Increased urinary type II collagen C-telopeptide levels in Tunisian patients with knee osteoarthritis

Osteoarthritis is characterized by a progressive degeneration of articular cartilage and loss of joint function. Clinical assessment of osteoarthritis is hampered by the lack of accurate measures of disease and disease progression, especially during the early stage.

To investigate urinary C-telopeptide fragments of type II collagen (CTX-II) levels in knee osteoarthritis in the Tunisian population compared with controls and to assess the association between this biomarker and radiological signs.

One hundred and twenty five female patients with knee osteoarthritis, aged 53.6 +/- 7.6 years with disease duration of 3.6 +/- 3.8 years and 57 female age-matched controls underwent Lyon Schuss X-ray exams. Two experienced readers independently measured the joint space width (JSW) and classified each knee for severity using the Kellgren/Lawrence scale. The urinary concentration of CTX-II was measured by a competitive ELISA.

The levels of urinary CTX-II were significantly higher in knee osteoarthritis patients compared with controls (323.98 vs 218.04 microg/mol creatinine). A weak and non significant association between the CTX-II level and JSW was found. The significant correlations were observed between age and CTX-II in both groups and between BMI and CTX-II only in controls.

Analysis of CTX-II in urine samples of Tunisian patients with knee osteoarthritis provided a sensitive method to detect increased degradation of collagen type II in patients with osteoarthritis.