Can Aspergillus fumigatus conidia cause false-positive results in the galactomannan enzyme immunoassay test?

• Published in: Revista da Sociedade Brasileira de Medicina Tropical
• Main Authors: Ângela Leitzke Cabana, Josiara Furtado Mendes, Gabriel Baracy Klafke, Tchana Martinez Brandolt, Aryse Martins Melo, Mário Carlos Araújo Meireles, Melissa Orzechowski Xavier
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sociedade Brasileira de Medicina Tropical (SBMT)
• Subjects: Invasive aspergillosis; Diagnosis; Platelia® Aspergillus EIA; Galactomannan; Air quality; Arctic medicine. Tropical medicine; RC955-962; Arctic; Eia
• Online Access: https://doi.org/10.1590/0037-8682-0317-2017; https://doaj.org/article/810b56e06cc04dad96e8b183cbf63820

Abstract INTRODUCTION: Several factors can cause false-positive results in the galactomannan (GM) test; however, others remain unknown. Presently, the impact of airborne contamination by Aspergillus conidia during enzyme-linked immunosorbent assay (ELISA) remains uninvestigated. METHODS: We studied 12 A. fumigatus isolates. Fungal conidia were serially diluted and tested for GM detection using the Platelia® Aspergillus enzyme immunoassay (EIA). RESULTS: The conidia concentration required for an EIA-positive result was 4.8 × 103 (median). CONCLUSIONS: This is the first study to evaluate the impact of environmental contamination on the Platelia® Aspergillus EIA assay. Only massive contamination can interfere with GM optical readings, suggesting that environmental contamination does not cause false-positive test results.