Abstract Background and Purpose NFEPP is a newly-designed pain killer selectively activating G-protein coupled mu opioid receptors in injured tissues, and therefore devoid of central side effects. However, the cellular mechanisms underlying NFEPP’s antinociceptive effects were not examined in sufficient detail so far. Here we investigated the effects of NFEPP on G-protein activation, on voltage gated calcium channels and on mu opioid receptor phosphorylation. Experimental Approach HEK293 cells stably transfected with mu opioid receptors were used to study [35S]-GTPγS binding and mu opioid receptor phosphorylation. Voltage dependent calcium currents and intracellular calcium signals were examined in rat sensory neurons. All experiments were performed at acidic and physiological pH values using NFEPP compared to the conventional mu opioid receptor agonist fentanyl. To investigate the role of G protein subunits, we used pertussis toxin and gallein. Key Results At low pH, NFEPP produced more efficient G-protein activation and reduction of calcium currents in depolarized sensory neurons. The latter was mediated by G protein βγ subunits and NFEPP-mediated MOR phosphorylation was pH-dependent. Fentanyl-induced signaling was not affected by pH changes. Conclusion and Implications Our study shows that, at low pH, MOR signaling induced by NFEPP is more effective and neuronal calcium channels are directly modulated by G protein βγ subunits dissociated from G protein αi/o subunits. Apparently, the enhanced efficacy of NFEPP is dependent on extra- rather than intracellular effects on opioid receptor function.

Improvements in medical imaging and a steady increase in computing power are leading to new possibilities in the field of cardiovascular interventions. Interventions can be planned in advance in greater detail, even to the point of simulating procedures. Nevertheless, all techniques are at an early stage of development. It is of utmost importance that tools, especially if they can be used as decision support are intensively validated and their accuracy is demonstrated. In our commentary, we summarize current techniques for guiding improvement planning, but also critically discuss the downsides of these techniques. Following the work of Kenichi and colleagues, we also discuss necessary steps in advancing new tools and techniques, particularly as they are used in routine clinical practice. We also discuss the role of artificial intelligence, which could play a crucial role in this context in the future.

Introduction and objective Drugs are a frequent cause of severe anaphylactic reactions. Clinical epidemiology of drug-induced anaphylaxis (DIA) supports the identification of the most frequent eliciting drug groups, risk factors, symptoms and treatment procedures. Our aim was to analyze data to promote better recognition and long-term management of affected individuals. Methods Data from the European Anaphylaxis Registry (2007-2019) with 1,815 cases of drug-induced anaphylaxis were analyzed regarding demographics, elicitors, symptoms, comorbidities, and treatment. Results The most frequent eliciting groups of drugs were analgesics (41.27%) – with non-steroidal anti-inflammatory drugs (NSAIDs) being the most common subgroup (65.42%) – antibiotics (33.17%), local anesthetics (7.38%) and radiocontrast media (5.18%). Adrenaline was used more often in patients with DIA (23.20%) than in anaphylaxis due to other causes (17.82%). The majority of events occurred in female patients (65.34%), although they were admitted to hospital (29.01%) or an intensive care unit (ICU) (9.61%) less often. Skin symptoms were most common (84.02%), while gastrointestinal symptoms were reported less frequently (30.25%). Compared to other anaphylactic reactions in the registry (food/insects) severe reactions occurred significantly more often in DIA (5.62% vs. 1.67%). Hospitalization (31.63%) and ICU admission rates (11.85%) were significantly higher in DIA than anaphylactic reactions to other elicitors (27.58% and 5.45%). Conclusions DIA affects middle aged females more frequently and is more severe in elderly males in the sample observed. Analgesics and antibiotics are the leading causes of DIA. Adrenaline was rarely administered to patients, even though it is recommended by guidelines.

