Resistin in rheumatoid arthritis synovial tissue, synovial fluid and serum.
BACKGROUND
Resistin is a newly identified adipocytokine which has demonstrated links between obesity and insulin resistance in rodents. In humans, proinflammatory properties of resistin are superior to its insulin resistance-inducing effects.


OBJECTIVE
To assess resistin expression in synovial tissues, serum and synovial fluid from patients with rheumatoid arthritis, osteoarthritis and spondylarthropathies (SpA), and to study its relationship with inflammatory status and rheumatoid arthritis disease activity.


METHODS
Resistin expression and localisation in synovial tissue was determined by immunohistochemistry and confocal microscopy. Serum and synovial fluid resistin, leptin, interleukin (IL)1beta, IL6, IL8, tumour necrosis factor alpha, and monocyte chemoattractant protein-1 levels were measured. The clinical activity of patients with rheumatoid arthritis was assessed according to the 28 joint count Disease Activity Score (DAS28).


RESULTS
Resistin was detected in the synovium in both rheumatoid arthritis and osteoarthritis. Staining in the sublining layer was more intensive in patients with rheumatoid arthritis compared with those with osteoarthritis. In rheumatoid arthritis, macrophages (CD68), B lymphocytes (CD20) and plasma cells (CD138) but not T lymphocytes (CD3) showed colocalisation with resistin. Synovial fluid resistin was higher in patients with rheumatoid arthritis than in those with SpA or osteoarthritis (both p<0.001). In patients with rheumatoid arthritis and SpA, serum resistin levels were higher than those with osteoarthritis (p<0.01). Increased serum resistin in patients with rheumatoid arthritis correlated with both CRP (r=0.53, p<0.02), and DAS28 (r=0.44, p<0.05), but not with selected (adipo) cytokines.


CONCLUSIONS
The upregulated resistin at local sites of inflammation and the link between serum resistin, inflammation and disease activity suggest a role for resistin in the pathogenesis of rheumatoid arthritis.
Senolt
L
L
Institute of Rheumatology, 1st Medical Faculty, Charles University, Na Slupi 4, 12850 Prague 2, Czech Republic, and University Hospital Giessen, Department of Internal Medicine and Rheumatology, Germany. seno@revma.cz
Housa
D
D
Vernerová
Z
Z
Jirásek
T
T
Svobodová
R
R
Veigl
D
D
Anderlová
K
K
Müller-Ladner
U
U
Pavelka
K
K
Haluzík
M
M
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D018836:Inflammation Mediators / Q000032:analysis; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000097:blood / Q000378:metabolism; D052243:Resistin / Q000032:analysis* / Q000097:blood; D012720:Severity of Illness Index; D025242:Spondylarthropathies / Q000097:blood / Q000378:metabolism; D013582:Synovial Fluid / Q000737:chemistry; D013583:Synovial Membrane / Q000737:chemistry*
D015415:Biomarkers; D018836:Inflammation Mediators; D052243:Resistin