ABSTRACT
To evaluate the possible relation between serum levels of cartilage oligomeric matrix protein COMP, sTNF-RII, IL-6 and estradiol in post-menopausal females with clinically and radiologically documented osteoarthritic changes in the knee joint. Twenty post-menopausal females [PMOA] -with clinically and radiologically documented knee joint osteoarthritis were compared to a control group of ten post-menopausal females [control group [I]] and ten pre-menopausal females [control group [2]] "who were clinically and radiologically free of knee joint osteoarthritis. To all the studied subjects, a complete clinical examination was performed, including body mass index calculation, as well as scoring .systems for functional assessment of joint. Plain X-ray of both knee joints was performed. Serum samples were obtained for analysis of urea, creatinine, uric acid, total calcium, inorganic phosphates, C-reactive protein, rheumatoid factor COMP, sTNF-fUI, IL-6, and estradiol levels. The mean serum estradiol values in the PMOA, and control group [I] were significantly lower than their corresponding value in control group [2], and slightly lower in the PMOA than control group [1]. The mean serum COMP value was slightly higher in the PMOA group than its corresponding value in control group [1], and both mean sera values were significantly higher than their corresponding mean value in control group [2]. The mean serum sTNF-RII value was significantly higher in the PMOA group than its corresponding values in control group [1] and control group [2]. As regards mean serum IL-6 value, it was significantly higher in control group [1] than its corresponding values in the both PMOA and control group [2]. Based on ROC curve analysis in PMOA and control group [1], both serum COMP and sTNF-RII yitld a diagnostic specificity of 90% each, while the diagnostic sensitivity was 45% and 50% respectively. By using the combined approach, we were able to increase the diagnostic sensitivity of serum COMP and sTNF-RII to 90% and 83% respectively. On the other hand, the receiver operating characteristics [ROC] curve analysis of the same parameters in PMOA and control group [2], revealed a diagnostic sensitivity of 100% for each of serum COMP and s TNF-PJI as well as a diagnostic specificity of 90% for serum COMP and 70% for sTNF-RII. The fact that radiographic evidence of OA usually appears in advanced stages of the disease led to the need of identifying possible serum biochemical markers that could reflect the joint tissue status. From the above mentioned results, it could be concluded that the combined measurement of serum levels of the biochemical markers COMP and sTNF-RII may be used in identifying osteoarthritis in post-menopausal females. Furthermore, menopausal state per-se could play a role in the limitation of the diagnostic sensitivity of either of the two parameters if one of both analytes was chosen alone for measurement