The role of galactomannan test results in the diagnosis of pediatric invasive aspergillosis

Background Invasive aspergillosis (IA) is an important cause of morbidity and mortality in immunosuppressed children. Early detection of the infection can improve prognosis in this patient population. Objectives To investigate the utility of Aspergillus galactomannan antigen assay (GM-EIA) as a diagnostic tool for IA in at-risk paediatric patients. Patients/Methods For the study, 659 GM-EIA results from 59 patients diagnosed with IA and 3368 GM-EIA results from 351 subjects without evidence for IA (controls) were reviewed retrospectively. Three cut-off values (i.e. >= 0.5, >= 1, >= 1.5) were specified to determine GM-EIA positivity. Results The median age was 6.3 years for boys and 14.5 years for girls. There was a significant difference between the girls and boys in terms of age (p < 0.01). For proven/probable/possible IA patients, sensitivity of 67.8% and specificity of 59.8% were detected when the >= 0.5 cut-off value was used for GM-EIA-positivity. The specificity increased to 80% at the cut-off of >= 1 and to 88% at the cut-off of >= 1.5. False positivity rates were 9.14, 3, and 1.45% at the >= 0.5, >= 1 and >= 1.5 cut-offs respectively. In the proven/probable IA group, sensitivity and negative predictive values were 86.9 and 97.2% at the >= 0.5 cut-off, 85.7 and 97.9%, at the >= 1 cut-off and 84.2 and 98.1% at >= 1.5 cut-off respectively. The positive likelihood ratio was 7.57 and the odds ratio was 42.67 at >= 1.5 cut-off. Conclusion The GM-EIA may be used for both screening and diagnostic purposes in paediatric patients using a cut-off value of >= 1.5 for GM-EIA positivity.