Serum keratan sulfate is a promising marker of early articular cartilage breakdown.
OBJECTIVE
To find serum markers that may serve as indices for an early diagnosis of degeneration or damage of the articular cartilage.


METHODS
Twenty-four healthy volunteers, 19 individuals with knee trauma (KT) and 31 with knee osteoarthritis (OA) were evaluated. KT patients were divided into a group (n = 5) with an injury <2 months old (recent KT) and a group (n = 14) with that >2 months old (old KT). Articular cartilage damage was assessed using either arthroscopy or direct observation. Serum concentrations of hyaluronic acid (HA), cartilage proteoglycan aggrecan turnover epitope (CS846) and cartilage oligomeric protein (COMP) were measured using enzyme-linked immunosorbent assay kits and those of keratan sulfate (KS) and chondroitin-6-sulfate (C6S) using high-performance liquid chromatography.


RESULTS
Serum KS in the recent KT group (2095 +/- 594 ng/ml) was significantly higher than that in the old KT group (1373 +/- 418 ng/ml; P = 0.021), and serum COMP in the recent KT group (1572 +/- 182 ng/ml) showed a tendency that was higher than that in the old KT group (1350 +/- 250 ng/ml; P = 0.079). Serum KS in OA patients with Kellgren and Lawrence (KL) grades 0 and I (1456 +/- 334 ng/ml) showed a tendency that was higher than that in OA patients with KL grades II, III and IV (1248 +/- 220 ng/ml; P = 0.084).


CONCLUSIONS
The serum concentration of KS correlated with the damage of the articular cartilage and it was significantly increased even at an early stage after the injury.
Wakitani
S
S
Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi, Abeno-ku, Osaka 545-8585, Japan. wakitani@med.osaka-cu.ac.jp
Nawata
M
M
Kawaguchi
A
A
Okabe
T
T
Takaoka
K
K
Tsuchiya
T
T
Nakaoka
R
R
Masuda
H
H
Miyazaki
K
K
D000328:Adult; D000368:Aged; D001182:Arthroscopy; D015415:Biomarkers / Q000097:blood; D002357:Cartilage Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D064236:Cartilage Oligomeric Matrix Protein; D002358:Cartilage, Articular / Q000293:injuries / Q000378:metabolism*; D002809:Chondroitin Sulfates / Q000097:blood; D016326:Extracellular Matrix Proteins / Q000097:blood; D005260:Female; D006023:Glycoproteins / Q000097:blood; D006801:Humans; D007632:Keratan Sulfate / Q000097:blood*; D007718:Knee Injuries / Q000175:diagnosis*; D008297:Male; D064235:Matrilin Proteins; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011859:Radiography
D015415:Biomarkers; D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; C577553:TSP5 protein, human; D002809:Chondroitin Sulfates; D007632:Keratan Sulfate