Use of 1,3-beta-d-glucan concentration in peritoneal fluid for the diagnosis of intra-abdominal candidiasis in critically ill patients

Intra-abdominal candidiasis (IAC) is frequent and associated with high mortality in intensive care unit (ICU) patients. Antifungal treatments may be overused due to a lack of diagnostic tools to rule out IAC. Serum 1,3-beta-d-glucan (BDG) concentrations are used to diagnose Candida infections, its concentration in peritoneal fluid (PF) may help to confirm or invalidate the diagnosis of IAC. We performed a non-interventional, prospective, multicenter study at the Hospices Civils de Lyon, France, in seven ICUs located in three different hospitals from December 2017 to June 2018. IAC was defined as the isolation of Candida in a sample collected from the intra-abdominal cavity under sterile conditions in patients displaying clinical evidence of intra-abdominal infection (IAI).Among the 113 included patients, 135 PF samples corresponding to 135 IAI episodes were collected and BDG concentrations were assessed. IAC accounted for 28 (20.7%) of the IAIs. Antifungals were administered empirically to 70 (61.9%) patients; among them, 23 (32.9%) had an IAC. The median [interquartile range] BDG value was significantly higher in IAC (8100 [3000; 15 000] pg/ml) than in non-IAC samples (1961 [332; 10 650] pg/ml). BDG concentrations were higher in PF with Fecaloid aspect and in case of positive bacterial culture. For a BDG threshold of 125 pg/ml, the negative predictive value to assess IAC was 100%. In conclusion, low BDG-PF concentrations could be used to rule out IAC.