Send to

Choose Destination
See comment in PubMed Commons below
Arthritis Res Ther. 2011 Feb 14;13(1):R22. doi: 10.1186/ar3246.

Relationships between biomarkers of cartilage, bone, synovial metabolism and knee pain provide insights into the origins of pain in early knee osteoarthritis.

Author information

Department of Medicine for Motor Organ, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.



We tested the hypothesis that there exist relationships between the onset of early stage radiographically defined knee osteoarthritis (OA), pain and changes in biomarkers of joint metabolism.


Using Kellgren-Lawrence (K/L) grading early radiographic knee OA (K/L 2) was detected in 16 of 46 patients. These grades (K/L 1 is no OA and K/L 2 is early OA) were divided into two groups according to the presence or absence of persistent knee pain. Sera (s) and urines (u) were analysed with biomarkers for cartilage collagen cleavage (sC2C and uCTX-II) and synthesis (sCPII), bone resorption (uNTx) and synovitis (hyaluronic acid: sHA).


sCPII decreased and sC2C/sCPII, uCTX-II/sCPII and sHA increased with onset of OA (K/L 2 versus K/L 1) irrespective of joint pain. In contrast, sC2C and uCTX-II remained unchanged in early OA patients. Of the patients with K/L grades 1 and 2 sC2C, sCPII, sHA, uNTX and uCTX-II were all significantly increased in patients with knee pain independent of grade. Among the K/L grade 2 subjects, only uCTX-II and uCTX-II/sCPII were increased in those with knee pain. In grade 1 patients both sC2C and sCPII were increased in those with knee pain. No such grade specific changes were seen for the other biomarkers including sHA.


These results suggest that changes in cartilage matrix turnover detected by molecular biomarkers may reflect early changes in cartilage structure that account directly or indirectly for knee pain. Also K/L grade 1 patients with knee pain exhibit biomarker features of early OA.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for BioMed Central Icon for PubMed Central
    Loading ...
    Support Center