matrix protein in human body fluids. Arch Biochem Biophys. 1997 May 1;341 (1):8-16
• Jordan JM, Luta G, Stabler T, Renner JB, Dragomir AD, Vilim V, Hochberg MC, Helmick CG, Kraus VB. Ethnic and sex differences in serum levels of cartilage oligomeric matrix protein: the Johnston County Osteoarthritis Project. Arthritis Rheum. 2003 Mar;48 (3):675-81
• Misumi K, Vilim V, Clegg PD, Thompson CC, Carter SD. Measurement of cartilage oligomeric matrix protein (COMP) in normal and diseased equine synovial fluids. Osteoarthritis Cartilage. 2001 Feb;9 (2):119-27
• Vilim V, Voburka Z, Vytasek R, Senolt L, Tchetverikov I, Kraus VB, Pavelka K. Monoclonal antibodies to human cartilage oligomeric matrix protein: epitope mapping and characterization of sandwich ELISA. Clin Chim Acta. 2003 Feb;328 (1-2):59-69
• Dragomir AD, Kraus VB, Renner JB, Luta G, Clark A, Vilim V, Hochberg MC, Helmick CG, Jordan JM. Serum cartilage oligomeric matrix protein and clinical signs and symptoms of potential pre-radiographic hip and knee pathology. Osteoarthritis Cartilage. 2002 Sep;10 (9):687-91
• Vilim V, Vytasek R, Olejarova M, Machacek S, Gatterova J, Prochazka B, Kraus VB, Pavelka K. Serum cartilage oligomeric matrix protein reflects the presence of clinically diagnosed synovitis in patients with knee osteoarthritis. Osteoarthritis Cartilage. 2001 Oct;9 (7):612-8
• Vilim V, Olejarova M, Machacek S, Gatterova J, Kraus VB, Pavelka K. Serum levels of cartilage oligomeric matrix protein (COMP) correlate with radiographic progression of knee osteoarthritis. Osteoarthritis Cartilage. 2002 Sep;10 (9):707-13