Interleukin-10 secretion by alveolar macrophages and monocytes in sarcoidosis.
BACKGROUND
Alveolitis and the production of proinflammatory cytokines are known features of sarcoidosis. Because of the usually spontaneous resolution of alveolitis despite local secretion of mediators causing inflammation and granuloma formation, we hypothesized that downmodulating mechanisms such as anti-inflammatory cytokines might be involved in this process.


OBJECTIVE
Investigation of the secretion of the macrophage deactivating cytokines interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta) by alveolar macrophages in untreated sarcoidosis of the lung.


METHODS
Fourteen consecutive and untreated patients with pulmonary sarcoidosis and 18 volunteers underwent bronchoscopy. Alveolar macrophages (AM) were obtained by bronchoalveolar lavage and the secretion of IL-10 and TGF-beta was studied.


RESULTS
Spontaneous IL-10 production by AM was found in 6 of 14 patients and in 2 of 18 controls. The IL-10 level of lipopolysaccharide-stimulated AM was significantly higher in patients. Monocytes secreted significantly more IL-10 than AM, but there was no difference between sarcoid and control monocytes. No difference was found in the secretion of TGF-beta between patients and controls.


CONCLUSIONS
Increased local secretion of IL-10 - but not TGF-beta - may represent a downmodulating mechanism involved in the spontaneous resolution of alveolitis in sarcoidosis.
Bingisser
R
R
Department of Internal Medicine, Division of Pneumology, University Hospital, Zürich, Switzerland.
Speich
R
R
Zollinger
A
A
Russi
E
E
Frei
K
K
D000328:Adult; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D001999:Bronchoscopy; D015536:Down-Regulation; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000032:analysis / Q000378:metabolism*; D016676:Macrophages, Alveolar / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000737:chemistry / Q000378:metabolism*; D011336:Probability; D012016:Reference Values; D017565:Sarcoidosis, Pulmonary / Q000175:diagnosis / Q000276:immunology*; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000378:metabolism*
D016212:Transforming Growth Factor beta; D016753:Interleukin-10