Increased levels of leukemia inhibitory factor in synovial fluid from patients with rheumatoid arthritis and other inflammatory arthritides.
OBJECTIVE
To examine synovial fluid (SF) from patients with arthritis, for the presence of the cytokine leukemia inhibitory factor (LIF).


METHODS
SF from 152 subjects was examined for LIF, using a radioreceptor competition assay.


RESULTS
LIF was present at concentrations of 1-43 ng/ml in the SF of 23% of patients with rheumatoid arthritis (RA) or other inflammatory or infectious arthritides but in only 1 of 29 patients with osteoarthritis (P < 0.01). In the RA patients, the SF LIF concentration correlated significantly with the peripheral blood white blood cell count (WBC) (P < 0.05) and the SF WBC count (P < 0.01), but not with other clinical or radiologic parameters of disease activity or progression.


CONCLUSIONS
LIF is implicated as a potential mediator of the local or systemic inflammatory response or the joint destruction seen in inflammatory arthritis.
Waring
P M
PM
Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Victoria, Australia.
Carroll
G J
GJ
Kandiah
D A
DA
Buirski
G
G
Metcalf
D
D
D001168:Arthritis / Q000378:metabolism*; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism*; D005528:Foot / Q000000981:diagnostic imaging; D006131:Growth Inhibitors / Q000032:analysis*; D006225:Hand / Q000000981:diagnostic imaging; D006801:Humans; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000032:analysis*; D011859:Radiography; D012720:Severity of Illness Index; D013582:Synovial Fluid / Q000737:chemistry*; D013997:Time Factors
D006131:Growth Inhibitors; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines