Case report: Early detection of mesenteric ischemia by intravital microscopy in a patient with septic shock

Gut ischemia is a frequent but underdiagnosed complication, especially in critically ill intensive care patients, and represents a special diagnostic challenge that can only be solved in an interdisciplinary manner. We report a case of a 54-year-old woman with acute mesenteric ischemia (AMI) as a cause of septic shock diagnosed by intravital microscopy (IVM) 2 days before visible necrotic changes in a multimodality approach. We show that intravital microscopy can be a serious alternative for the early diagnosis of mesenteric ischemia in the hands of the skilled. We use this case to discuss the value and clinical perspective of IVM in the intensive care setting

Profound decrease of liver maximum function capacity test of isoflurane sedated patients

LiMAx 13C-methacetin breath test results should be interpreted with caution in patients sedated with isoflurane

Immunomodulation by hemoadsorption

Background: Sepsis is often associated with liver dysfunction, which is an indicator of poor outcomes. Specific diagnostic tools that detect hepatic dysfunction in its early stages are scarce. So far, the immune modulatory effects of hemoadsorption with $CytoSorb^{®}$ on liver function are unclear. Method: We assessed the hepatic function by using the dynamic $LiMAx^{®}$ test and biochemical parameters in 21 patients with sepsis or septic shock receiving $CytoSorb^{®}$ in a prospective, observational study. Points of measurement: T$_1$: diagnosis of sepsis or septic shock; T$_2$ and T$_3$: 24 h and 48 h after the start of $CytoSorb^{®}$; T$_4$: 24 h after termination of $CytoSorb^{®}$. Results: The hepatic biotransformation capacity measured by $LiMAx^{®}$ was severely impaired in up to 95 % of patients. Despite a rapid shock reversal under $CytoSorb^{®}$, a significant improvement in $LiMAx^{®}$ values appeared from T$_3$ to T$_4$. This decline and recovery of liver function were not reflected by common parameters of hepatic metabolism that remained mostly within the normal range. Conclusions: Hepatic dysfunction can effectively and safely be diagnosed with $LiMAx^{®}$ in ventilated ICU patients under $CytoSorb^{®}$. Various static liver parameters are of limited use since they do not adequately reflect hepatic dysfunction and impaired hepatic metabolism

Isoflurane, like sepsis, decreases CYP1A2 liver enzyme activity in intensive care patients

$\bf Purpose:$ Liver function of intensive care patients is routinely monitored by static blood pathology. For specific indications, liver specific cytochrome activity may be measured by the commercially available maximum liver function capacity (LiMAx) test via quantification of the cytochrome P450 1A2 (CYP1A2) dependent C-methacetin metabolism. Sedation with the volatile anesthetic isoflurane was suspected to abrogate the correlation of LiMAx test with global liver function. We hypothesized that isoflurane has a CYP1A2-activity and LiMAx test result decreasing effect. $\bf Methods:$ In this monocentric, observational clinical study previously liver healthy intensive care patients, scheduled to be changed from propofol to isoflurane sedation, were enrolled. LiMAx testing was done before, during and after termination of isoflurane sedation. $\bf Results:$ The mean LiMAx value decreased during isoflurane sedation. Septic patients ($\it n$ = 11) exhibited lower LiMAx values compared to non-septic patients ($\it n$ = 11) at all time points. LiMAx values decreased with isoflurane from 140 $\pm$ 82 to 30 $\pm$ 34 $\mu$g $kg^{−1}$ $h^{−1}$ in the septic group and from 253 $\pm$ 92 to 147 $\pm$ 131 $\mu$g $kg^{−1}$ $h^{−1}$ in the non-septic group while laboratory markers did not imply significant hepatic impairment. Lactate increased during isoflurane inhalation without clinical consequence. $\bf Conclusion:$ Sepsis and isoflurane have independently demonstrated an effect on reducing the hepatic CYP1A2-activity. A network model was constructed that could explain the mechanism through the influence of isoflurane on hypoxia inducible factor (HIF-1α) by upregulation of the hypoxia-inducible pathway and the downregulation of CYP1A2-activity via the ligand-inducible pathway. Thus, the increased anaerobic metabolism may result in lactate accumulation. The influence of isoflurane sedation on the validated correlation of global liver function with CYP1A2-activity measured by LiMAx testing needs to be investigated in more detail

