Experimental Study Of C Telopeptide Of Type Ⅱ Collagen: A Biomarker For Diagnosis And Evaluation Of Osteoarthritis

Objective:To observe the expression of C telopeptide of typeâ…¡collagen(CTX-â…¡)in serum and protein extract from joints of experimental osteoarthritis(OA),to study the value of CTX-â…¡as a biomarker in early diagnosis and condition assessment, and to explore the indicator in peripheral circulation of body to reflect the overall level of OA.Method:96 adult male SD rats were randomly divided into two groups: Sham-operated group (n=48),left knee group(n=48). OA was induced by left knee surgical transection of the anterior cruciate ligament in left knee group. Sham- operated group was given the same method above,but do not cut off the anterior cruciate ligament. Joints were isolated before surgery,after surgery 3days,1,2,4,8weeks for protein extraction,general observation and pathological observation . CTX-â…¡were measured in protein extracts and serum by ELISA. Another 24 rats were defined as both knees group with transection of the anterior cruciate ligament in bilateral knee. Its method is the same as the above, but time points were just before surgery,After surgery 2 weeks,8 weeks.Result:Levels of CTX-â…¡both in serum and protein extract began to increase since the point of 3days in left knee group,and they were significantly higher than in sham-operated group on each time point after surgery. The pathological features of OA were observed during 2~8 weeks and became gradually serious. The changes in levels of CTX-â…¡in both serum and protein extraction showed a close correlation. In the points of 2 weeks and 8 weeks after surgery,the levels of serum CTX-â…¡in both knees group were higher than in left knee and sham-operated group,and the differences were statistically significant.Conclusion:In the rat models of OA,Serum CTX-â…¡levels began to increase before the appearance of characteristic pathology of OA and in line with the levels in the tissue. It can be a sensitive reference indicator for early diagnosis and condition evaluation of OA. The CTX-â…¡levels in situ reflect the extent of local disease,while the levels in serum reflect the overall severity of OA. For both knees involved in OA, the index have a reference value in prediction and condition evaluation...