Aspergillus galactomannan antigen assay and invasive aspergillosis in pediatric cancer patients and hematopoietic stem cell transplant recipients

Pediatr Blood Cancer. 2013 Feb;60(2):316-22. doi: 10.1002/pbc.24363. Epub 2012 Oct 5.

Abstract

Background: Invasive aspergillosis (IA) is a major cause of morbidity and mortality in immunocompromised children. We investigated the usefulness of an Aspergillus galactomannan (GM) antigen assay as a diagnostic tool for IA in pediatric cancer patients and hematopoietic cell transplantation (HCT) recipients.

Procedure: The GM antigen assay results were analyzed in 749 blood samples from 99 patients. A GM index (GMI) greater than or equal to 0.5 on at least two separate occasions was considered positive. A review of the clinical data was performed for subjects with proven or probable IA.

Results: Twenty-one of 23 patients with proven or probable IA had positive GM antigen test results (91.3% sensitivity, 95% CI 71.9-98.9; 81.7% specificity, 95% CI 69.6-90.5; P < 0.0001). The false-positive rate was 18.3%. Being younger than 3 years of age, having a solid tumor, and receiving HCT within 4 weeks of the test were statistically significant factors for causing false-positive results (P < 0.05). Among the 23 patients with IA (six proven, 17 probable), 16 (69.6%) had hematological malignancies, five (22.7%) had solid tumors, and two (8.7%) had primary immunodeficiency. Nineteen patients (82.6%) received HCT. The most common clinical site of IA was the lungs (91.3%), and consolidation was the most frequent finding in chest CT scans (36.8%). The mortality at 12 weeks was 43.5%.

Conclusions: Having a positive GM assay at least twice is useful in diagnosing IA in pediatric patients with cancer and HCT recipients.

MeSH terms

  • Adolescent
  • Antigens, Fungal / analysis*
  • Aspergillosis / diagnosis*
  • Child
  • Child, Preschool
  • False Positive Reactions
  • Female
  • Galactose / analogs & derivatives
  • Hematologic Neoplasms / complications*
  • Hematologic Neoplasms / microbiology
  • Hematopoietic Stem Cell Transplantation / adverse effects*
  • Humans
  • Immunoenzyme Techniques / methods*
  • Infant
  • Male
  • Mannans / analysis*
  • Sensitivity and Specificity

Substances

  • Antigens, Fungal
  • Mannans
  • galactomannan
  • Galactose