Association between degree of bone-erosion and synovial fluid-levels of tumor necrosis factor alpha in the knee-joints of patients with rheumatoid arthritis.
OBJECTIVE
To determine whether concentrations of cytokines and matrix-degrading enzymes in synovial fluid of patients with rheumatoid arthritis or osteoarthritis are associated with the degree of bone-destruction in the same joint.


METHODS
Determination of Interleukin-1 alpha, IL-1 beta, IL-1-receptor-antagonist, IL-6, IL-8, tumor necrosis factor alpha (by ELISA), collagenase-activity and caseinase-activity (by substrate-assays) in the SF (knee) of patients with RA (n42) or OA (n35). The degree of bone-destruction was assessed radiographically.


RESULTS
SF cytokine- and enzyme-levels were higher in patients with RA than in those with OA. In the RA group, SF-levels of TNF alpha were positively correlated with the degree of bone destruction of the respective joint. No correlation was found between radiographically assessed joint changes and SF-concentrations of other cytokines, enzyme activities, serum CRP, or duration of disease. In the OA-group, none of the examined parameters was associated with the degree of joint destruction.


CONCLUSIONS
Our data may support the assumption of TNF alpha playing an important role in joint destruction in RA. Possible alternative conclusions are discussed.
Neidel
J
J
Department of Orthopaedics, Center for Rheumatology, Bad Bramstedt, Germany.
Schulze
M
M
Lindschau
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000378:metabolism; D001847:Bone Diseases / Q000209:etiology*; D002097:C-Reactive Protein / Q000378:metabolism; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D007719:Knee Joint / Q000378:metabolism*; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism; D012795:Sialoglycoproteins / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D012795:Sialoglycoproteins; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein