The role of synovial fluid markers of catabolism and anabolism in osteoarthritis, rheumatoid arthritis and asymptomatic organ donors

• Published in: Arthritis research & therapy 2011-03, Vol.13 (2), p.R50-R50, Article R50
• Main Authors: Kokebie, Rediet, Aggarwal, Rohit, Lidder, Sukhwinderjit, Hakimiyan, Arnavaz A, Rueger, David C, Block, Joel A, Chubinskaya, Susan
• Format: Article
• Language: English
• Subjects: Analysis; Arthritis, Rheumatoid - diagnosis; Arthritis, Rheumatoid - metabolism; Biological markers; Biomarkers - analysis; Biomarkers - metabolism; Blood cell count; Cytokines - analysis; Cytokines - metabolism; Development and progression; Diagnosis; Enzyme-Linked Immunosorbent Assay; Enzymes; Female; Humans; Identification and classification; Interleukins; Knee Joint - metabolism; Leukemia; Male; Medical research; Medicine, Experimental; Metabolism; Middle Aged; Osteoarthritis; Osteoarthritis - diagnosis; Osteoarthritis - metabolism; Rheumatoid arthritis; Rheumatoid factor; Synovial Fluid - chemistry; Synovial Fluid - metabolism; Tissue Donors; Transplantation of organs, tissues, etc
• ISSN: 1478-6362; 1478-6354; 1478-6362
• DOI: 10.1186/ar3293

The purpose of this study was to correlate the level of anabolic and catabolic biomarkers in synovial fluid (SF) from patients with rheumatoid arthritis (RA), patients with osteoarthritis (OA) and asymptomatic organ donors. SF was collected from the knees of 45 OA, 22 RA patients and 20 asymptomatic organ donors. Eight biomarkers were selected and analyzed by using an enzyme-linked immunosorbent assay: interleukin (IL)-1, IL-6, IL-8 and IL-11; leukemia-inhibitory factor (LIF); cartilage oligomeric protein (COMP); osteocalcin; and osteogenic protein 1 (OP-1). Data are expressed as medians (interquartile ranges). The effects of sex and disease activity were assessed on the basis of the Western Ontario and McMaster Universities index score for patients with OA and on the basis of white blood cell count, erythrocyte sedimentation rate and C-reactive protein level for patients with RA. The mean ages (± SD) of the patients were as follows: 53 ± 9 years for patients with OA, 54 ± 11 years for patients with RA and 52 ± 7 years for asymptomatic organ donors. No effect of participants' sex was identified. In the SF of patients with RA, four of five cytokines were higher than those in the SF of patients with OA and those of asymptomatic organ donors. The most significant differences were found for IL-6 and IL-8, where IL-6 concentration in SF of patients with RA was almost threefold higher than that in patients with OA and fourfold higher than that in asymptomatic donor controls: 354.7 pg/ml (1,851.6) vs. 119.4 pg/ml (193.2) vs. 86.97 pg/ml (82.0) (P < 0.05 and P < 0.05, respectively). IL-8 concentrations were higher in SF of patients with RA than that in patients with OA as well as that in asymptomatic donor controls: 583.6 pg/ml (1,086.4) vs. 429 pg/ml (87.3) vs. 451 pg/ml (170.1) (P < 0.05 and P < 0.05, respectively). No differences were found for IL-11 in the SF of patients with RA and that of patients with OA, while a 1.4-fold difference was detected in the SF of patients with OA and that of asymptomatic donor controls: 296.2 pg/ml (257.2) vs. 211.6 pg/ml (40.8) (P < 0.05). IL-1 concentrations were the highest in the SF of RA patients (9.26 pg/ml (11.1)); in the SF of asymptomatic donors, it was significantly higher than that in patients with OA (9.083 pg/ml (1.6) vs. 7.76 pg/ml (2.6); P < 0.05). Conversely, asymptomatic donor control samples had the highest LIF concentrations: 228.5 pg/ml (131.6) vs. 128.4 pg/ml (222.7) in the SF of patients with RA vs. 107.5 p