In end stage osteoarthritis, cartilage tissue pentosidine levels are inversely related to parameters of cartilage damage.
OBJECTIVE
Age is the most prominent predisposition for development of osteoarthritis (OA). Age-related changes of articular cartilage are likely to play a role. Advanced glycation endproducts (AGEs) accumulate in cartilage matrix with increasing age and adversely affect the biomechanical properties of the cartilage matrix and influence chondrocyte activity. In clinical studies AGEing of cartilage and its relation to actual cartilage damage can only be measured by surrogate markers (e.g., serum, skin or urine AGE levels and imaging or biochemical markers of cartilage damage). In this study actual cartilage AGE levels were directly related to actual cartilage damage by use of cartilage obtained at joint replacement surgery.


METHODS
Cartilage and urine samples were obtained from 69 patients undergoing total knee replacement. Samples were analyzed for pentosidine as marker of AGE. Cartilage damage was evaluated macroscopically, histologically, and biochemically.


RESULTS
Cartilage and urine pentosidine both increased with increasing age. The higher the macroscopic, histological, and biochemical cartilage damage the lower the cartilage pentosidine levels were. In multiple regression analysis age is not found to be a confounder.


CONCLUSIONS
There is an inverse relation between cartilage AGEs and actual cartilage damage in end-stage OA. This is likely due to ongoing (ineffective) increased turnover of cartilage matrix proteins even in end stage disease.
Rheumatology & Clinical Immunology, University Medical Centre Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands.
P A J M
PA
Vos
S C
SC
Mastbergen
A M
AM
Huisman
T N
TN
de Boer
J
J
DeGroot
A A
AA
Polak
F P J G
FP
Lafeber
D000368:Aged; D000375:Aging / Q000378:metabolism; D001120:Arginine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000652:urine; D019645:Arthroplasty, Replacement, Knee; D015415:Biomarkers / Q000378:metabolism / Q000652:urine; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D005260:Female; D017127:Glycation End Products, Advanced / Q000378:metabolism / Q000652:urine; D006801:Humans; D007719:Knee Joint / Q000378:metabolism / Q000473:pathology; D008239:Lysine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000652:urine; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D012720:Severity of Illness Index
D015415:Biomarkers; D017127:Glycation End Products, Advanced; D003094:Collagen; D001120:Arginine; C062187:pentosidine; D008239:Lysine