Ⅱ型胶原羧基端端肽对骨关节炎早期诊断和病情评估的实验研究

An experimental study of C telopeptide of type Ⅱ collagen for early diagnosis and condition evaluation of osteoarthritis

目的:定量检测骨关节炎(OA)大鼠模型血清、关节软骨蛋白提取液中Ⅱ型胶原羧基端端肽(CTX-Ⅱ)的变化,探讨其作为OA早期诊断及病情评估指标的价值和意义。方法:SD大鼠行前交叉韧带切断术诱导OA模型,将大鼠随机分为模型组和假手术组。于造模后不同时间点分批取血并处死取关节标本,检测血清及软骨蛋白提取液中CTX-Ⅱ水平,观察病理变化。结果:模型组术后2周开始出现OA特征性病理变化且逐渐加重,CTX-Ⅱ水平在术后3天开始不断升高。两组血清及软骨蛋白提取液中CTX-Ⅱ水平在造模后各时间点均有统计学差异,血清和软骨蛋白提取液中CTX-Ⅱ水平变化具有相关性。结论:在大鼠OA模型中,血清CTX-Ⅱ水平在未出现明显病理变化时即已开始增高,并与病灶区软骨中CTX-Ⅱ表达一致,可作为OA早期诊断和病情评估的参考指标。

Objective：To observe the expression of C telopeptide of type Ⅱcollagen（CTX-Ⅱ）in serum and protein extract from joints of experimental osteoarthritis（OA）,and to explore the value of CTX-Ⅱ as a biomarker in early diagnosis and condition assessment.Methods：96 adult SD rats were randomly divided into two groups：Sham-operated group（n=48）,OA model group（n=48）.OA was induced by unilateral surgical transection of the anterior cruciate ligament.Joints were isolated 0,3days,1,2,4,8weeks after surgery for protein extraction and histology.CTX-Ⅱ in protein extracts and serum was measured by ELISA.Results：Levels of CTXⅡ in serum and protein extract were both significantly increased in OA model group compared with sham-operated group on each time point.The pathological features of OA were observed during 2～8 weeks and became gradually more serious.The changes in level of CTX-Ⅱ in serum and protein extraction showed a close correlation.Conclusion：Serum CTX-Ⅱ level increases before the appearance of characteristic pathology of OA and is in coincidence with the changes of CTX-Ⅱ in the tissue.It can be a sensitive reference indicator for early diagnosis and condition evaluation of OA.