title: Serum cytokines in patients with Legionella pneumonia: relative predominance of Th1-type cytokines.
abstract: Serum samples from 14 patients with Legionella pneumonia were examined for the presence of cytokines. In spite of high levels of serum C-reactive protein in all patients during the acute phase in only four cases (one involving interleukin-1beta [IL-1beta], three involving IL-6, and none involving tumor necrosis factor alpha) was the concentration of cytokines more than 100 pg/ml. Th2 cytokines IL-4 and IL-10 were detected in only one patient each. In contrast, significant increases of serum gamma interferon (IFN-gamma) and IL-12 levels were observed during the acute phase in 6 and 11 cases, respectively. Interestingly, although serum IFN-gamma levels diminished thereafter, in seven cases IL-12 levels remained high or increased further during the convalescent phase. In an additional 22 cases clinically suspected to be but not diagnosed as Legionella pneumonia, increases of serum IL-12 levels were observed in 16 cases, whereas the remaining 6 cases showed no detectable IL-12. Our results demonstrate the relative predominance of Th1 cytokine production in Legionella pneumonia. Although the role and significance of prolonged increases in IL-12 levels in Legionella disease are unknown, our results should prompt further investigation of the host immune response in terms of Th1 and Th2 balance in legionellosis.
authors.affiliation: Department of Microbiology, Toho University School of Medicine, Tokyo, Japan. kazu@sirius.med.toho-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Tateda
authors.forename: T
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Y
authors.initials: Y
authors.lastname: Ishii
authors.forename: N
authors.initials: N
authors.lastname: Furuya
authors.forename: A
authors.initials: A
authors.lastname: Ohno
authors.forename: S
authors.initials: S
authors.lastname: Miyazaki
authors.forename: K
authors.initials: K
authors.lastname: Yamaguchi
mesh_terms: D016207:Cytokines / Q000097:blood*; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D018664:Interleukin-12 / Q000097:blood; D007875:Legionella / Q000302:isolation & purification; D016952:Legionella pneumophila / Q000302:isolation & purification; D007876:Legionellosis / Q000175:diagnosis / Q000276:immunology*; D007877:Legionnaires' Disease / Q000276:immunology*; D018410:Pneumonia, Bacterial / Q000175:diagnosis / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*
chemical_list: D016207:Cytokines; D018664:Interleukin-12; D007371:Interferon-gamma