Receptor expression in synovial fluid neutrophils from patients with rheumatoid arthritis.
OBJECTIVE
The aim of this study was to determine if neutrophils isolated from the blood and synovial fluid of patients with rheumatoid arthritis had patterns of receptor expression resembling those of blood neutrophils from controls which had been activated and primed in vitro.


METHODS
Fluorescence activated cell sorting was used to measure receptor expression in paired blood and synovial fluid neutrophils from patients and in control neutrophils exposed to phorbol myristate acetate and granulocyte-macrophage colony stimulating factor.


RESULTS
There was no significant difference in the patterns of receptor expression in blood neutrophils from patients and healthy controls, but neutrophils in the synovial fluid had been primed and activated within the joint. About 50% of rheumatoid synovial fluid neutrophil samples expressed Fc gamma RI, a high affinity receptor for monomeric IgG, which is only expressed in neutrophils exposed to cytokines.


CONCLUSIONS
Synovial fluid neutrophils are activated and primed within the inflamed joint and hence their ability to respond to activating factors such as immune complexes will be modulated. As the expression of Fc gamma RI requires active biosynthesis, this work indicates that selective gene activation occurs when neutrophils are recruited into rheumatoid joints.
Watson
F
F
Department of Biochemistry, University of Liverpool, United Kingdom.
Robinson
J J
JJ
Phelan
M
M
Bucknall
R C
RC
Edwards
S W
SW
D015703:Antigens, CD / Q000032:analysis; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D018845:CD11 Antigens; D002478:Cells, Cultured; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology; D006801:Humans; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology*; D017463:Receptors, Complement 3b / Q000032:analysis; D017452:Receptors, IgG / Q000032:analysis; D011971:Receptors, Immunologic / Q000032:analysis*; D013582:Synovial Fluid / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015703:Antigens, CD; D018845:CD11 Antigens; D017463:Receptors, Complement 3b; D017452:Receptors, IgG; D011971:Receptors, Immunologic; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D013755:Tetradecanoylphorbol Acetate