Background: In order to determine tolerance development in hen’s egg (HE) allergic children, international guidelines recommend an oral food challenge after 6-24 months. This study aimed to assess whether parents follow this advice and factors that influence their decision. Methods: A follow-up of 158 challenge-proven HE allergic children was performed. Families who did not come to a rechallenge were contacted by phone and a standardized survey relating to the current allergy status was conducted. Logistic regression models were used to assess the effect of clinical and laboratory characteristics on the reevaluation of the allergy status. Results: 35% of the HE-allergic children conducted a rechallenge in a hospital, 27% continued avoiding HE without reevaluation and 11% performed a “home-testing” with HE. The odds ratio for patients to test for HE tolerance at home instead of in a hospital increased 7.94 times (CI:2.31-27.31) for every decrease in the severity score at the initial challenge, and 3.24 times (CI:1.26-8.33) for every decrease of the baseline specific IgE CAP-class. Tolerance of heated HE prior to reevaluation was most frequent in the home-tested (100%) and was more frequent in patients, who continued avoidance (68%) compared to those, who were rechallenged (44%). Conclusions: Our data suggest an association between reaction severity as well as specific IgE levels at initial food challenge and the choice of families whether and how to evaluate natural tolerance development in their HE-allergic child. Individualized management may be needed in order to achieve safe and effective medical care for these patients.

Systemic allergic reactions to vaccines are very rare. In this study we assessed the management and outcome suspected SARS-CoV-2 vaccine hypersensitivity. We present data of 219 individuals, who experienced symptoms suspicious for an allergic reaction after the first (n=214) or the second vaccination (n=5). 195 reactions occurred after the first application of mRNA-based vaccines (157 Comirnaty®, and 38 Spikevax®) and eighteen reactions were reported after first application of a vector vaccine (Vaxzevria®). Of these 162 experienced immediate symptoms. Skin symptoms occurred in 91 cases. The most frequent cutaneous symptom was angioedema (n=45), followed by generalized urticaria (n=36) and generalized erythema/flush (n=20). 70 patients had cardiovascular symptoms, 45 showed respiratory symptoms and gastrointestinal symptoms were recorded in 14 patients. The allergological assessment of 334 individuals (219 with reactions after COVID vaccination and 115 with a history of vaccine related reactions) showed in 17% a suspicion of sensitization against the SARS-CoV-2 vaccine and/or their ingredients defined as one positive skin test and/or BAT. The majority of the SPT/IDT with the vaccines were negative. Of the 214 patients with suspected allergic symptoms after the first vaccination, 67/67 patients tolerated the re-vaccination. In this study, 334 individuals of a cohort resembling >2000 persons presenting for an allergy workup regarding SARS-CoV-2 vaccination only 45 were diagnosed in concordance with the anaphylaxis definition of the Brighton collaboration with anaphylactic immediate hypersensitivity reaction after SARS-CoV-2 vaccination. Identifiable characteristics of these patients with suspected, but also diagnosed SARS-CoV-2 vaccine hypersensitivity were female gender and the symptom angioedema. Overall, IgE-mediated hypersensitivity towards SARS-CoV-2 vaccines is extremely low and not increased in comparison to the reported hypersensitivity for other vaccines.

Background ‘Classical’ echocardiographic signs of Fabry cardiomyopathy (FC), such as left ventricular hypertrophy (LVH), posterolateral strain deficiency (PLSD) and papillary muscle hypertrophy may have a limited diagnostic accuracy in clinical practice. Our aim was to evaluate the diagnostic value of left atrial (LA) strain impairment compared to ‘classical’ echocardiographic findings to discriminate FC. Methods In standard echocardiographic assessments, we retrospectively analyzed the diagnostic value of the “classical” red flags of FC as well as LA strain in 20 FC patients and in 20 subjects with other causes of LVH. Receiver operating characteristic (ROC) curve analysis was performed to assess the respective diagnostic accuracy. Results FC was confirmed in 20 patients by genetic testing. In the LVH group, 12 patients were classified by biopsy to have hypertrophic cardiomyopathy, two had hypertensive heart disease, and six LVH combined with borderline myocarditis. Global and regional left ventricular (LV) strain was not significantly different between groups while LA strain was significantly impaired in FC (Left atrial reservoir strain (LASr) 19.1%±8.4 in FC and 25.6%±8.9 in LVH, p=0.009; left atrial conduction strain (LAScd) -8.4%±4.9 in FC and -15.9%±8.4 in LVH, p<0.01). LAScd, with an area under the curve (AUC) of 0.81 [95% confidence interval (CI) 0.66-0.96] showed the highest diagnostic accuracy to discriminate FC. The PLSD pattern showed an AUC of 0.49, quantification of papillary muscle hypertrophy an AUC of 0.47. Conclusion Adding LA strain analysis to a comprehensive echocardiographic work-up of unclear LVH may be helpful to identify FC as a possible cause.

