Interleukin-6 in relation to other proinflammatory cytokines, chemotactic activity and neutrophil activation in rheumatoid synovial fluid.
OBJECTIVE
To evaluate the relation between synovial fluid (SF) concentrations of interleukin-6 (IL-6) and other mediators of inflammation which are responsible for joint degradation in rheumatoid arthritis (RA).


METHODS
We measured IL-6, IL-1 beta, tumour necrosis factor alpha (TNF alpha), granulocyte macrophage colony stimulating factor, IL-8, and polymorphonuclear leucocyte (PMNL) chemotaxis and degranulation in SF from patients with RA (n = 30) in the early phase of the disease.


RESULTS
In a cross-sectional study IL-6 concentrations correlated with those of IL-1 beta, IL-8 and with PMNL activation as reflected by lactoferrin concentrations. In a longitudinal study, changes in IL-6 concentrations correlated with changes in TNF alpha, IL-8 and lactoferrin concentrations.


CONCLUSIONS
IL-6 in SF appears to reflect the local proinflammatory, potentially erosive activity in RA. This supports the use of acute phase proteins, which are mainly induced by IL-6, as variables to monitor the course of RA.
van Leeuwen
M A
MA
Department of Rheumatology, University Hospital Groningen, The Netherlands.
Westra
J
J
Limburg
P C
PC
van Riel
P L
PL
van Rijswijk
M H
MH
D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D003430:Cross-Sectional Studies; D005500:Follow-Up Studies; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis*; D016209:Interleukin-8 / Q000032:analysis; D007781:Lactoferrin / Q000032:analysis; D018375:Neutrophil Activation / Q000502:physiology*; D011446:Prospective Studies; D013582:Synovial Fluid / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D007781:Lactoferrin