High serum cartilage oligomeric matrix protein determines the subset of patients with early-stage rheumatoid arthritis with high serum C-reactive protein, matrix metalloproteinase-3, and MRI-proven bone erosion.
OBJECTIVE
To identify the significance of serum cartilage oligomeric matrix protein (COMP), a marker of cartilage turnover, in patients with early-stage rheumatoid arthritis (RA) in relation to other serologic variables and magnetic resonance imaging (MRI) features.


METHODS
Ninety-eight patients with early-stage RA, whose disease duration from onset was less than 2 years, were enrolled. The objective measures at baseline were Disease Activity Score (DAS28), serum C-reactive protein (CRP), serum matrix metalloproteinase-3 (MMP-3), serum antibodies against cyclic citrullinated peptide (anti-CCP), and MRI features of both wrist and finger joints. The MRI features included the number of sites scored positive for synovitis, bone edema, and bone erosion.


RESULTS
Serum COMP concentration was not different among groups identified with low, moderate, and high DAS28-CRP values. However, COMP values were statistically high in subjects positive for bone erosions on MRI compared with the subjects who were negative for bone erosions. A positive correlation of COMP with CRP and with MMP-3 values was also identified.


CONCLUSIONS
Elevation of COMP may reflect joint damage that is dependent on the synovial inflammatory process in early-stage RA.
Fujikawa
Keita
K
Unit of Translational Medicine, Department of Immunology and Rheumatology, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan.
Kawakami
Atsushi
A
Tamai
Mami
M
Uetani
Masataka
M
Takao
Shoichiro
S
Arima
Kazuhiko
K
Iwamoto
Naoki
N
Aramaki
Toshiyuki
T
Kawashiri
Shinya
S
Ichinose
Kunihiro
K
Kamachi
Makoto
M
Nakamura
Hideki
H
Origuchi
Tomoki
T
Ida
Hiroaki
H
Aoyagi
Kiyoshi
K
Eguchi
Katsumi
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000473:pathology / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D001842:Bone and Bones / Q000473:pathology*; D002097:C-Reactive Protein / Q000032:analysis*; D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins / Q000097:blood*; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006304:Health Status; D006801:Humans; D007596:Joints / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D064235:Matrilin Proteins; D019278:Matrix Metalloproteinase 3 / Q000097:blood*; D008875:Middle Aged; D012720:Severity of Illness Index; D013585:Synovitis / Q000473:pathology; D055815:Young Adult
D015415:Biomarkers; D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; C577553:TSP5 protein, human; D002097:C-Reactive Protein; D019278:Matrix Metalloproteinase 3