Risk Factors for Infectious Complications following Endoscopic Retrograde Cholangiopancreatography in Liver Transplant Patients: A Single-Center Study.

Background: Liver transplant recipients often require endoscopic retrograde cholangiopancreatography (ERCP) for biliary complications, which can lead to infections. This retrospective single-center study aimed to identify risk factors for infectious complications following ERCP in liver transplant patients. Methods: A retrospective analysis was conducted on 285 elective ERCP interventions performed in 88 liver transplant patients at a tertiary care center. The primary endpoint was the occurrence of an infection following ERCP. Univariable and multivariable regression analyses, Cox regression, and log-rank tests were employed to assess the influence of various factors on the incidence of infectious complications. Results: Among the 285 ERCP interventions, isolated anastomotic stenosis was found in 175 cases, ischemic type biliary lesion (ITBL) in 103 cases, and choledocholithiasis in seven cases. Bile duct interventions were performed in 96.9% of all ERCPs. Infections after ERCP occurred in 46 cases (16.1%). Independent risk factors for infection included male sex (OR 24.19), prednisolone therapy (OR 4.5), ITBL (OR 4.51), sphincterotomy (OR 2.44), cholangioscopy (OR 3.22), dilatation therapy of the bile ducts (OR 9.48), and delayed prophylactic antibiotic therapy (>1 h after ERCP) (OR 2.93). Additionally, infections following previous ERCP interventions were associated with an increased incidence of infections following future ERCP interventions (p < 0.0001). Conclusion: In liver transplant patients undergoing ERCP, male sex, prednisolone therapy, and complex bile duct interventions independently raised infection risks. Delayed antibiotic treatment further increased this risk. Patients with ITBL were notably susceptible due to incomplete drainage. Additionally, a history of post-ERCP infections signaled higher future risks, necessitating close monitoring and timely antibiotic prophylaxis.

A comparative analysis of the doctoral regulations at the medical faculties in Germany.

Objective: In order to be allowed to use the title "Dr. med." in Germany, an independent scientific achievement under the supervision of an established scientist is necessary. The research question, analysis and results are essentially carried out and developed independently by the doctoral student. The doctorate serves as proof that the doctoral candidate is capable of independent academic work. The acquisition of scientific skills and knowledge is of particular importance in medicine, as Germany´s international competitiveness is based on the education of today´s young academics. Fair conditions and uniform quality standards for doctoral studies are therefore indispensable to attract future young scientists at an early stage. Methods: The currently valid doctoral regulations of the medical faculties in Germany were analysed with regards to the following target criteria; update date, dissertation language, possibility of publication-based dissertation and its details (number of first and total authorships, publication organ), knowledge of methods and consideration of "Good Medical Practice" (GMP), plagiarism check, review process and disputation. Results: All faculties with the right to award doctorates, and, thus 40 valid regulations were included in the analysis. This revealed a great divergence in the requirements for doctoral candidates. Although a publication-based doctorate is now possible at 93% (n=37) of the faculties, in addition to the monographic dissertation, the required first and total authorships vary from one required first authorship (n=26, 70%) to two or three first authorships (n=5, 14%), as well as some faculties having no information regarding the number of publications (n=6, 16%). The quality of the publication organ was not described in detail in seven faculties (19%). To ensure quality, requirements have increasingly been anchored in the regulations, so that 22 regulations (56%) now stipulate participation in courses on GMP or qualification programmes. The regulations leave a lot of room for manoeuvre in terms of content and do not allow for comparability of the conditions for preparing doctoral researchers. The specifications range from mere mention, to instruction, to compulsory course participation. Another means of quality assurance is the prevention of plagiarism through the applications of software systems. However, this simple and effective means is not yet mentioned in 65% of the regulations (n=26). While the other regulations make use of this possibility, it is not an obligatory application. A total of 34 regulations provide for the regular drawing up of a supervision agreement to define the rights and obligations of the actors involved. Conclusion: The analysis showed a divergent picture. Although imprecise regulations or gaps in information allow scope for design, they also prevent transparency. Despite revisions of many regulations in the past, these revisions have not led to any significant harmonisation. The implementation of standardised and structured doctoral programmes is desirable and could be tackled within the framework of the planned amendment of medical studies. This opens up the possibility of dealing efficiently with the scarce resource of time in the face of competing curriculum content and of making a doctoral project more attractive to potential young scientists at an early stage.

