The acute phase nature of interleukin 6: studies in Kawasaki disease and other febrile illnesses.
Interleukin 6 (IL-6) has manifold biological functions involved in the immune or inflammatory responses of the host to various stimuli. Here we asked whether IL-6 might be responsible for manifestations of Kawasaki disease (KD), such as immunoglobulin hypersecretion, lymphocyte activation and systemic vasculitis. IL-6 activity in the serum was determined by a sensitive colorimetric assay using an IL-6-dependent murine hybridoma clone. Usually sera from healthy or afebrile donors contained only negligible levels of IL-6 activity below the detection threshold of the assay. Importantly it was found that serum IL-6 was markedly elevated in all patients with acute KD. Serum levels of IL-6 activity gradually diminished during the course of the disease and reached undetectable or lower levels at the convalescent phase. However, such elevated levels of serum IL-6 activity were also observed in the majority of other febrile diseases, such as bacterial or viral infections, indicating that the appearance of IL-6 in the serum could generally occur in febrile or inflammatory disease conditions. Serum IL-6 activity correlated with serum concentrations of some acute phase proteins (APP), such as C-reactive protein, haptoglobin and alpha 1-acid glycoprotein, implying its role for modulating induction of APP in vivo. IL-6 is well known to be secreted by a variety of cell types. Further studies, including immunohistochemical analysis using anti-IL-6 antibody, will be necessary to examine whether the source of serum IL-6 in KD might be different from that seen in other diseases.
Ueno
Y
Y
Department of Pediatrics, School of Medicine, Kanazawa University, Japan.
Takano
N
N
Kanegane
H
H
Yokoi
T
T
Yachie
A
A
Miyawaki
T
T
Taniguchi
N
N
D000209:Acute-Phase Proteins / Q000097:blood; D000210:Acute-Phase Reaction / Q000209:etiology*; D000328:Adult; D002675:Child, Preschool; D005334:Fever / Q000097:blood / Q000209:etiology*; D006801:Humans; D007223:Infant; D007249:Inflammation / Q000209:etiology*; D015850:Interleukin-6; D007378:Interleukins / Q000096:biosynthesis / Q000097:blood / Q000502:physiology*; D009080:Mucocutaneous Lymph Node Syndrome / Q000097:blood / Q000209:etiology*
D000209:Acute-Phase Proteins; D015850:Interleukin-6; D007378:Interleukins