IntroductionSince the outbreak of COVID-19 there has been an unprecedented effort from the scientific community to develop tools to help tackle this crisis. According to the Foundation for Innovative New Diagnostics (FIND; 18 March 2021) there are 1025 commercialized SARS-CoV-2 assays currently available and an additional 98 in development, including 655 immunoassays and 437 molecular assays.1 Early in the pandemic, molecular testing using nucleic acid amplification tests (NAATs) became the pillar of COVID-19 diagnostics. Since then, the development of antigen tests, immunoassays, point-of-care, and centralized options means there are now choices to be made as to how, when, and where to deploy these technologies and many guidelines have been developed, often based on Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) guidance.2-4 However, with the rapid emergence of new technologies and new scientific data, these guidelines are very fluid and subject to change. Furthermore, while NAATs are the most sensitive diagnostic tool for COVID-19 infection,3-5 the global demand for diagnostic testing is still such that the use of labour-intensive, specialist techniques needs to be carefully considered.The aim of this review is to provide an international evaluation of real-world testing needs and to define: settings where the ‘next best’ alternatives to NAATs are appropriate; settings where NAATs may not be the best option; how to manage antigen test results; and how to manage negative NAAT results where there is still a strong clinical suspicion of COVID-19. We will further aim to set out the key considerations for defining a testing strategy. Table 1 demonstrates that each testing strategy provides different information on infection status and has different performance metrics, so the right option for the right setting needs to be carefully assessed. Here we also discuss the common challenges facing clinicians and laboratorians when interpreting and supplying COVID-19 diagnostics and provide insights into what will be needed next.Table 1. A summary of the diagnostic testing methodologies for COVID-19.

Background: Seasonal influenza is a burden for emergency departments. The aim of this study was to investigate whether point-of-care (POC) PCR testing can be used to reduce staff sick days and improve diagnostic and therapeutic procedures. Methods: Using a cross-over design, the cobas® Liat® Influenza A/B POC PCR test (Liat) was compared to standard clinical practice during the 2019/2020 influenza season. All adult patients (aged ≥18 years) with fever (≥38°C) and respiratory symptoms were included. Primary endpoints were prevalence of influenza infections in the ED and staff sick days. Secondary endpoints were frequency of antiviral and antibacterial therapy, time between admission and test result or treatment initiation, patient disposition, ED length of stay (LOS) and for in-patients mortality and LOS. Nurses were interviewed about handling and integration of POC testing. The occurrence of SARS-CoV-2 infections coincided with the second half of the study. Results: A total of 828 patients were enrolled in the study. All 375 patients of the intervention group were tested with Liat, 103 of them (27.6%) tested positive. During the intervention period staff sick days were reduced by 34.4% (p=0.023). Significantly more patients in the intervention group received antiviral therapy with neuraminidase-inhibitors (7.2% vs. 3.8%, p=0.028) and tested patients received antibiotics more frequently (40.0% vs. 31.6%, p=0.033). Patients with POC test were transferred to external hospitals significantly more often (5.6% vs. 1.3%, p=0.01). Conclusion: We conclude that POC testing for influenza is useful in the ED, especially if it is heavily frequented by patients with respiratory symptoms.

Summary Myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) are rare in both children and adults, and have been recently suggested to be an autoimmune neuroinflammatory group of disorders that are different from aquaporin-4 autoantibody associated neuromyelitis optica spectrum disorder and from classic multiple sclerosis. In vivo imaging of the MOGAD patient central nervous system has shown some distinguishing features when evaluating magnetic resonance imaging of the brain, spinal cord, optic nerves, as well as retinal imaging using optical coherence tomography. In this review, we discuss key clinical and imaging characteristics of paediatric and adult MOGAD. We describe how these imaging techniques may be used to study this group of disorders and discuss how these imaging methods have led to recent insights for consideration in future studies.