Exome sequencing and optical genome mapping in molecularly unsolved cases of duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a severe progressive muscle disease that mainly affects boys due to $\it X$-linked recessive inheritance. In most affected individuals, MLPA or sequencing-based techniques detect deletions, duplications, or point mutations in the dystrophin-encoding $\it DMD$ gene. However, in a small subset of patients clinically diagnosed with DMD, the molecular cause is not identified with these routine methods. Evaluation of the 60 DMD patients in our center revealed three cases without a known genetic cause. DNA samples of these patients were analyzed using whole-exome sequencing (WES) and, if unconclusive, optical genome mapping (OGM). WES led to a diagnosis in two cases: one patient was found to carry a splice mutation in the $\it DMD$ gene that had not been identified during previous Sanger sequencing. In the second patient, we detected two variants in the fukutin gene $\it (FKTN)$ that were presumed to be disease-causing. In the third patient, WES was unremarkable, but OGM identified an inversion disrupting the $\it DMD$ gene (~1.28 Mb) that was subsequently confirmed with long-read sequencing. These results highlight the importance of reanalyzing unsolved cases using WES and demonstrate that OGM is a useful method for identifying large structural variants in cases with unremarkable exome sequencing

The impact of the COVID-19 pandemic on non-COVID induced sepsis survival

$\bf Background:$ The COVID-19 pandemic has taken a toll on health care systems worldwide, which has led to increased mortality of different diseases like myocardial infarction. This is most likely due to three factors. First, an increased workload per nurse ratio, a factor associated with mortality. Second, patients presenting with COVID-19-like symptoms are isolated, which also decreases survival in cases of emergency. And third, patients hesitate to see a doctor or present themselves at a hospital. To assess if this is also true for sepsis patients, we asked whether non-COVID-19 sepsis patients had an increased 30-day mortality during the COVID-19 pandemic. $\bf Methods:$ This is a post hoc analysis of the SepsisDataNet.NRW study, a multicentric, prospective study that includes septic patients fulfilling the SEPSIS-3 criteria. Within this study, we compared the 30-day mortality and disease severity of patients recruited pre-pandemic (recruited from March 2018 until February 2020) with non-COVID-19 septic patients recruited during the pandemic (recruited from March 2020 till December 2020). $\bf Results:$ Comparing septic patients recruited before the pandemic to those recruited during the pandemic, we found an increased raw 30-day mortality in sepsis-patients recruited during the pandemic (33% vs. 52%, $\it p$ = 0.004). We also found a significant difference in the severity of disease at recruitment (SOFA score pre-pandemic: 8 (5 - 11) vs. pandemic: 10 (8 - 13); $\it p$ < 0.001). When adjusted for this, the 30-day mortality rates were not significantly different between the two groups (52% vs. 52% pre-pandemic and pandemic, $\it p$ = 0.798). $\bf Conclusions:$ This led us to believe that the higher mortality of non-COVID19 sepsis patients during the pandemic might be attributed to a more severe septic disease at the time of recruitment. We note that patients may experience a delayed admission, as indicated by elevated SOFA scores. This could explain the higher mortality during the pandemic and we found no evidence for a diminished quality of care for critically ill sepsis patients in German intensive care units

