Elevated interleukin-18 levels in bronchoalveolar lavage fluid of patients with eosinophilic pneumonia.
BACKGROUND
Interleukin (IL)-18 can induce Th2 cytokine production particularly in collaboration with IL-2. Accumulation of Th2 cells and increased levels of Th2 cytokines are found in bronchoalveolar lavage fluid (BALF) from patients with eosinophilic pneumonia (EP). To evaluate the role of IL-18 in the pathogenesis of EP, we measured the concentration of IL-2, IL-12, IL-18, and Th2 cytokines in BALF from patients with EP.


METHODS
The concentrations of interferon (IFN)-gamma, IL-2, IL-5, IL-10, IL-12, IL-13, and IL-18 in BALF were measured in patients with idiopathic acute eosinophilic pneumonia (AEP), with idiopathic chronic eosinophilic pneumonia (CEP), with sarcoidosis and healthy volunteers (HV).


RESULTS
The BALF concentrations of Th2 cytokines, IL-5, IL-10, and IL-13, were higher in patients with EP than in sarcoidosis and control. The IL-2 level in BALF was higher in EP than in sarcoidosis and control. The IL-18 and IL-12 (p40 + p70) levels were higher in patients with EP than sarcoidosis, while the level of IL-12 (p70) was below the detection limit in patients with EP. There was a significant correlation between IL-2 level and both IL-5 and IL-13 in BALF of patients with EP.


CONCLUSIONS
Our findings suggest that IL-18 may contribute to Th2 cytokine-dominant responses in patients with EP in collaboration with IL-2.
Katoh
S
S
Third Department of Internal Medicine, Miyazaki Medical College, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
Matsumoto
N
N
Matsumoto
K
K
Fukushima
K
K
Matsukura
S
S
D000328:Adult; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000032:analysis; D018664:Interleukin-12 / Q000032:analysis; D018793:Interleukin-13 / Q000032:analysis; D020382:Interleukin-18 / Q000032:analysis*; D007376:Interleukin-2 / Q000032:analysis; D015848:Interleukin-5 / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011657:Pulmonary Eosinophilia / Q000209:etiology / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology
D018793:Interleukin-13; D020382:Interleukin-18; D007376:Interleukin-2; D015848:Interleukin-5; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma