Titel: Diagnostic performance of serum (1→3)-β-D-glucan and mannan for early diagnosis and follow-up in patients with candidemia
Art: Abstractautor
Session: Workshop 05
Diagnostic Stewardship - "Meet the needs of your partners!" (FG DKM, FG QD)

Referent: Jürgen Held (Erlangen)

Abstract - Text

Introduction: Candida spp. account for approx. 10% of bloodstream infections in ICUs and are associated with a in-hospital mortality rate of 30%. Fungal biomarkers, like (1→3)-β-D-glucan (BDG) or mannan (Mn), have proven to be useful in the rapid diagnosis of candidemia. However, data on the serum levels of these biomarkers before and after the diagnosis of candidemia are scarce.

Goals: To determine if the diagnosis of candidemia can be established earlier by measurement of serum BDG and Mn and to examine if the levels of these biomarkers are reflecting treatment response.

Methods: The study was performed at the University Hospital Erlangen between August 2015 and May 2017. All serum samples from patients with culture-proven candidemia were collected. The sera were obtained from Clinical Chemistry which stores all samples for 7 days. This enabled us to get access to sera from the 4 to 5 days prior to blood culture sampling (day 0). For follow-up purposes, all serum samples after day 0 were collected until death or discharge. Furthermore, clinical data were acquired.

BDG and Mn levels were measured with the Fungitell assay and the Platelia Candida Ag Plus assay according to the manufacturers" instructions.

Results: In total, 707 serum samples from 88 candidemia episodes were analyzed. C. albicans was the most common pathogen (48%) followed by C. glabrata (30%) and C. parapsilosis (9%). In-hospital mortality was 40% and 44% of the patients with a fatal outcome died within 7 days after day 0.

The median BDG and Mn levels at day 0 were 229 pg/ml and 32 pg/ml, respectively. Using the manufacturers´ cut-offs the sensitivity of BDG and Mn at this time point was 73% and 33%, respectively.

The median time span from day 0 to blood culture positivity was 2 days. In contrast, BDG and Mn levels were elevated up to 6 days before day 0 in 43% and 30% of patients, respectively. During follow-up, decreasing BDG and Mn levels were associated with survival at the end of antimycotic therapy in 70% and 86% of patients, respectively. Furthermore, increasing BDG and Mn levels were associated with death in 63% and 60% of patients, respectively.

Summary: Serum BDG has superior sensitivity in comparison to Mn for the diagnosis of candidemia. Biomarker positivity often precedes culture positivity and enables earlier diagnosis and initiation of therapy. Decreasing biomarker levels during follow-up suggest a favorable outcome whereas increasing levels do not predict death.