title: Clinical impact and predisposing factors of delayed-onset neutropenia after autologous hematopoietic stem-cell transplantation for B-cell non-Hodgkin lymphoma: association with an incremental risk of infectious events.
abstract: BACKGROUND
  Clinical significance of delayed-onset neutropenia (DON) after autologous hematopoietic stem-cell transplantation (ASCT) has not been well described. We conducted a retrospective cohort study to examine risk factors and clinical impact of DON.
  
  
  METHODS
  Subjects were consecutive 108 patients with B-cell lymphoma receiving ASCT. We defined DON as absolute neutrophil counts <1.0 x 10(9)/l at any point from 30 days onward after ASCT without apparent causes of neutropenia. Documented infectious events were reviewed from 1 to 18 months after ASCT.
  
  
  RESULTS
  Fifty-two percent of patients received rituximab. Cumulative incidence of DON was 50% at 1 year. Rituximab usage was identified as an independent risk factor of DON. A total of 117 infectious events were documented, of which 24 events occurred during DON period. Cumulative incidence of total infectious events was 75% and 42% in the groups with and without DON, respectively (P = 0.001). Varicella-zoster virus (P = 0.033) and upper respiratory infection (P = 0.016) were frequent in the patients experiencing DON. In a multivariable analysis, DON remained a significant factor for total infectious events and upper respiratory infection.
  
  
  CONCLUSIONS
  Rituximab usage is an independent risk factor of DON. DON correlates with increased occurrence of infectious events. Careful follow-up would be needed after the onset of DON.
authors.affiliation: Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital; Division of Molecular Medicine.
authors.forename: H
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital. Electronic address: kyamamoto@aichi-cc.jp.
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, Nagoya, Aichi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsuo
authors.affiliation: Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital.
authors.forename: Y
authors.initials: Y
authors.lastname: Oki
authors.affiliation: Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital.
authors.forename: H
authors.initials: H
authors.lastname: Taji
authors.affiliation: Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital.
authors.forename: Y
authors.initials: Y
authors.lastname: Kuwatsuka
authors.affiliation: Division of Molecular Medicine.
authors.forename: M
authors.initials: M
authors.lastname: Seto
authors.affiliation: Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital.
authors.forename: Y
authors.initials: Y
authors.lastname: Kagami
authors.affiliation: Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital.
authors.forename: Y
authors.initials: Y
authors.lastname: Morishima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D015994:Incidence; D007239:Infections / Q000150:complications*; D016393:Lymphoma, B-Cell / Q000150:complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009503:Neutropenia / Q000150:complications*; D012307:Risk Factors; D055815:Young Adult