Increased interleukin-18 expression in bone marrow of a patient with systemic juvenile idiopathic arthritis and unrecognized macrophage-activation syndrome.
The aberrant induction of proinflammatory cytokines is considered to be crucial in the pathogenesis of systemic juvenile idiopathic arthritis and adult-onset Still's disease. Interleukin-18 (IL-18) in particular has been reported to be a candidate for the key cytokine in both diseases; however, the origin of IL-18 is unclear. To clarify the origin, we investigated specimens from various organs obtained during autopsy of a child with systemic JIA and macrophage activation syndrome, using immunohistochemical staining. Our results showed a high number of cells expressing IL-18 in the bone marrow but not in the other organs. This finding suggests that bone marrow is the origin of increased serum IL-18 and raises the possibility that other proinflammatory cytokines are also induced by IL-18 in bone marrow in this disease. Bone marrow may be an essential organ in the pathogenesis of systemic JIA.
Maeno
Nobuaki
N
Department of Infection and Immunity, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima, Japan. maeno@m3.kufm.kagoshima-u.ac.jp
Takei
Syuji
S
Imanaka
Hiroyuki
H
Yamamoto
Kimie
K
Kuriwaki
Kazumi
K
Kawano
Yoshifumi
Y
Oda
Hiroshi
H
D001171:Arthritis, Juvenile / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D001853:Bone Marrow / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D020382:Interleukin-18 / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology / Q000473:pathology*
D020382:Interleukin-18