Interleukin-18 is a key mediator in dermatomyositis: potential contribution to development of interstitial lung disease.
OBJECTIVE
To determine whether IL-18 is involved in the inflammation of DM and PM.


METHODS
Thirty-three patients with DM were enrolled in this study, including 25 with interstitial lung disease (ILD). In addition, 16 patients with PM were enrolled, including 6 with ILD. All patients were admitted to our hospital as a result of their condition requiring treatment, and clinical laboratory data including serum IL-18 were recorded on admission.


RESULTS
Serum IL-18 was significantly (P < 0.0001) higher in both DM and PM patients than in healthy controls (n = 30). Serum ferritin and IL-18 were significantly (P = 0.003 and 0.0044, respectively) higher in DM than in PM patients. Additionally, ferritin and IL-18 were significantly (P = 0.023 and 0.034, respectively) higher in DM patients with ILD than in DM patients without ILD. Significant positive correlations were found between creatine kinase (CK) and ferritin (r(s) = 0.39, P = 0.024); CK and IL-18 (r(s) = 0.48, P = 0.005); and IL-18 and ferritin (r(s) = 0.54, P = 0.0012) in the DM group as a whole. These findings were different for the DM plus ILD subgroup: significant positive correlations were found between CK and ferritin (r(s) = 0.40, P = 0.047); CK and IL-18 (r(s) = 0.63, P = 0.0008); and IL-18 and ferritin (r(s) = 0.41, P = 0.042).


CONCLUSIONS
Serum IL-18 was strikingly elevated in patients with DM and was associated particularly with disease activity and ILD complication in DM.
Gono
Takahisa
T
Institute of Rheumatology, Tokyo Women's Medical University, Shinjuku-Ku, Tokyo 162-0054, Japan. y-kawa@ior.twmu.ac.jp
Kawaguchi
Yasushi
Y
Sugiura
Tomoko
T
Ichida
Hisae
H
Takagi
Kae
K
Katsumata
Yasuhiro
Y
Hanaoka
Masanori
M
Okamoto
Yuko
Y
Ota
Yuko
Y
Yamanaka
Hisashi
H
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003882:Dermatomyositis / Q000150:complications* / Q000188:drug therapy; D005293:Ferritins / Q000276:immunology*; D006801:Humans; D020382:Interleukin-18 / Q000276:immunology*; D017563:Lung Diseases, Interstitial / Q000188:drug therapy / Q000209:etiology*; D008264:Macrophages / Q000276:immunology; D008875:Middle Aged; D017285:Polymyositis / Q000150:complications* / Q000188:drug therapy; D012189:Retrospective Studies; D013223:Statistics as Topic
D020382:Interleukin-18; D005293:Ferritins