Elevated Liver Fibrosis Progression in Isolated PSC Patients and Increased Malignancy Risk in a PSC-IBD Cohort: A Retrospective Study.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease often associated with inflammatory bowel disease (IBD), particularly ulcerative colitis (CU), and rarely with Crohn's disease (CD). Various long-term analyses show different rates of cancer and the need for orthotopic liver transplantation (OLT) in patients with isolated PSC and with concomitant IBD, respectively. However, data on the detailed course of PSC with or without IBD are limited. We aimed to analyze the clinical disease course of PSC patients without IBD compared to PSC patients with UC and CD, respectively. A retrospective data analysis of patients with isolated PSC (n = 41) and of patients with concomitant IBD (n = 115) was performed. In detail, PSC disease characteristics including occurrence of dominant stenoses, liver cirrhosis, OLT and malignancy, as well as the temporal course of PSC activity and disease progression, were analyzed. A multivariable Cox regression model and a Fine-Gray competing risk model were further used for the independent risk factor analysis of cirrhosis development and OLT. Patients with isolated PSC were significantly older at first diagnosis than patients with PSC-IBD (39 vs. 28 years, p = 0.02). A detailed analysis of the course of PSC revealed a faster PSC progression after initial diagnosis in isolated PSC patients compared to PSC-IBD including significantly earlier diagnosis of dominant stenoses (29 vs. 74 months, p = 0.021) and faster progression to liver cirrhosis (38 vs. 103 months, p = 0.027). Patients with isolated PSC have a higher risk of developing cirrhosis than patients with PSC-IBD (Gray's test p = 0.03). OLT was more frequently performed in male patients with isolated PSC compared to males with coincident IBD (48% (n = 13) vs. 33% (n = 25), p = 0.003). Colorectal carcinoma was significantly more often diagnosed in patients with PSC-IBD than in isolated PSC (8.7% vs. 0%, p = 0.042). Patients with isolated PSC seem to have a different clinical course of disease than PSC patients with concomitant IBD characterized by a more pro-fibrotic disease course with earlier onset of liver cirrhosis and dominant stenosis but with less malignancy. These data may be interpreted as either a more progressive disease course of isolated PSC or a later diagnosis of the disease at an advanced disease stage. The different clinical courses of PSC and the underlying mechanisms of the gut-liver axis need further attention.

Humoral Immunity in Immunosuppressed IBD Patients after the Third SARS-CoV-2 Vaccination: A Comparison with Healthy Control Subjects.

INTRODUCTION: The COVID-19 pandemic is a result of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Vaccination against COVID-19 is crucial for preventing severe illness and controlling the pandemic. This study aimed to examine how immunosuppressed patients with inflammatory bowel disease (IBD) responded to the third mRNA vaccination against SARS-CoV-2. The patients were undergoing treatments such as anti-TNF (infliximab, adalimumab), anti-α4ß7 integrin (vedolizumab), anti-IL12/23 (ustekinumab) and azathioprine (purine analog). Their responses were compared to those of healthy individuals. METHODS: In this prospective study, 81 IBD patients and 15 healthy controls were enrolled 2-4 months after receiving the third mRNA vaccination. This study measured IgG antibody levels against the SARS-CoV-2 spike protein's receptor binding domain (RBD) and assessed potential neutralization capacity using a surrogate virus neutralization test (sVNT). RESULTS: Overall, immunosuppressed IBD patients (without SARS-CoV-2 infection) exhibited significantly lower levels of anti-S-IgG (anti-RBD-IgG) and binding inhibition in the sVNT after the third vaccination compared to healthy controls. Patients under anti-TNF therapy showed notably reduced anti-S-IgG levels after the booster vaccination, in contrast to those receiving ustekinumab and azathioprine (p = 0.030, p = 0.031). IBD patients on anti-TNF therapy demonstrated significantly increased anti-S-IgG levels following prior SARS-CoV-2 infection (p = 0.020). CONCLUSION: Even after the third vaccination, immunosuppressed IBD patients exhibited diminished humoral immunity compared to healthy controls, especially those on anti-TNF therapy. Cases of penetrating infections led to considerably higher antibody levels in IBD patients under anti-TNF therapy compared to uninfected patients. Further investigation through prospective studies in immunosuppressed IBD patients is needed to determine whether this effectively safeguards against future infections or severe disease.

