Aim of the work: To determine the relation between knee synovitis detected by ultrasound (US) and biomarkers of inflammation and oxidative stress in primary knee osteoarthritis (KOA) patients. Patients and methods The study included 40 patients with primary KOA and 40 age and sex matched control. Patients were evaluated using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Laboratory investigations included high-sensitivity C-reactive protein (hsCRP), matrix metalloproteinase-mediated breakdown of CRP (CRPM), nitric oxide (NO), hydrogen peroxide (H2O2) and malondialdehyde (MDA). High resolution US examination of knee joints (grey-scale and power Doppler) was done for assessment of synovitis. Results: The patients were 37 females and 3 males, the mean age was 45.5 ± 9.25 years, 50% were housewives. Tenderness was grade 1 in 45%, 2 in 40% and 3 in 15%; 82.5% has swelling and 87.5% had crepitus; the WOMAC score was 57 (5–112); pain-index 10 ± 4.2; stiffness index 6.0 ± 2.01 and physical function 41 ± 13.55. Sonographically, 29(72.5%) had grey-scale synovitis (effusion and synovial hypertrophy) and 5(12.5%) patients had a positive Doppler signal. The serum levels of the hsCRP, CRPM, NO, H2O2 and MDA were signficantly increased in the patients compared to the control (p < 0.001 for all). There was no significant difference of the studied laboratory parameters according to the presence and absence of the sonographic findings. Conclusions: Although the serum levels of both inflammatory and oxidative stress biomarkers were significantly higher in OA patients compared to the control, there was no correlation with the sonographic findings of synovitis.

Background: Osteoarthritis is the most common degenerative joint disease resulting in pain and altered joint function. Objective: We investigated the possible association between serum interleukin-6 and symptoms of knee osteoarthritis with regard to pain, stiffness, physical function, assessed by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). We also examined the connections between serum interleukin-6 and radiographic severity in primary knee osteoarthritis patients. Methods: In this case-control study, fifty primary knee osteoarthritis patients and fifty age and sex matched controls were randomly recruited. Serum interleukin-6 levels were immunoassayed in patients’ and controls’ serum. Patients’ knee pain, stiffness and physical function were assessed by the respective subscales of the WOMAC Index. Standing anteroposterior radiographs of the knee joint were performed and graded with the Kellegren-Lawrence grade. Results: The mean serum IL-6 level was significantly higher in osteoarthritis patients (110.22 ± 46.98pg/ml) than controls (46.04 ± 12.34 pg/ml) (p=0.001). The WOMAC Index in patients ranged from 0 – 95 and the Kellegren-Lawrence score mean was 2.7 ± 0.76. There was a significant correlation between serum IL-6 levels and pain (r=0.595 p=0.001), physical function score (r=0.666, p=0.001)), and the radiographic score (r=0.799, p=0.001). Regression analysis showed that IL-6 level had a greater impact on both the WOMAC Index (p=0.005) and the Kellegren-Lawrence score (p=0.01). Conclusion: Serum IL-6 level is increased in primary knee osteoarthritis patients. Also, serum interlukin-6 is significantly related to osteoarthritis symptoms and radiographic severity.