Immune-Response Patterns and Next Generation Sequencing Diagnostics for the Detection of Mycoses in Patients with Septic Shock—Results of a Combined Clinical and Experimental Investigation

Abstract

Fungi are of increasing importance in sepsis. However, culture-based diagnostic procedures are associated with relevant weaknesses. Therefore, culture- and next-generation sequencing (NGS)-based fungal findings as well as corresponding plasma levels of β-d-glucan, interferon gamma (INF-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-2, -4, -6, -10, -17A, and mid-regional proadrenomedullin (MR-proADM) were evaluated in 50 septic patients at six consecutive time points within 28 days after sepsis onset. Furthermore, immune-response patterns during infections with Candida spp. were studied in a reconstituted human epithelium model. In total, 22% (n = 11) of patients suffered from a fungal infection. An NGS-based diagnostic approach appeared to be suitable for the identification of fungal pathogens in patients suffering from fungemia as well as in patients with negative blood cultures. Moreover, MR-proADM and IL-17A in plasma proved suitable for the identification of patients with a fungal infection. Using RNA-seq., adrenomedullin (ADM) was shown to be a target gene which is upregulated early after an epithelial infection with Candida spp. In summary, an NGS-based diagnostic approach was able to close the diagnostic gap of routinely used culture-based diagnostic procedures, which can be further facilitated by plasmatic measurements of MR-proADM and IL-17A. In addition, ADM was identified as an early target gene in response to epithelial infections with Candida spp.

Soluble Intercellular Adhesion Molecule- (sICAM-) 1, Thrombospondin-1, and Vinculin for the Identification of Septic Shock Patients Suffering from an Invasive Fungal Infection

“…Study Design. Data result from secondary analyses of an already published observational clinical study [21], which was approved by the local ethics committee (Ethics Committee of the Medical Faculty of Heidelberg, Trial Code No. S-097/2013/German Clinical Trials Register: DRKS00005463).…”

“…Statistical Analyses. Ratio calculations after MS analysis were performed as described elsewhere [21]. All study data were entered into an electronic database ( for the identification of septic shock patients suffering from an IFI was assessed using a logistic regression model and/or receiver operating characteristic (ROC) analyses.…”

“…As previously described throughout our workgroup, the diagnostic performance of procalcitonin (PCT), BDG, and CRP for early IFI detection within the presented cohort of septic shock patients was poor [21]. However, the combination of these routinely used infection biomarkers (e.g., PCT) and innovative fungal biomarkers (e.g., MR-proADM, sICAM-1, and IL-17A) was shown to improve the Figure 3: Plasma concentrations of thromospondin-1 for the detection of an IFI in patients with septic shock.…”

“…Common diagnostic procedures for the identification of patients suffering from an IFI (such as culture-based diagnostics or plasma levels of β-D-glucan (BDG)) are associated with relevant weaknesses, so that a considerable number of IFI cases might be missed [20][21][22]. Moreover, this diagnostic insufficiency is associated with a delayed initiation of antifungal therapy, associated with the abovementioned increased mortality rates [23].…”

“…Moreover, this diagnostic insufficiency is associated with a delayed initiation of antifungal therapy, associated with the abovementioned increased mortality rates [23]. New diagnostic approaches such as polymerase chain reaction-(PCR-) or even nextgeneration sequencing-(NGS-) based methods have yet to demonstrate, whether they are of value for the detection of an IFI in daily clinical use [21,24]. Therefore, there is an urgent need for innovative fungal biomarkers, reliably identifying septic patients suffering from an IFI and guiding antifungal therapy in these patients.…”