Analysis of Urinary Glycosaminoglycans to Predict Outcome in COVID-19 and Community-Acquired Pneumonia-A Proof-of-Concept Study.

Although coronavirus disease 2019 (COVID-19) is considered a systemic disease associated with vascular inflammation and eventual destruction of the protective endothelial glycocalyx (eGC), biomarkers of eGC damage are not yet available in the clinic. The most prominent components of eGC are sulphated glycosaminoglycans (sGAGs) attached to core proteoglycans. We hypothesised that the amount of sGAG fragments shed in urine (as a surrogate for systemic eGC damage) would correlate with disease severity and outcome. Total urinary sGAG concentration was measured using an in-house optimised 1,9-dimethylmethylene blue (DMMB) assay, which is highly accurate and insensitive to interferences. The median urinary sGAG concentration was significantly higher in 67 hospitalised patients with COVID-19 compared to 72 hospitalised patients with community-acquired pneumonia (CAP). In both groups, urinary sGAG concentrations predicted a combined endpoint (including intubation and death) with an area under the receiver operator characteristic curve of 0.72 (95% CI 0.55-0.88, p = 0.01) and 0.70 (95% CI 0.57-0.83, p = 0.007), respectively. In conclusion, the inexpensive and easy-to-perform DMMB assay provides a surrogate parameter for eGC damage that may be useful for risk stratification of patients with COVID-19 and CAP.

The Renin-Angiotensin System in COVID-19: Can Long COVID Be Predicted?

(1) Background: Co-morbidities such as hypertension and cardiovascular disease are major risk factors for severe COVID-19. The renin-angiotensin system (RAS) is critically involved in their pathophysiology and is counter-balanced by both angiotensin-converting enzyme 2 (ACE2), the functional receptor of SARS-CoV-2, and the kallikrein-kinin system (KKS). Considerable research interest with respect to COVID-19 treatment is currently being directed towards the components of these systems. In earlier studies, we noticed significantly reduced carboxypeptidase N (CPN, KKS member) activity and excessive angiotensin-converting enzyme (ACE, RAS member) activity in the sera of both hospitalized COVID-19 patients and a subgroup of convalescent patients. The data had been obtained using labeled bradykinin (BK) as a reporter peptide, which is a target of both CPN and ACE. The data were supplemented with mass-spectrometry-based serum proteomic analysis. Here, we hypothesize that the degree of BK serum degradation could be indicative of Long COVID. (2) Review and Discussion: The recent literature is briefly reviewed. The fact that the levels of the BK serum degradation products did not reach normal concentrations in almost half of the patients during convalescences could have been partially due to a dysregulated RAS. (3) Conclusions: Standard tests for routine patient care in Long COVID come often back normal. We suggest that the measurement of selected members of the RAS such as ACE and angiotensin II or the use of our BK degradation assay could identify Long COVID candidates. Clinical studies are required to test this hypothesis.

Quantitative Phase Imaging Using Digital Holographic Microscopy to Assess the Degree of Intestinal Inflammation in Patients with Ulcerative Colitis.

