Comparison of an Aspergillus real-time polymerase chain reaction assay with galactomannan testing of bronchoalvelolar lavage fluid for the diagnosis of invasive pulmonary aspergillosis in lung transplant recipients

Clin Infect Dis. 2011 May;52(10):1218-26. doi: 10.1093/cid/cir185.

Abstract

Background: Early diagnosis and treatment of invasive pulmonary aspergillosis (IPA) improves outcome.

Methods: We compared the performance of publicly available pan-Aspergillus, Aspergillus fumigatus-, and Aspergillus terreus-specific real-time polymerase chain reaction (PCR) assays with the Platelia galactomannan (GM) assay in 150 bronchoalveolar lavage (BAL) samples from lung transplant recipients (16 proven/probable IPA, 26 Aspergillus colonization, 11 non-Aspergillus mold colonization, and 97 negative controls).

Results: The sensitivity and specificity of pan-Aspergillus PCR (optimal quantification cycle [Cq], ≤35.0 by receiver operating characteristic analysis) and GM (≥.5) for diagnosing IPA were 100% (95% confidence interval, 79%-100%) and 88% (79%-92%), and 93% (68%-100%) and 89% (82%-93%), respectively. The sensitivity and specificity of A. fumigatus-specific PCR were 85% (55%-89%) and 96% (91%-98%), respectively. A. terreus-specific PCR was positive for the 1 patient with IPA due to this species; specificity was 99% (148 of 149 samples). Aspergillus PCR identified 1 patient with IPA not diagnosed by GM. For BAL samples associated with Aspergillus colonization, the specificity of GM (92%) was higher than that of pan-Aspergillus PCR (50%; P = .003). Among negative control samples, the specificity of pan-Aspergillus PCR (97%) was higher than that of BAL GM (88%; P = .03). Positive results for both BAL PCR and GM testing improved the specificity to 97% with minimal detriment to sensitivity (93%).

Conclusions: A recently developed pan-Aspergillus PCR assay and GM testing of BAL fluid may facilitate the diagnosis of IPA after lung transplantation. A. fumigatus- and A. terreus-specific real-time PCR assays may be useful in rapidly identifying the most common cause of IPA and a species that is intrinsically resistant to amphotericin B, respectively.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aspergillus fumigatus / chemistry
  • Aspergillus fumigatus / genetics
  • Aspergillus fumigatus / isolation & purification*
  • Bronchoalveolar Lavage Fluid / chemistry
  • Bronchoalveolar Lavage Fluid / microbiology*
  • Clinical Laboratory Techniques / methods*
  • DNA, Fungal / genetics
  • Female
  • Galactose / analogs & derivatives
  • Humans
  • Immunoenzyme Techniques / methods
  • Invasive Pulmonary Aspergillosis / diagnosis*
  • Lung Transplantation
  • Male
  • Mannans / analysis
  • Middle Aged
  • Mycology / methods*
  • Polymerase Chain Reaction / methods*
  • Sensitivity and Specificity
  • Transplantation

Substances

  • DNA, Fungal
  • Mannans
  • galactomannan
  • Galactose