Combining Aspergillus mitochondrial and ribosomal QPCR, in addition to galactomannan assay, for early diagnosis of invasive aspergillosis in hematology patients

Abstract

The combination of two quantitative Aspergillus PCR assays, targeting a mitochondrial and a ribosomal target (AfQPCR), has proved effective for diagnosing invasive aspergillosis (IA) in hematology patients with risk factors and a positive galactomannan antigen (GM). The aim of the present study was to assess the performance of systematic AfQPCR for IA screening in at risk patients in a hematology intensive care unit (ICU). The study was performed in the hematology ICU at Besançon University Hospital from March 2012 to December 2013. GM detection (Platelia Aspergillus, Biorad, France) and AfQPCR were performed on the same serum sample, twice a week, in all patients with risk factors for IA. Risk factors and clinical, radiological, and biological data were prospectively recorded using the information sheet from the French network for the surveillance of Invasive Fungal Infection. Thirty-two patients were diagnosed with proven, probable, or possible IA according to the 2008 EORTC/MSG criteria. Sixteen patients had a positive AfQPCR: 9/16 had a positive GM at the same time (GM index >0.5), 4/16 had a positive GM before the AfQPCR and 3/16 had a negative GM at the time of the positive AfQPCR. Screening at risk patients using both AfQPCR and GM on the same serum sample is very feasible in a routine clinical setting. Our results confirm the usefulness of combining biomarkers for an early IA diagnosis.

Keywords: QPCR; galactomannan; invasive aspergillosis.