Ulcerative colitis (UC) is characterized by chronic inflammation of the colorectum. Histological remission has emerged as a potential future treatment goal; however, the histopathological assessment of intestinal inflammation in UC remains challenging with a multitude of available scoring systems and the need for a pathologist with expertise in inflammatory bowel disease (IBD). In previous studies, quantitative phase imaging (QPI) including digital holographic microscopy (DHM) was successfully applied as an objective method for stain-free quantification of the degree of inflammation in tissue sections. Here, we evaluated the application of DHM for the quantitative assessment of histopathological inflammation in patients with UC. In our study, endoscopically obtained colonic and rectal mucosal biopsy samples from 21 patients with UC were analyzed by capturing DHM-based QPI images that were subsequently evaluated using the subepithelial refractive index (RI). The retrieved RI data were correlated with established histological scoring systems including the Nancy index (NI) as well as with endoscopic and clinical findings. As a primary endpoint, we found a significant correlation between the DHM-based retrieved RI and the NI (R2 = 0.251, p < 0.001). Furthermore, RI values correlated with the Mayo endoscopic subscore (MES; R2 = 0.176, p < 0.001). An area under the receiver operating characteristics (ROC) curve of 0.820 confirms the subepithelial RI as a reliable parameter to distinguish biopsies with histologically active UC from biopsies without evidence of active disease as determined by conventional histopathological examination. An RI higher than 1.3488 was found to be the most sensitive and specific cut-off value to identify histologically active UC (sensitivity of 84% and specificity of 72%). In conclusion, our data demonstrate DHM to be a reliable tool for the quantitative assessment of mucosal inflammation in patients with UC.

Hepatobiliary manifestations in patients with ulcerative colitis: a retrospective analysis.

Background: Inflammatory bowel diseases (IBDs) are often associated with altered liver function tests (LFTs). There is little data on the relationship between abnormal LFT and IBD. Our study aimed to evaluate the prevalence and etiology of elevated LFT in patients with ulcerative colitis (UC) and to determine whether there is an association with clinical and demographic parameters. Methods: The clinical records of the Gastroenterology Outpatients Clinic at a single center were reviewed and screened for patients with UC from 2005 to 2014. In total, 263 patients were included. Patients with Crohn's disease (CD), colitis indeterminate, and colitis of other origins were excluded. Abnormal LFT and liver injuries were analyzed. Results: A cohort of 182 patients was analyzed (114 males, 68 females; mean age = 50.2 ± 16.1 years). 58 patients had already been diagnosed with a hepatobiliary disorder. Patients with a known hepatobiliary disorder suffered from UC for a significantly longer duration. Elevated LFT in patients without known hepatobiliary disorders was 69.4%. Liver injury was found in 21.8%. A transient increase in abnormal LFT was shown in 59 patients (68.6%), a persistent increase was found in 27 patients (31.4%). Treatment with thiopurines was a risk factor for persistent elevated LFT (p = 0.029), steroids had a protective impact (p = 0.037). Conclusion: This study clearly highlights the importance of screening for hepatobiliary disorders and abnormal LFT in patients with UC, as the prevalence of hepatobiliary disorders and abnormal LFT is detected very often among this patient group.

A systematic review of prevalence of metabolic syndrome in occupational groups - Does occupation matter in the global epidemic of metabolic syndrome?

Many occupations can influence the development of metabolic syndrome (MetS). This systematic review aims to evaluate studies on MetS prevalence in different occupational groups from different countries. An integrative review of the literature was conducted within the PubMed and Web of Science databases between January 2005 and February 2022. Only studies with over 3000 subjects that presented data about the prevalence of MetS in different occupational groups were included. The classification of occupational groups was based on the statistical category of economic activities in the European Community (EC). Of a total of 1942 screened records, ten studies were included, showing that MetS is a common health (main) risk factor in all occupational groups. However, the prevalence of MetS varies between nationalities, between and within occupational groups, and between genders. The reasons for this variation appear complex and supported by several causal explanations. The prevalence of MetS was highest among women in a group of Korean skilled agricultural, forestry, and fishery workers (Prevalence: 39.2%). Similarly, among men, the highest prevalence was found in Korean equipment, machine operating, and assembling workers (Prevalence: 35.4%). Male information and communication technology professionals from the Netherlands (Prevalence: 6.2%) and Spanish female catering and hospitality, personal, and security service workers (Prevalence: 5.9%) had the lowest rates of MetS. Overall, the results indicated that valid data on this topic are insufficient, and more randomized controlled trials are needed. Moreover, the different definitions of MetS complicate the accurate comparison between studies, paving the way to achieving consensus on a universal definition of MetS.

