Utility of the serum galactomannan assay for the diagnosis of invasive aspergillosis in children with acute lymphoblastic leukemia.

Objectives: Invasive aspergillosis (IA) is an important cause of mortality and morbidity in children with hematological malignancies. The monitoring of serum galactomannan (GM) antigen is considered useful in the diagnosis of IA . The aim of this study was to determine the utility of serum GM monitoring in the early diagnosis of IA and the role of positive antigenemia in the management of children with acute lymphoblastic leukemia (ALL).

Methods: The cases of 141 children who were being treated for ALL in the Division of Pediatric Hematology of the Medical School of Ege University between January 2006 and February 2015 were reviewed retrospectively. Cases of proven and probable IA were defined according to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria.

Results: The incidence of proven and probable IA was 3.5% (5/141). The incidence of positive GM antigenemia among 3264 serum samples was 5.5% (n=179). Of the cases detected, 21.7% were true-positive, 52.1% were false-positive, and the remaining 26.1% were classified as 'undetermined.' An increase in the incidence of true-positive tests and induction of antifungal therapy was determined through multiple consecutive positive tests.

Conclusions: GM may be detected in the serum before the clinical signs of IA appear, but its sensitivity and specificity are variable. False-positivity is a significant disadvantage, and consecutive positive GM must be taken into account in the case of clinical and imaging findings that are relevant to IA.