IL-6 and soluble IL-6 receptors (sIL-6R and sgp130) in human pleural effusions: massive IL-6 production independently of underlying diseases.
IL-6, soluble IL-6 receptor (sIL-6R) and soluble gp130 (sgp130) levels were measured in sera and pleural effusions from 42 patients with metastatic carcinoma, non-Hodgkin's lymphoma, tuberculosis, cardiac failure and miscellaneous diseases. Pleural IL-6 levels measured by ELISA were very high in all patient groups (mean 34.8 +/- 15.3 ng/ml) without significant difference according to diseases. IL-6 was shown to be biologically active in a proliferative assay. Serum IL-6 levels were low (0.049 +/- 0.014 ng/ml) and did not correlate with pleural fluid levels. Pleural IL-6 levels correlated with the number of polymorphonuclear cells in pleural fluid (P < 0.03). Pleural sIL-6R levels (76 +/- 8 ng/ml) were always lower than serum levels (196 +/- 12 ng/ml; P < 0.0001) but correlated with them (P < 0.01). Pleural sIL-6R and albumin levels correlated (P < 0.01), suggesting a transudation of sIL-6R from the serum. Pleural sgp130 levels (10.9 +/- 1.0 ng/ml) were lower than serum levels (24.6 +/- 2.8 ng/ml; P < 0.002). After gel filtration of pleural fluid, the bulk of IL-6 (> 90%) was recovered in a 15,000-30,000 fraction, corresponding to the expected mol. wt of free IL-6. These results suggest a production and a sequestration of IL-6 in the pleural cavity in all studied conditions.
Doré
P
P
URA CNRS 1172, IBMIG, Facultés de Médecine et de Sciences, Poitiers, France.
Lelièvre
E
E
Morel
F
F
Brizard
A
A
Fourcin
M
M
Clemént
C
C
Ingrand
P
P
Daneski
L
L
Gascan
H
H
Wijdenes
J
J
Gombert
J
J
Preud'homme
J L
JL
Lecron
J C
JC
D015703:Antigens, CD / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D050822:Cytokine Receptor gp130; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis* / Q000096:biosynthesis*; D008562:Membrane Glycoproteins / Q000032:analysis*; D010996:Pleural Effusion / Q000276:immunology*; D016066:Pleural Effusion, Malignant / Q000276:immunology*; D018123:Receptors, Interleukin / Q000032:analysis*; D019947:Receptors, Interleukin-6; D015398:Signal Transduction / Q000276:immunology
D015703:Antigens, CD; D015415:Biomarkers; C494199:IL6ST protein, human; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6; D050822:Cytokine Receptor gp130