Purpose: Insufficient antimicrobial exposure is associated with worse outcomes in sepsis. We evaluated whether therapeutic drug monitoring (TDM)-guided antibiotic therapy improves outcomes.Methods: Randomized, multicenter, controlled trial from January 2017 to December 2019. Adult patients (n = 254) with sepsis or septic shock were randomly assigned 1:1 to receive continuous infusion of piperacillin/tazobactam with dosing guided by daily TDM of piperacillin or continuous infusion with a fixed dose (13.5 g/24 h if eGFR ≥ 20 mL/min). Target plasma concentration was four times the minimal inhibitory concentration (range ± 20%) of the underlying pathogen, respectively, of Pseudomonas aeruginosa in empiric situation. Primary outcome was the mean of daily total Sequential Organ Failure Assessment (SOFA) score up to day 10.Results: Among 249 evaluable patients (66.3 ± 13.7 years; female, 30.9%), there was no significant difference in mean SOFA score between patients with TDM (7.9 points; 95% CI 7.1-8.7) and without TDM (8.2 points; 95% CI 7.5-9.0) (p = 0.39). Patients with TDM-guided therapy showed a lower 28-day mortality (21.6% vs. 25.8%, RR 0.8, 95% CI 0.5-1.3, p = 0.44) and a higher rate of clinical (OR 1.9; 95% CI 0.5-6.2, p = 0.30) and microbiological cure (OR 2.4; 95% CI 0.7-7.4, p = 0.12), but these differences did not reach statistical significance. Attainment of target concentration was more common in patients with TDM (37.3% vs. 14.6%, OR 4.5, CI 95%, 2.9-6.9, p < 0.001).

Objective: Current workup for the pre-operative distinction between frequent adrenocortical adenomas (ACAs) and rare but aggressive adrenocortical carcinomas (ACCs) combines imaging and biochemical testing. We here investigated the potential of plasma steroid hormone profiling by liquid chromatography tandem mass spectrometry (LC-MS/MS) for the diagnosis of malignancy in adrenocortical tumors. Design: Retrospective cohort study of prospectively collected EDTA-plasma samples in a single tertiary reference center. Methods: Steroid hormone profiling by liquid chromatography tandem mass spectrometry (LC-MS/MS) in random plasma samples and logistic regression modeling. Results: Fifteen steroid hormones were quantified in 66 ACAs (29 males; M) and 42 ACC (15 M) plasma samples. Significantly higher abundances in ACC vs ACA were observed for 11-deoxycorticosterone, progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, DHEA, DHEAS and estradiol (all P < 0.05). Maximal areas under the curve (AUC) for discrimination between ACA and ACC for single analytes were only 0.76 (estradiol) and 0.77 (progesterone), respectively. Logistic regression modeling enabled the discovery of diagnostic signatures composed of six specific steroids for male and female patients with AUC of 0.95 and 0.94, respectively. Positive predictive values in males and females were 92 and 96%, negative predictive values 90 and 86%, respectively. Conclusion: This study in a large adrenal tumor patient cohort demonstrates the value of plasma steroid hormone profiling for diagnosis of ACC. Application of LC-MS/MS analysis and of our model may facilitate diagnosis of malignancy in non-expert centers. We propose to continuously evaluate and improve diagnostic accuracy of LC-MS/MS profiling by applying machine-learning algorithms to prospectively obtained steroid hormone profiles.

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Many plant secondary metabolites exhibit some degree of biological activity in humans. It is a common observation that individual plant-derived compounds in vivo are present in the nanomolar concentration range at which they usually fail to display measurable activity in vitro. While it is debatable that compounds detected in plasma are not the key effectors of bioactivity, an alternative hypothesis may take into consideration that measurable concentrations also reside in compartments other than plasma. We analysed the binding of constituents and the metabolite δ-(3,4-dihydroxy-phenyl)-γ-valerolactone (M1), that had been previously detected in plasma samples of human consumers of pine bark extract Pycnogenol, to human erythrocytes. We found that caffeic acid, taxifolin, and ferulic acid passively bind to red blood cells, but only the bioactive metabolite M1 revealed pronounced accumulation. The partitioning of M1 into erythrocytes was significantly diminished at higher concentrations of M1 and in the presence of glucose, suggesting a facilitated transport of M1 via GLUT-1 transporter. This concept was further supported by structural similarities between the natural substrate α-D-glucose and the S-isomer of M1. After cellular uptake, M1 underwent further metabolism by conjugation with glutathione. We present strong indication for a transporter-mediated accumulation of a flavonoid metabolite in human erythrocytes and subsequent formation of a novel glutathione adduct. The physiologic role of the adduct remains to be elucidated.