AQP3 and AQP9

Sepsis involves an immunological systemic response to a microbial pathogenic insult, leading to a cascade of interconnected biochemical, cellular, and organ-organ interaction networks. Potential drug targets can depict aquaporins, as they are involved in immunological processes. In immune cells, AQP3 and AQP9 are of special interest. In this study, we tested the hypothesis that these aquaporins are expressed in the blood cells of septic patients and impact sepsis survival. Clinical data, routine laboratory parameters, and blood samples from septic patients were analyzed on day 1 and day 8 after sepsis diagnosis. AQP expression and cytokine serum concentrations were measured. AQP3 mRNA expression increased over the duration of sepsis and was correlated with lymphocyte count. High AQP3 expression was associated with increased survival. In contrast, AQP9 expression was not altered during sepsis and was correlated with neutrophil count, and low levels of AQP9 were associated with increased survival. Furthermore, AQP9 expression was an independent risk factor for sepsis lethality. In conclusion, AQP3 and AQP9 may play contrary roles in the pathophysiology of sepsis, and these results suggest that AQP9 may be a novel drug target in sepsis and, concurrently, a valuable biomarker of the disease

The aquaporin 3 polymorphism (rs17553719) is associated with sepsis survival and correlated with IL-33 secretion

Sepsis is a common life-threatening disease caused by dysregulated immune response and metabolic acidosis which lead to organ failure. An abnormal expression of aquaporins plays an important role in organ failure. Additionally, genetic variants in aquaporins impact on the outcome in sepsis. Thus, we investigated the polymorphism (rs17553719) and expression of aquaporin-3 ($\it AQP3$) and correlated these measurements with the survival of sepsis patients. Accordingly, we collected blood samples on several days (plus clinical data) from 265 sepsis patients who stayed in different ICUs in Germany. Serum plasma, DNA, and RNA were then separated to detect the promotor genotypes of $\it AQP3$ mRNA expression of AQP3 and several cytokines. The results showed that the homozygote CC genotype exhibited a significant decrease in 30-day survival (38.9%) compared to the CT (66.15%) and TT genotypes (76.3%) ($\it p$ = 0.003). Moreover, $\it AQP3$ mRNA expression was significantly higher and nearly doubled in the CC compared to the CT ($\it p$ = 0.0044) and TT genotypes ($\it p$ = 0.018) on the day of study inclusion. This was accompanied by an increased IL-33 concentration in the CC genotype (day 0: $\it p$ = 0.0026 and day 3: $\it p$ = 0.008). In summary, the C allele of the $\it AQP3$ polymorphism (rs17553719) shows an association with increased $\it AQP3$ expression and IL-33 concentration accompanied by decreased survival in patients with sepsis

Human cytomegalovirus seropositivity is associated with reduced patient survival during sepsis

$\bf Background$ Sepsis is one of the leading causes of death. Treatment attempts targeting the immune response regularly fail in clinical trials. As HCMV latency can modulate the immune response and changes the immune cell composition, we hypothesized that HCMV serostatus affects mortality in sepsis patients. $\bf Methods$ We determined the HCMV serostatus (i.e., latency) of 410 prospectively enrolled patients of the multicenter SepsisDataNet.NRW study. Patients were recruited according to the SEPSIS-3 criteria and clinical data were recorded in an observational approach. We quantified 13 cytokines at Days 1, 4, and 8 after enrollment. Proteomics data were analyzed from the plasma samples of 171 patients. $\bf Results$ The 30-day mortality was higher in HCMV-seropositive patients than in seronegative sepsis patients (38% vs. 25%, respectively; $\it p$ = 0.008; HR, 1.656; 95% CI 1.135–2.417). This effect was observed independent of age ($\it p$ = 0.010; HR, 1.673; 95% CI 1.131–2.477). The predictive value on the outcome of the increased concentrations of IL-6 was present only in the seropositive cohort (30-day mortality, 63% vs. 24%; HR 3.250; 95% CI 2.075–5.090; $\it p$ < 0.001) with no significant differences in serum concentrations of IL-6 between the two groups. Procalcitonin and IL-10 exhibited the same behavior and were predictive of the outcome only in HCMV-seropositive patients. $\bf Conclusion$ We suggest that the predictive value of inflammation-associated biomarkers should be re-evaluated with regard to the HCMV serostatus. Targeting HCMV latency might open a new approach to selecting suitable patients for individualized treatment in sepsis