Prevalence and Clinical Characteristics of False-Positive Aspergillus Galactomannan Test in Healthy Subjects and Patients with Hematologic Malignancies

• Published in: Blood 2018-11, Vol.132 (Supplement 1), p.2408-2408
• Main Authors: Abe, Yoshiaki, Narita, Kentaro, Kobayashi, Hiroki, Kitadate, Akihiro, Takeuchi, Masami, Matsue, Kosei
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2018-99-110939

▪ Background: Monitoring of the Aspergillus galactomannan (GM) antigen is an useful tool for early diagnosis of aspergillosis, especially in patients with hematologic malignancies. However, one of the major limitations of this assay is false-positivity, which has been described in pediatric patients, patients with graft-versus-host disease, and those taking dietary GM or certain antibiotics. Only a few studies have shown high incidence of false-positive GM test results in patients with multiple myeloma (MM). Here we investigated the prevalence of false-positive GM test results in healthy subjects and in patients with hematologic malignancies. Methods: First, we analyzed the prevalence and distribution of false-positive GM test results in healthy subjects. Next, we retrospectively analyzed the prevalence and clinical characteristics of false-positive GM test results in consecutive patients with symptomatic MM diagnosed between 2006 and 2018 at Kameda Medical Center, Kamogawa, Japan, and compared these findings with those of our historical cohort of patients with hematologic malignancies other than plasma cell disorders (consecutive patients with non-Hodgkin lymphoma [NHL] and myelodysplastic syndrome [MDS]). Patients with clinical and/or imaging findings consistent with aspergillosis (e.g. sinopulmonary infection) were excluded from the analysis. Serum GM was measured using the double-sandwich enzyme-linked immunosorbent assay (Platelia, Bio-Rad, France) in all subjects before any use of antibiotics or anticancer agents. Serum GM test results were considered positive for optical index value of ≥0.5 in duplicate tests. Results: We enrolled 572 healthy subjects. The median age was 46 years (interquartile range [IQR]: 30-55 years), and 267 (46.7%) were men. We found a positive correlation between the GM antigen levels and age; GM antigen levels tended to be higher in older patients (Figure 1A), and the patients with false-positive GM results were significantly older than those without (median: 54 and 43 years, respectively; P