The human innate and adaptive immune systems consist of effector cells producing cytokines (interleukins, interferons, chemokines, and numerous other mediators). Usually, a fragile equilibrium of pro- and anti-inflammation effects is maintained by complex regulatory mechanisms. Disturbances of this homeostasis can lead to intricate chain reactions resulting in a massive release of cytokines. This may result in a drastic self-reinforcement of various feedback mechanisms, which can ultimately lead to systemic damage, multi-organ failure, or death. Not only pathogens can initiate such disturbances, but also congenital diseases or immunomodulatory therapies. Due to the complex and diverse interactions within the innate and adaptive immune systems, the understanding of this important clinical syndrome is incomplete to date and effective therapeutic approaches remain scarce.

Septic shock, defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, is a highly lethal condition that causes substantial morbidity and mortality among critically ill patients. One of the hallmarks of sepsis is the excessive release of cytokines and other inflammatory mediators causing refractory hypotension, tissue damage, metabolic acidosis and ultimately multiple organ failure. In this context, cytokine reduction by hemoadsorption represents a new concept for blood purification, developed to attenuate the overwhelming systemic levels of pro-inflammatory and anti-inflammatory mediators released in the early phase of sepsis. In the present case series, we evaluated the impact of a new hemoadsorption device (CytoSorb) used as adjunctive therapy, on hemodynamics and clinically relevant outcome parameters in 26 critically ill patients with septic shock and in need of renal replacement therapy. We found that treatment of these patients with septic shock was associated with hemodynamic stabilization and a reduction in blood lactate levels. Actual mortality in the overall patient population was lower than mortality predicted by acute physiology and chronic health evaluation II (APACHE II). These effects seem to be more pronounced in patients in whom therapy started within 24 h of sepsis diagnosis, whereas a delay in the start of therapy was associated with a poor response to therapy in terms of reduction of catecholamine demand and survival. Moreover, from our patient population, medical patients seemed to benefit more than post-surgical patients in terms of survival. Treatment using the CytoSorb device was safe and well-tolerated with no device-related adverse events during or after the treatment sessions. Hemoadsorption using CytoSorb resulted in rapid hemodynamic stabilization and increased survival, particularly in patients in whom therapy was started early. Given the positive clinical experience of this case series, randomized controlled trials are urgently needed to define the potential benefits of this new treatment option.

Tissue-resident memory-like T _H 17 cells are clonally expanded in bronchoalveolar lavage fluid of patients with severe COVID-19.

Male sex was repeatedly identified as a risk factor for death and intensive care admission. However, it is yet unclear whether sex hormones are associated with disease severity in COVID-19 patients. In this study, we analysed sex hormone levels (estradiol and testosterone) of male and female COVID-19 patients (n = 50) admitted to an intensive care unit (ICU) in comparison to control non-COVID-19 patients at the ICU (n = 42), non-COVID-19 patients with the most prevalent comorbidity (coronary heart diseases) present within the COVID-19 cohort (n = 39) and healthy individuals (n = 50). We detected significantly elevated estradiol levels in critically ill male COVID-19 patients compared to all control cohorts. Testosterone levels were significantly reduced in critically ill male COVID-19 patients compared to control cohorts. No statistically significant differences in sex hormone levels were detected in critically ill female COVID-19 patients, albeit similar trends towards elevated estradiol levels were observed. Linear regression analysis revealed that among a broad range of cytokines and chemokines analysed, IFN-γ levels are positively associated with estradiol levels in male and female COVID-19 patients. Furthermore, male COVID-19 patients with elevated estradiol levels were more likely to receive ECMO treatment. Thus, we herein identified that disturbance of sex hormone metabolism might present a hallmark in critically ill male COVID-19 patients.

Purpose To investigate whether (1 → 3)-β-d-Glucan (BDG)-guidance shortens time to antifungal therapy and thereby reduces mortality of sepsis patients with high risk of invasive Candida infection (ICI). Methods Multicenter, randomized, controlled trial carried out between September 2016 and September 2019 in 18 intensive care units enrolling adult sepsis patients at high risk for ICI. Patients in the control group received targeted antifungal therapy driven by culture results. In addition to targeted therapy, patients in the BDG group received antifungals if at least one of two consecutive BDG samples taken during the first two study days was ≥ 80 pg/mL. Empirical antifungal therapy was discouraged in both groups. The primary endpoint was 28-day-mortality. Results 339 patients were enrolled. ICI was diagnosed in 48 patients (14.2%) within the first 96 h after enrollment. In the BDG-group, 48.8% (84/172) patients received antifungals during the first 96 h after enrollment and 6% (10/167) patients in the control group. Death until day 28 occurred in 58 of 172 patients (33.7%) in the BDG group and 51 of 167 patients (30.5%) in the control group (relative risk 1.10; 95% confidence interval, 0.80–1.51; p = 0.53). Median time to antifungal therapy was 1.1 [interquartile range (IQR) 1.0–2.2] days in the BDG group and 4.4 (IQR 2.0–9.1, p < 0.01) days in the control group. Conclusions Serum BDG guided antifungal treatment did not improve 28-day mortality among sepsis patients with risk factors for but unexpected low rate of IC. This study cannot comment on the potential benefit of BDG-guidance in a more selected at-risk population.