Tularemia Presenting Solely with Cervical Lymphadenopathy and Fever.

A 52-year-old German female presented with cervical lymphadenopathy and fever. Despite the initial symptom-presentation leading to the consideration of sarcoidosis, lymphoma, tuberculosis, and toxoplasmosis, an extensive serologic and histo- and molecular pathologic workup eventually indicated a likely diagnosis of tularemia. This case brings to light that tularemia is a diagnostic challenge and requires high reliance on the epidemiological context thorough patient history, and an extensive interdisciplinary diagnostic workup.

Significantly Reduced Retinol Binding Protein 4 (RBP4) Levels in Critically Ill COVID-19 Patients.

The SARS-CoV-2 virus is the causative agent of the COVID-19 pandemic. The disease causes respiratory failure in some individuals accompanied by marked hyperinflammation. Vitamin A (syn. retinol) can exist in the body in the storage form as retinyl ester, or in the transcriptionally active form as retinoic acid. The main function of retinol binding protein 4 (RBP4), synthesized in the liver, is to transport hydrophobic vitamin A to various tissues. Vitamin A has an important role in the innate and acquired immune system. In particular, it is involved in the repair of lung tissue after infections. In viral respiratory diseases such as influenza pneumonia, vitamin A supplementation has been shown to reduce mortality in animal models. In critically ill COVID-19 patients, a significant decrease in plasma vitamin A levels and an association with increased mortality have been observed. However, there is no evidence on RBP4 in relation to COVID-19. This prospective, multicenter, observational, cross-sectional study examined RBP4 (enzyme-linked immunosorbent assay) and vitamin A plasma levels (high-performance liquid chromatography) in COVID-19 patients, including 59 hospitalized patients. Of these, 19 developed critical illness (ARDS/ECMO), 20 developed severe illness (oxygenation disorder), and 20 developed moderate illness (no oxygenation disorder). Twenty age-matched convalescent patients following SARS-CoV-2 infection, were used as a control group. Reduced RBP4 plasma levels significantly correlated with impaired liver function and elevated inflammatory markers (CRP, lymphocytopenia). RBP4 levels were decreased in hospitalized patients with critical illness compared to nonpatients (p < 0.01). In comparison, significantly lower vitamin A levels were detected in hospitalized patients regardless of disease severity. Overall, we conclude that RBP4 plasma levels are significantly reduced in critically ill COVID-19 patients during acute inflammation, and vitamin A levels are significantly reduced in patients with moderate/severe/critical illness during the acute phase of illness.

Impaired Humoral Immunity with Concomitant Preserved T Cell Reactivity in IBD Patients on Treatment with Infliximab 6 Month after Vaccination with the SARS-CoV-2 mRNA Vaccine BNT162b2: A Pilot Study.

Introduction: The Coronavirus Disease 2019 (COVID-19) pandemic has been caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The most important approach to prevent severe disease progression and to contain the pandemic is the use of COVID-19 vaccines. The aim of this study was to investigate the humoral and cellular response in immunosuppressed patients with inflammatory bowel disease (IBD) on treatment with anti-TNF (infliximab, adalimumab) and anti-α4ß7-Integrin (vedolizumab) 6 months after mRNA vaccination against SARS-CoV-2 compared to healthy subjects. Methods: In this prospective study, 20 IBD patients and 9 healthy controls were included 6 months after the second BNT162b2 vaccination. In addition to quantitative determination of IgG antibody levels against the SARS-CoV-2 receptor-binding domain (RBD) of the spike protein subunit S1, a SARS-CoV-2 surrogate neutralization test (sVNT) was used to assess potential neutralization capacity. SARS-CoV-2-specific T-cell responses were measured using an interferon-γ (IFN-γ) release assay (IGRA; Euroimmun Medical Laboratory Diagnostics, Lübeck, Germany). Results: S-IgG could still be detected in the majority of IBD patients 6 months after second vaccination. Compared to healthy controls, IBD patients treated with anti-TNF agents showed both lower neutralizing activity in sVNT (percent inhibition of ACE2 receptor binding by RBD protein) and lower IgG-S (AU/mL) antibody levels (AB) (sVNT: 79% vs. 2%, p < 0. 001; AB: 1018 AU/mL vs. 141 AU/mL, p = 0.025). In contrast, patients on therapy with vedolizumab showed no impairment in humoral immune response (sVNT, S-IgG) compared with healthy controls. Specific T-cellular reactivity was detected in 73% of IBD patients and in 67% of healthy controls independent of immunosuppressive therapy (anti-TNF., vedolizumab) (p = 0.189). Conclusion: Six months after BNT162b2 vaccination, this study found significantly decreased antibody levels in patients under anti-TNF therapy. IBD patients under anti-TNF and vedolizumab therapy had no impairment of T-cellular reactivity compared to healthy controls at this time point. Further studies with larger collectives for confirmation should follow.

