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

Rev Soc Bras Med Trop. 2018 May-Jun;51(3):387-389. doi: 10.1590/0037-8682-0317-2017.

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.

MeSH terms

  • Aspergillus fumigatus / isolation & purification*
  • Enzyme-Linked Immunosorbent Assay / adverse effects*
  • Enzyme-Linked Immunosorbent Assay / methods
  • False Positive Reactions*
  • Galactose / analogs & derivatives
  • Humans
  • Mannans*
  • Spores, Fungal*

Substances

  • Mannans
  • galactomannan
  • Galactose