Galactomannan enzyme immunoassay and quantitative Real Time PCR as tools to evaluate the exposure and response in a rat model of aspergillosis after posaconazole prophylaxis

Enferm Infecc Microbiol Clin. 2016 Nov;34(9):571-576. doi: 10.1016/j.eimc.2015.11.008. Epub 2016 Jan 21.

Abstract

Introduction: A steroid-immunosuppressed rat model of invasive pulmonary aspergillosis was use to examine the usefulness of galactomannan enzyme immunoassay (GM) and quantitative real time PCR (RT-PCR) in evaluating the association between response and exposure after a high dose of prophylactic posaconazole.

Methods: Two different strains of Aspergillus fumigatus with different in vitro posaconazole susceptibility were used.

Results: Serum concentrations demonstrated similar posaconazole exposure for all treated animals. However, response to posaconazole relied on the in vitro susceptibility of the infecting strain. After prophylaxis, galactomannan index and fungal burden only decreased in those animals infected with the most susceptible strain.

Conclusion: This study demonstrated that both biomarkers may be useful tools for predicting efficacy of antifungal compounds in prophylaxis.

Keywords: Antifungal prophylaxis; Carga fúngica; Fungal burden; Galactomanano; Galactomannan; Modelo de rata inmunodeprimida con esteroides; Profilaxis antifúngica; Steroid-immunosuppressed rat model.

MeSH terms

  • Animals
  • Antifungal Agents / blood
  • Antifungal Agents / therapeutic use*
  • Biomarkers / blood
  • Galactose / analogs & derivatives
  • Immunoenzyme Techniques
  • Mannans / blood*
  • Pulmonary Aspergillosis / blood
  • Pulmonary Aspergillosis / drug therapy*
  • Rats
  • Real-Time Polymerase Chain Reaction / methods*
  • Triazoles / blood
  • Triazoles / therapeutic use*

Substances

  • Antifungal Agents
  • Biomarkers
  • Mannans
  • Triazoles
  • galactomannan
  • posaconazole
  • Galactose