Studies On Tumor Necrosis Factor-α And Interleukin-6 Levels In Serum Associated With Clinical Significance In Patients With Knee Osteoarthritis

Object: To investigate the relationship between the levels of TNF-a and IL-6 in serum and the severity of knee osteoarthritis (KOA), as well as to analyze its effect in the processes of pathologic change of KOA and its reliability to reflect the severity of pathological change clinically in the early stage KOA patients.Methods: 52 cases of patients with knee osteoarthritis and 21 healthy cases were chosen as samples. X-ray were examined when the patients were ordered to stand on one foot. The patients were divided into the early, middle and late stage groups according to the results of X-ray inspection. Moreover, these patients of these groups received different treatment, respectively. Venous blood of both patients and healthy individual was sampled before and after treatment. Joint fluid of KOA patients was sampled before treatment. The levels of TNF-a and IL-6 in serum and joint fluid were analyzed using an Enzyme-linked immunosorbent assay (ELISA). Results:1 , The TNF-a and IL-6 levels in serum of KOA patients were significantly higher than those of healthy cases(P<0.01).2, The TNF-a and IL-6 levels of KOA patients rose significantly in the early stage, respectively. No statistical difference was observed between the TNF-a levels in the early and middle stage patients. Nevertheless, the TNF-a levels rose to the peak in the late stage patients. The IL-6 levels was the highest in middle stage patients, decreasing significantly in the late stage (P=0.00).3 , The IL-6 levesl was significantly reduce among all the staging treatment groups after treatment (P=0.00).No statistical reduce of TNF-a levels was obtained in patients of early stage group after treatment, while the TNF-a levels dropped significantly in patients of middle and late stage groups (P=0.00).4 . The levels of TNF-a in serum was demonstrated to be statistically correlated to the levels in joint fluid of KOA patients before receiving treatment (RNTF-a=0.74). Statistical correlation was found between the IL-6 levels in serum and joint fluid (RIL-6=0.73).Conclusions:1 . Both TNF-a and IL-6 are involved in the progression of osteoarthritis, and are closely correlated to severity of KOA. High levels of TNF-a and IL-6 were observed in both serum and joint fluid of KOA patients in current study, with the levels in serum and joint fluid statistically correlated. It was also found that the TNF-a and IL-6 levels reached to peak concentrations at different stages of KOA, respectively.2. The high levels of TNF-a in serum of KOA patients was proposed to be induced by the degeneration and flbrosis of synovial membrane. The high levels of IL-6 was considered to be related to the metabolism of cartilages.3. However, KOA patients of early or middle stage could not be distinguished by the serum level of TNF-a, therefore it could not be purposely used as a clinical reference index for KOA. But the serum level of IL-6 can be used for clinical reference index due to its higher expression in serum of early and middle stage patients than the healthy.