title: Galactomannan Antigen Testing for Diagnosis of Invasive Aspergillosis in Pediatric Hematology Patients.
abstract: OBJECTIVE
  Invasive aspergillosis (IA) can cause significant morbidity and mortality in immunocompromised children. The galactomannan (GM) enzyme immunoassay (EIA) has been shown in adult studies to be a useful adjunct in diagnosing IA. Data on this assay in children are limited by small sample sizes and conflicting results; false-positive assays were a concern in historical studies. We sought to evaluate the GM EIA in a large cohort of children who received intensive chemotherapy and/or hematopoietic stem cell transplant. A focus was placed on evaluating the assay specificity, and the potential of measuring GM antigen in urine.
  
  
  METHODS
  A multicenter prospective observational study in children with anticipated prolonged neutropenia was performed. Serum specimens were collected twice weekly, and urine was collected once weekly during neutropenic periods. Operating characteristics were calculated using the GM EIA optical density index cutoffs of 0.5 and 1.0 for both serum and urine specimens.
  
  
  RESULTS
  At least one serum or urine specimen was tested from 198 patients. Ten patients had one or more repeatedly positive serum specimens, while 37 patients had one or more repeatedly positive urine specimens. The specificity of serum and urine testing was 95% and 80%, respectively. Although the urine test resulted in a higher false positivity rate, it successfully identified the only case of probable IA.
  
  
  CONCLUSIONS
  Data suggest that the serum GM EIA does not provide frequent false-positive results as previously reported. Screening for galactomannan, or a related antigen in urine, needs to be further evaluated as it may be amenable to development of surveillance strategies.
authors.affiliation: Division of Infectious Diseases Center for Pediatric Clinical Effectiveness, The Children's Hospital of Philadelphia, Pennsylvania.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Fisher
authors.affiliation: Division of Infectious Diseases Center for Pediatric Clinical Effectiveness, The Children's Hospital of Philadelphia, Pennsylvania.
authors.forename: Theoklis E
authors.initials: TE
authors.lastname: Zaoutis
authors.affiliation: Seattle Children's Hospital, University of Washington.
authors.forename: Julie R
authors.initials: JR
authors.lastname: Park
authors.affiliation: Seattle Children's Hospital, University of Washington Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Marie
authors.initials: M
authors.lastname: Bleakley
authors.affiliation: Seattle Children's Hospital, University of Washington.
authors.forename: Janet A
authors.initials: JA
authors.lastname: Englund
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Christine
authors.initials: C
authors.lastname: Kane
authors.affiliation: Johns Hopkins School of Medicine Sidney Kimmel Cancer Center, Baltimore, Maryland.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Arceci
authors.affiliation: Departments of Radiation Oncology Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children's Hospital Boston, Massachusetts.
authors.forename: Eva
authors.initials: E
authors.lastname: Guinan
authors.affiliation: Cincinnati Children's Hospital Medical Center University of Cincinnati College of Medicine, Ohio.
authors.forename: Franklin O
authors.initials: FO
authors.lastname: Smith
authors.affiliation: Center for Pediatric Clinical Effectiveness, The Children's Hospital of Philadelphia, Pennsylvania.
authors.forename: Xianqun
authors.initials: X
authors.lastname: Luan
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, Washington Johns Hopkins School of Medicine Sidney Kimmel Cancer Center, Baltimore, Maryland.
authors.forename: Kieren A
authors.initials: KA
authors.lastname: Marr