Background: The ongoing COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, represents a serious worldwide health concern. A deeper understanding of the immune response to SARS-CoV-2 will be required to refine vaccine development and efficacy as well as to evaluate long-term immunity in convalescent patients. With this in mind, we investigated the formation of SARS-CoV-2 specific BMEMORY cells from patient blood samples. Methods: A standard flow cytometry-based protocol for the detection of SARS-CoV-2 specific B cells was applied using fluorochrome-coupled SARS-CoV-2 spike (S) full-length protein. Cohorts of 26 central European convalescent mild/moderate COVID-19 patients and 14 healthy donors were assessed for the levels of SARS-CoV-2 S- specific BMEMORY cells. Results: Overall B cell composition was not affected by SARS-CoV-2 infection in convalescent patients. Our analysis of SARS-CoV-2 specific BMEMORY cells in samples collected at different time points revealed that S-protein specific B cells remain in peripheral blood at least up to 6 months after COVID-19 diagnosis. Conclusions: Detection of SARS-CoV-2 specific BMEMORY cells may improve our understanding of the long-term adaptive immunity in response to SARS-CoV-2, allowing for an improved public health response and vaccine development during the COVID-19 pandemic. Further validation of the study in larger and more diverse populations and a more extended observation period will be required.

Background: The present study aims to detect, quantify and analyze circulating nutritional antigen-specific T-cells in patients with celiac disease (CeD) as well as inflammatory bowel disease (IBD), thus comparing the specific T-cell response following barrier disruption and antigen translocation. Methods: The antigen-reactive T-cell enrichment (ARTE) technique was applied allowing for a phenotypical and functional flow cytometric analysis of rare nutritional antigen-specific T-cells, including the CeD-causing gliadin (gluten), in the peripheral blood. Results: Our study indicates that by applying the ARTE technique, differences of gluten-specific T-cells as well as the differential cytokine expression between the patient groups can be detected, even without the burdening gluten re-exposure of the patients. CeD patients, independent from the presence or absence of gluten exposure in their current diet, featured an increase of the frequency of gliadin-specific T-cells, which were characterized by a pro-inflammatory phenotype. However, only for active CeD and a consecutive small intestinal barrier breach, an increase of distinct nutritional T-cells could be detected. Accordingly, frequency as well as pro-inflammatory phenotype of nutritional antigen-specific T cells were highest in Crohn’s disease patients with small intestinal inflammation whereas no significant increase was observed in ulcerative colitis. Conclusion: In summary, the ARTE method allows not only for detection but also for functional analysis of these rare cells even in healthy subjects. Applying this method, we were able to demonstrate that for non-CeD-related nutritional antigens, small intestinal barrier breach is mandatory for a peripheral antigen-specific T-cell.

CD26, acting as a co-stimulator of T cell activation, plays an important role in the immune system. However, the role of CD26 in the differentiation of T cell subsets, especially of new paradigms of T cells, such as Th17 and Tregs, is not fully clarified. In the present study, the role of CD26 in T cell differentiation was investigated in vitro. CD26 expression was analysed in the different subsets of human peripheral blood T lymphocytes after antigen stimulation. Here, the percentage of CD4+ cells significantly increased and most of these cells were co-expressed with CD26, suggesting a close correlation of CD26 expression with the proliferation of CD4+ cells. Subsequently, after antigen stimulation, CD26 high-expressing cells (CD26high) were separated from CD26 low-expressing cells (CD26low) by magnetic cell sorting. We found that the percentages of cells secreting Th1-typical cytokines (IL-2, IFN-γ), Th17-typical cytokines (IL-6, IL-17, IL-22) or expressing Th17-typical biomarkers (IL-23R, CD161, CD196) in the CD26high group were markedly higher than in the CD26low group. In addition, a co-expression of CD26 with IL-2, IFN-γ, IL-17, IL-22, and IL-23R in lymphocytes was demonstrated by fluorescence microscopy. These results provide direct evidence that the high expression of CD26 is accompanied by the differentiation of T lymphocytes into Th1 and Th17, indicating that CD26 plays a crucial role in regulating the immune response.

