[Interactions and false positive results of galactomannan antigen detection for diagnosis of invasive aspergillosis]

Abstract

Invasive aspergillosis (IA) is a leading cause of morbidity and mortality in immunocompromised hosts, with a survival rate lower than 50%. Although proven diagnosis of IA requires histopathological evidence of deep-tissue invasion, eventually supported by microbiological cultures, critical conditions of patients often hamper invasive diagnostic procedures, and many IA cases are not diagnosed during life. Detection of circulating galactomannan antigens is a non-invasive method widely used to support the diagnosis of IA. However, results of test performance have been variable and, in particular, the method shows specificity problems due to cross reactions and false positive results caused by other microorganisms, foods, antibiotics, graft versus host disease and particular physiological conditions of premature infants. It appears therefore mandatory to know exactly all these possible interactions, in order to properly evaluate GM test results and correctly apply them to the diagnosis of IA and to clinical practice.