Mori Y, Nagasaki Y, Kamezaki K et al. Am J Hematol 2010;85:449–51.
The value of galactomannan (GM) antigen detection in the diagnosis of invasive aspergillosis (IA) was examined retrospectively in 124 patients with hematological disorders in this study. In this population, although 21 patients (16.9%) had at least two consecutive positive GM tests, 14 patients were found to have false-positive results. Of these 14 patients with false-positive results, 11 had a diagnosis of multiple myeloma. Multivariate analysis revealed that immunoglobulin G myeloma was the only independent patient risk factor of false-positivity.
Detection of galactomannan (GM) antigen among patients at high risk for invasive aspergillosis (IA) has become an important means by which to facilitate early diagnosis of IA. Unfortunately, GM assays are prone to false-positive results, particularly in pediatric patients [1], patients with graft-versus-host disease [2], those taking dietary GM [3], or those receiving fungus-derived antibiotics [4]. This article highlights false-positive GM antigen test results in patients with hematological malignancies.