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

UNLABELLED: 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. BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

A 5-yr longitudinal study of type IIA collagen synthesis and total type II collagen degradation in patients with knee osteoarthritis--association with disease progression.

OBJECTIVES: The 5-yr longitudinal study tested the hypothesis that serum and urinary markers of type II collagen metabolism would be associated with radiological progression of disease in patients with mild-to-moderate knee osteoarthritis (OA). METHODS: Synthesis of type IIA collagen and degradation of total type II collagen were assessed in 135 patients with mild-to-moderate knee OA over 5 yrs using serum concentration of the N-propeptide of collagen type IIA (PIIANP) and urinary excretion of crosslinked C-telopeptide (CTX-II), respectively. The markers were measured at baseline, 2, 3 and 5 yrs' follow-up corresponding to X-ray time points. Analysis of variance (ANOVA) was performed to determine longitudinal changes over 5 yrs in the biomarkers in all patients and between progressors and non-progressors. RESULTS: Complete X-ray progression data over 5 yrs, serum PIIANP and urinary CTX-II were available for 84/135 patients. There were 24 progressors and 60 non-progressors. Overall, over the 5-yr study period average PIIANP and CTX-II levels were higher in progressors compared with non-progressors (P < 0.05 for both, ANOVA). The patients with serum PIIANP in the highest quartile of 5-yr levels of PIIANP had a significantly higher risk of progression than the other patients [relative risk (95% CI): 3.2 (1.1-9.2)]. Increased levels of urinary CTX-II were also associated with a higher risk of progression with a relative risk (95% CI) of 3.4 (1.2-9.4) in patients with 5-yr levels above the median. The risk of progression was highest in patients with 5-yr levels of PIIANP in the highest quartile and/or CTX-II in the two highest quartiles with a relative risk (95% CI) of progression, 11.8 (2.5-54). CONCLUSIONS: The data presented here suggest that progression of knee OA is associated with alterations of systemic levels of biological markers of type II collagen metabolism. The data also suggest that the combined measurement of serum PIIANP and urinary CTX-II may be useful to identify patients with knee OA at increased risk of disease progression.

Increased urinary type II collagen helical and C telopeptide levels are independently associated with a rapidly destructive hip osteoarthritis.

OBJECTIVES: Biochemical markers reflecting the degradation of the type II collagen helical (Helix-II) and type II collagen C telopeptides (CTX-II) have been developed. AIM: To investigate the association of rapidly destructive hip osteoarthritis with urinary Helix-II and urinary CTX-II. PATIENTS AND METHODS: 12 patients (mean age 70 years) meeting the criteria for rapidly destructive hip osteoarthritis and 28 patients with slowly progressive hip osteoarthritis (mean age 63 years) defined as <0.20 mm joint space loss/year were included in a case-control study. In each patient, urinary Helix-II and CTX-II were measured at the end of the follow-up period, with retrospective evaluation of x rays. RESULTS: Helix-II levels were 41% (p = 0.002) higher in the 40 patients with hip osteoarthritis than in 75 healthy controls. Increased Helix-II levels were associated with decreased minimum joint space width of the hip (r = -0.57, p = 0.001). Mean urinary Helix-II levels were 71% higher in rapidly destructive than in slowly progressive disease (mean (standard deviation (SD)) ng/mmol Cr: 396 (160) v 232 (118) ng/mmol; p = 0.002). When levels of Helix-II and CTX-II in the highest tertile were both included in a multivariate logistic regression model, high Helix-II level (OR; (95% CI) 5.73 (1.01 to 32.8)) after adjustment for age and body mass index and high CTX-II level (6.67 (1.14 to 39.0)) were, independently of each other, associated with a rapidly destructive disease. CONCLUSION: Increased urinary Helix-II levels are associated with rapidly destructive hip osteoarthritis, independently of urinary CTX-II. Measurement of Helix-II, alone or in combination with CTX-II, could be useful for the clinical investigation of patients with hip osteoarthritis.

Production and characterization of monoclonal antibodies against vegetative cells of Bacillus cereus.

Two monoclonal antibodies (MAbs) against Bacillus cereus were produced. The MAbs (8D3 and 9B7) were selected by enzyme-linked immunosorbent assay for their reactivity with B. cereus vegetative cells. They reacted with B. cereus vegetative cells while failing to recognize B. cereus spores. Immunoblotting revealed that MAb 8D3 recognized a 22-kDa antigen, while MAb 9B7 recognized two antigens with molecular masses of approximately 58 and 62 kDa. The use of MAbs 8D3 and 9B7 in combination to develop an immunological method for the detection of B. cereus vegetative cells in foods was investigated.