Biomarkers for diagnosis and follow-up of invasive candidiasis: A brief review of the ECIL recommendations

The main biomarkers for rapid and non-invasive diagnosis of invasive candidiasis include 1,3-beta-D-glucan (BG), mannan antigen (Mn), anti-mannan antibodies (A-Mn) and various molecular methods. BG, Mn and A-Mn assays are standardized, and data on BG are the most extensive. For haematology and oncology population, its performance is characterised by suboptimal sensitivity but excellent specificity. For these populations, the experts from the third European Conference on Infections in Leukemia (ECIL-3) recommended BG for detection of invasive fungal infections with grading BII, and combined Mn/A-Mn detection for the diagnosis of candidemia and hepatosplenic candidiasis, with grading CII and BIII, respectively. While very promising, PCR lacks standardization and thus could not be formally recommended. There is limited and contradictory data on the performance of BG for the monitoring of outcome in patients with invasive candidiasis, although a trend of decline or increase of BG levels was found to be associated with, respectively, a successful response or failure.