One-year increase of Coll 2-1, a new marker of type II collagen degradation, in urine is highly predictive of radiological OA progression.
OBJECTIVE
To analyse the relationship between the levels of urinary biochemical markers of type II collagen degradation and the clinical and radiological severity and progression of knee osteoarthritis (OA).


METHODS
Seventy-five patients with primary knee OA were included in this 3-year follow-up study. Mean joint space width (JSW) of the medial compartment of the femorotibial joint was measured with a computer assisted method on standardized radiographs taken at baseline and after a 3-year follow-up. Pain, stiffness, and physical function subscales of the Western Ontario and McMaster Universities (WOMAC) were assessed at the same time points. Type II collagen peptides Coll 2-1 and Coll 2-1 NO(2), as well as pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) were measured in urines at baseline, after 1 year and 3 years, with specific immunoassays.


RESULTS
At baseline, significant correlations were found between the urinary Coll 2-1 and Coll 2-1 NO(2) levels and the global WOMAC score (Coll 2-1: r=0.28, P=0.01; Coll 2-1 NO(2): r=0.27, P=0.02) and its subscales for pain (Coll 2-1: r=0.27, P=0.01; Coll 2-1 NO(2): r=0.30, P=0.01) and function (Coll 2-1: r=0.29, P=0.01; Coll 2-1 NO(2): r=0.27, P=0.02). Pyr and D-Pyr levels were not significantly correlated with the WOMAC scores. One-year change in Coll 2-1 and Coll 2-1 NO(2) urinary levels were negatively correlated with a 3-year change in JSW (Coll 2-1: r=-0.31, P=0.03; Coll 2-1 NO(2): r=-0.31, P=0.03), indicating that an increase of Coll 2-1 or Coll 2-1 NO(2) over 1 year is predictive of subsequent joint space narrowing. Neither Pyr nor D-Pyr was correlated with radiological OA progression.


CONCLUSIONS
At baseline, Coll 2-1 and Coll 2-1 NO(2) urinary levels were indicative of the clinical activity of knee OA and the increase of these peptides over 1 year was predictive of the radiological progression of knee OA.
Deberg
M A
MA
University of Liege, Institute of Pathology, Level 5, Bone and Cartilage Research Unit, CHU Sart-Tilman, 4000 Liege, Belgium.
Labasse
A H
AH
Collette
J
J
Seidel
L
L
Reginster
J-Y
JY
Henrotin
Y E
YE
D000368:Aged; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers / Q000652:urine; D002358:Cartilage, Articular / Q000000981:diagnostic imaging; D024043:Collagen Type II / Q000378:metabolism* / Q000652:urine; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007719:Knee Joint; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000652:urine*; D010446:Peptide Fragments / Q000652:urine*; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted
D000596:Amino Acids; D015415:Biomarkers; D024043:Collagen Type II; D010446:Peptide Fragments; C510280:collagen type II (108-116); C510281:collagen type II (108-116), (NO2)Tyr(111)-; C015484:pyridinoline; C036020:deoxypyridinoline