title: Absence of biallelic TCRγ deletion predicts induction failure and poorer outcomes in childhood T-cell acute lymphoblastic leukemia.
abstract: BACKGROUND
  The absence of biallelic TCRγ deletion (ABD) is a characteristic of early thymocyte precursors before V(D)J recombination. The ABD was reported to predict early treatment failure in T-cell acute lymphoblastic leukemia (ALL). This study aimed to investigate its prognostic value in Taiwanese patients with T-cell ALL.
  
  
  METHODS
  Forty-five children with T-cell ALL were enrolled from six medical centers in Taiwan. Quantitative DNA polymerase chain reaction (Q-PCR) was performed to check the status of TCRγ deletion. The threshold for homozygous deletions by Q-PCR was defined as a fold-change <0.35.
  
  
  RESULTS
  ABD was found in 20 patients [20:45] who had higher incidences of induction failure than those without ABD (P = 0.03; hazard ratio [HR] = 8.13; 95% confidence interval [95% CI] = 1.23-53.77) after multivariate regression analysis. Patents with ABD also had inferior EFS and OS (P = 0.071 and 0.0196, respectively). Multivariate Cox analysis indicated that the association between ABD and overall survival was independent of age and leukocyte count on presentation (P = 0.036; HR = 4.25; 95% CI = 1.10-16.42).
  
  
  CONCLUSIONS
  The absence of TCRγ deletion is a predictor of a poor response to induction chemotherapy for pediatric patients with T-cell ALL in Taiwan. Providing patients with T-cell ALL and ABD with alternative regimens may be worthwhile to test in future clinical trials.
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yung-Li
authors.initials: YL
authors.lastname: Yang
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Hsiao
authors.forename: Hsuan-Yu
authors.initials: HY
authors.lastname: Chen
authors.forename: Kai-Hsin
authors.initials: KH
authors.lastname: Lin
authors.forename: Shiann-Tarng
authors.initials: ST
authors.lastname: Jou
authors.forename: Jiann-Shiuh
authors.initials: JS
authors.lastname: Chen
authors.forename: Te-Kau
authors.initials: TK
authors.lastname: Chang
authors.forename: Jiunn-Ming
authors.initials: JM
authors.lastname: Sheen
authors.forename: Sung-Liang
authors.initials: SL
authors.lastname: Yu
authors.forename: Meng-Yao
authors.initials: MY
authors.lastname: Lu
authors.forename: Chao-Neng
authors.initials: CN
authors.lastname: Cheng
authors.forename: Kang-Hsi
authors.initials: KH
authors.lastname: Wu
authors.forename: Shih-Chung
authors.initials: SC
authors.lastname: Wang
authors.forename: Jiaan-Der
authors.initials: JD
authors.lastname: Wang
authors.forename: Hsiu-Hao
authors.initials: HH
authors.lastname: Chang
authors.forename: Shu-Rung
authors.initials: SR
authors.lastname: Lin
authors.forename: Shu-Wha
authors.initials: SW
authors.lastname: Lin
authors.forename: Dong-Tsamn
authors.initials: DT
authors.lastname: Lin
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D018572:Disease-Free Survival; D017353:Gene Deletion; D019675:Genes, T-Cell Receptor gamma / Q000235:genetics*; D006801:Humans; D016130:Immunophenotyping; D060828:Induction Chemotherapy; D053208:Kaplan-Meier Estimate; D016133:Polymerase Chain Reaction; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000235:genetics* / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D060888:Real-Time Polymerase Chain Reaction; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta