Clinical utility of a panfungal polymerase chain reaction assay for invasive fungal diseases in patients with haematologic disorders

Abstract

Objectives: Invasive fungal diseases (IFDs) are life-threatening events in patients with haematologic disorders, and the spectrum of the aetiological pathogens continues to expand. This study aimed to evaluate the clinical utility of a panfungal polymerase chain reaction (PCR) assay for the management of IFDs in such patients.

Methods: We prospectively analysed 273 consecutive blood samples from 64 risk episodes in 51 patients with haematologic disorders at high risk for IFD who were treated at our hospital between April 2007 and October 2010.

Results: PCR-positive results were obtained in 18 of 64 risk episodes (35.3%). IFD was documented in 14 episodes (21.9%, 9 probable IFDs and 5 possible IFDs) according to the revised criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group. PCR was positive in all of these 14 episodes, and in 4 of the 50 episodes with no IFD category. Sensitivity, specificity, positive predictive value, and negative predictive value of our assay were 100%, 92%, 78% and 100% respectively. A considerable number of fungi (44.4%) that are less common than Aspergillus and Candida species were positive by PCR. Molecular diagnoses of Cunninghamella species, Aspergillus ustus, Fusarium species, Scedosporium apiospermum, Rhodotorula species and Rhizopus species were beneficial in selecting suitable treatments.

Conclusions: Our panfungal PCR approach allows for the highly sensitive and specific detection and identification of a wide spectrum of fungal pathogens, which provides indispensable information for managing IFDs, especially refractory or breakthrough IFDs during antifungal therapy in high-risk patients with haematologic disorders.