Andersson M L E, Petersson I F, Karlsson K E, Jonsson E N, Månsson B, Heinegård D, Saxne T
Spenshult's Hospital for Rheumatic Diseases, Halmstad, Sweden.
Ann Rheum Dis. 2006 Nov;65(11):1490-4. doi: 10.1136/ard.2005.051292. Epub 2006 May 17.
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.
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.
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.
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.
监测24小时内血清软骨寡聚基质蛋白（COMP）浓度的变化，以确定是否存在昼夜变化，并估计有症状的膝骨关节炎患者和类风湿关节炎患者循环中COMP的半衰期。
对10例膝骨关节炎患者和14例类风湿关节炎患者每4小时采集一次血清样本（每位患者24小时内采集7份样本）。根据影像学和临床标准（美国风湿病学会（ACR）标准）定义骨关节炎，根据1987年ACR标准定义类风湿关节炎。采用夹心ELISA法检测血清COMP。使用计算机程序NONMEM建立COMP水平昼夜变化的统计模型。
两组在08:00至21:００日间期间，COMP水平均未观察到显著变化。夜间卧床休息时，骨关节炎患者和类风湿关节炎患者的血清COMP均显著下降，在04:00至05:00达到最低水平（与所有其他时间点相比，p<0.03或更低）。根据血清COMP水平的下降速率，估计循环中COMP的推定半衰期为7.4小时。
在正常日间活动期间，血清COMP水平保持恒定。夜间下降表明COMP一旦进入循环就会迅速清除。日间COMP水平稳定表明在临床实践中无需进一步规范血清采样时间。