CPX-351 is a promising new therapeutic option for patients with treatment related (tAML) or secondary acute myeloid leukemia (sAML). It exceeded classic 7+3 therapy in overall survival (OS) and complete remission rates (CR) while providing a similar risk profile. Until now, this sub-group of AML patients had a worse overall

Background and Purpose: COVID-19 patients treated with RAAS blockers are among the patients at highest risk of poor outcome. ACE2 is the functional receptor for SARS-CoV-2. Animal studies suggest that RAAS blockers might increase the expression of ACE2 and potentially increase the risk of SARS-Cov-2 infection. Experimental Approach and Key Results: The effect of ACE inhibitor treatment on the incidence of pneumonia in non-COVID-19 patients was analyzed in 25 studies (330,780 patients). ACE inhibitor use was associated with a 27% reduction of pneumonia risk (OR: 0.73, p<0.001). Pneumonia related death cases in ACE inhibitor treated non-COVID-19 patients were reduced by 27% (OR: 0.73, p=0.004). ARB treatment was analyzed in 10 studies (275,621 non-COVID-19 patients). The risk of pneumonia was not different between patients who did or did not use ARBs. Pooled results from 16 studies in 22,333 COVID-19 patients showed that COVID-19 related server adverse clinical outcomes (admission to ICU, need for assisted ventilation or death) were reduced by 26% when using RAAS blocking agents (OR=0.74, p=0.04). Pooled results from 10 studies in 11,514 COVID-19 patients showed that RAAS blockede reduces all-cause mortality by 41% (OR=0.59, p=0.01). Conclusion and Implications: Given the weak evidence coming from animal studies and the clear beneficial data of ACE inhibition in non-COVID-19 patients and the promising data in COVID-19 patients, the use of RAAS blocking agents in patients with SARS-CoV-2 infection is justified and should be maintained. Further clinical studies analysing ARBs and ACE inhibitors separately in COVID-19 patients are needed.

Less invasive techniques for cardiothoracic surgical procedures are designed to limit surgical trauma, but technical requirements and preoperative planning are more demanding than those for conventional sternotomy. Patient selection, interdisciplinary collaboration, and surgical skills are key factors for procedural success. Aortic valve replacement is frequently performed through an upper hemisternotomy, but the right anterior minithoracotomy represents an even less traumatic, technical advancement. Preoperative assessment of the ascending aorta in relation to the sternum is mandatory to select patients and the intercostal access site. This description of the surgical technique focuses on the specific procedural details including the obligatory planning with computed tomography, and our cannulation strategy. We also sought to define the anatomical ascending aorto-sternal relationship, as it is of utmost importance in preoperative computed tomographic planning.

Background: Chronic rhinosinusitis with and without nasal polyps (CRSwNP/ CRSsNP) is an inflammatory disease affecting the nasal and sinus mucosal lining. Here, to further characterize this heterogeneous disease, we performed an extended endotyping of CRS using the nasal tissue from CRS-patients and a new approach of expression profiling of chemokines related to Th2-type cytokine IL-5. Methods: In this case-control study, we included 66 patients with CRS (CRSwNP n=26; CRSsNP n=40) diagnosed according to the EPOS 2020 criteria. The control group (n=25) consisted of CRS-free patients scheduled for inferior turbinate surgery. The concentration of following chemokines and cytokines was determined in tissue samples obtained during routine surgery from all subjects: TARC/ CCL17, PARC/ CCL18, eotaxin/ CCL11, MCP-3/ CCL7, MIP-1α/ CCL3, IP-10/ CXCL10, ENA-78/ CCL5, and IL-5. The analysis was performed by partition-based clustering. Results: In CRS tissues, the concentration of eotaxin, TARC, total IgE, IL-5, and ECP was significantly higher than in control (p<0.005). The analysis identified seven clusters. Cluster-1 was IL-5- and inflammatory chemokines-negative (11% CRSwNP). Cluster-2 had low IL-5 concentration and elevated MCP-3/CCL7 (100% CRSsNP). Clusters -3 and -4 expressed IP-10/CXCL10 (type-1-dominated), TARC/CCL17 and eotaxin/CCL11 (both type-2-dominated) (CRSwNP 13-31%). Clusters 5-7 had high concentration of IL-5, TARC/ CCL17, PARC/ CCL18, and eotaxin/CCL11 (type-2-dominated), NP 71-100%, asthma 19-50%, N-ERD 29%. Conclusions: Our chemokine expression-based extended analysis identified distinct CRS endotype clusters, possibly impacting future diagnosis, monitoring, and biologics-based treatment of CRS.