Absence of correlation between interleukin 6 and C-reactive protein blood levels in systemic lupus erythematosus compared with rheumatoid arthritis.
To investigate if the low C-reactive protein (CRP) response frequently observed in systemic lupus erythematosus (SLE) is related to an impaired expression of interleukin 6 (IL-6), considered its main inducer, we studied serum IL-6 and CRP levels in 37 patients with SLE and 22 with rheumatoid arthritis (RA). Results show that in contrast to CRP, IL-6 levels are significantly higher in SLE than in RA. A linear regression analysis shows a positive correlation between levels of these 2 molecules in RA but not in SLE. Similarly, levels of fibrinogen, another acute phase protein mainly induced by IL-6, did not correlate with IL-6 in SLE. Our results suggest an impairment of part of the acute phase response to IL-6 that might play a role in the pathogenesis of SLE.
Gabay
C
C
Division de Rhumatologie, Hôpital Cantonal Universitaire, Geneva, Switzerland.
Roux-Lombard
P
P
de Moerloose
P
P
Dayer
J M
JM
Vischer
T
T
Guerne
P A
PA
D000906:Antibodies / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis*; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D015850:Interleukin-6 / Q000097:blood* / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000097:blood*; D012044:Regression Analysis
D000906:Antibodies; D015850:Interleukin-6; D005340:Fibrinogen; D002097:C-Reactive Protein