title: [Prognostic significance of tryptophan catabolism in adult T-cell leukemia/lymphoma].
abstract: OBJECTIVE
  Indoleamine 2,3-dioxygenase 1 (IDO1: IDO) is an enzyme catabolizing tryptophan (Trp) into the kynurenine (Kyn) pathway, and is an important micro-environmental factor suppressing antitumor immune responses. We investigated the prognostic significance of Trp catabolism in adult T-cell leukemia/lymphoma (ATL).
  
  
  METHODS
  We quantified serum Trp and Kyn in 96 ATL patients, 38 human T-cell lymphotropic virus type-1 asymptomatic carriers (HTLV-1 ACs), and 40 healthy adult volunteers. The relationships between various clinical parameters were analyzed. IDO expression was evaluated in the affected lymph nodes of ATL patients.
  
  
  RESULTS
  Serum Kyn concentrations and Kyn/Trp ratios were significantly higher in HTLV-1 ACs than in healthy controls. Both increased significantly with progression from HTLV-1 AC to ATL. There were no significant differences in serum Trp concentrations between ATL patients, HTLV-1 ACs and controls. IDO was possibly produced by ATL and/or cells in the microenvironment. Multivariate analyses demonstrated a high serum Kyn/Trp ratio and high Kyn level, but not a high Trp level, to be significant independent detrimental prognostic factors in ATL and aggressive variant ATL.
  
  
  CONCLUSIONS
  Quantification of serum Kyn and Trp is prognostically useful for individual ATL patients. Furthermore, ATL is an appropriate disease for testing novel cancer immunotherapies targeting IDO.
authors.affiliation: Department of Hematology & Oncology, Nagoya City University Graduate School of Medical Sciences.
authors.forename: Ayako
authors.initials: A
authors.lastname: Masaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishida
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Maeda
authors.forename: Susumu
authors.initials: S
authors.lastname: Suzuki
authors.forename: Asahi
authors.initials: A
authors.lastname: Ito
authors.forename: Hisashi
authors.initials: H
authors.lastname: Takino
authors.forename: Haruhito
authors.initials: H
authors.lastname: Totani
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Shiori
authors.initials: S
authors.lastname: Kinoshita
authors.forename: Hiroka
authors.initials: H
authors.lastname: Ogura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Narita
authors.forename: Masaki
authors.initials: M
authors.lastname: Ri
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kusumoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Inagaki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Komatsu
authors.forename: Akio
authors.initials: A
authors.lastname: Niimi
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Ueda
authors.forename: Atae
authors.initials: A
authors.lastname: Utsunomiya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Iida
mesh_terms: D000368:Aged; D005260:Female; D015490:HTLV-I Infections / Q000150:complications; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000175:diagnosis* / Q000378:metabolism* / Q000821:virology; D008297:Male; D015999:Multivariate Analysis; D011379:Prognosis; D014364:Tryptophan / Q000378:metabolism
chemical_list: D014364:Tryptophan