title: Leukocyte suppression is associated with improved clinical outcomes in children's status after orthotopic heart transplantation.
abstract: BACKGROUND
  Leukocyte suppression is a sequela of immunosuppressive therapy after orthotopic heart transplantation and may result in discontinuation of anti-proliferative agents. Clinical outcomes in this patient population have not been well delineated.
  
  
  METHODS
  This study was a retrospective review of children who underwent orthotopic heart transplantation at our institution from 1986 to 2003. Leukocyte suppression was defined as a white blood cell count <5,000, prompting the withdrawal of anti-proliferative agents. The population was divided into 2 groups, leukosuppressed (LS) and non-leukosuppressed (NLS), and their clinical outcomes were compared.
  
  
  RESULTS
  The study included 109 patients, of which 44 (40%) became leukosuppressed. The 2 groups were similar regarding demographic data and initial management. The LS Group had a significantly decreased incidence of rejection, being 7 times less likely to have recurrent rejection (p = 0.001). The median time to rejection was 0.8 +/- 0.6 years for the NLS Group, whereas the median time to rejection was not yet reached at 17 years for the LS Group. The LS Group also tended toward a decreased incidence of retransplantation or death (p = 0.06). The organ "half-life" in the NLS Group was 7.5 years vs 12.5 years in the LS Group. There was no difference between the 2 groups in regards to other adverse effects of immunosuppression.
  
  
  CONCLUSIONS
  Children who have undergone orthotopic heart transplantation and subsequently become leukosuppressed have a lower incidence of rejection and a tendency toward less organ loss than children who do not become leukosuppressed, without having an increased incidence of adverse side effects.
authors.affiliation: Section of Pediatric Cardiology, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, Texas 77030, USA. jjkim@texaschildrenshospital.org
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Kim
authors.forename: William J
authors.initials: WJ
authors.lastname: Dreyer
authors.forename: E
authors.initials: E
authors.lastname: O'Brian Smith
authors.forename: Jack F
authors.initials: JF
authors.lastname: Price
authors.forename: Sarah
authors.initials: S
authors.lastname: Clunie
authors.forename: V Vasiliki
authors.initials: VV
authors.lastname: Dimas
authors.forename: John L
authors.initials: JL
authors.lastname: Jefferies
authors.forename: Howard
authors.initials: H
authors.lastname: Rosenblatt
authors.forename: Branislav
authors.initials: B
authors.lastname: Radovancevic
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Towbin
authors.forename: Susan W
authors.initials: SW
authors.lastname: Denfield
mesh_terms: D000293:Adolescent; D049109:Cell Proliferation / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D005260:Female; D006084:Graft Rejection / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D016027:Heart Transplantation / Q000276:immunology* / Q000379:methods / Q000473:pathology; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D007223:Infant; D007962:Leukocytes / Q000187:drug effects* / Q000473:pathology* / Q000502:physiology; D007970:Leukopenia / Q000139:chemically induced; D008297:Male; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000276:immunology / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D007166:Immunosuppressive Agents