Incidence and predictors of cardiac arrhythmias in patients with COVID-19 induced ARDS.

INTRODUCTION: Recent studies suggest cardiac involvement with an increased incidence of arrhythmias in the setting of coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the risk of potentially lethal arrhythmias and atrial fibrillation in patients with COVID-19-induced acute respiratory distress syndrome (ARDS) and to elicit possible predictors of arrhythmia occurrence. METHODS AND RESULTS: A total of 107 patients (82 male, mean age 60 ±â€¯12 years, median body mass index 28 kg/m2) treated for COVID-19-induced ARDS in a large tertiary university hospital intensive care unit between March 2020 and February 2021 were retrospectively analyzed. Eighty-four patients (79%) had at least moderate ARDS, 88 patients (83%) were mechanically ventilated, 35 patients (33%) received vvECMO. Forty-three patients (40%) died during their hospital stay. Twelve patients (11%) showed potentially lethal arrhythmias (six ventricular tachycardia, six significant bradycardia). Atrial fibrillation occurred in 27 patients (25%). In a multivariate logistic regression analysis, duration of hospitalization was associated with the occurrence of potentially lethal arrhythmias (p = 0.006). There was no association between possible predictive factors and the occurrence of atrial fibrillation. Invasive ventilation, antipsychotics, and the QTc interval were independently associated with acute in-hospital mortality, but this was not arrhythmia-driven as there was no association between the occurrence of arrhythmias and mortality. CONCLUSION: In this relatively young population with COVID-19-induced ARDS, the incidence of potentially lethal arrhythmias was low. While overall mortality was high in these severely affected patients, cardiac involvement and arrhythmia occurrence was not a significant driver of mortality.

Comprehensive Treatment of Hematological Patients with SARS-CoV-2 Infection Including Anti-SARS-CoV-2 Monoclonal Antibodies: A Single-Center Experience Case Series.

Patients with hematologic malignancies are at high risk of exacerbated condition and higher mortality from coronavirus disease 2019 (COVID-19). Bamlanivimab, casirivimab/imdevimab combination, and sotrovimab are monoclonal antibodies (mABs) that can reduce the risk of COVID-19-related hospitalization. Clinical effectiveness of bamlanivimab and casirivimab/imdevimab combination has been shown for the Delta variant (B.1.617.2), but the effectiveness of the latter treatment against the Omicron variant (B.1.1.529) has been suggested to be reduced. However, the tolerability and clinical usage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific mABs in patients with hematologic malignancies are less specified. We present a retrospective case series analysis of all SARS-CoV-2-infected patients with hematologic malignancies who received SARS-CoV-2-specific mABs at our facility between February and mid-December 2021. A total of 13 COVID-19 patients (pts) with at least one malignant hematologic diagnosis received SARS-CoV-2-specific mABs at our facility, with 3 pts receiving bamlanivimab and 10 pts receiving casirivimab/imdevimab combination. We observed SARS-CoV-2 clearance in five cases. Furthermore, we observed a reduction in the necessity for oxygen supplementation in five cases where the application was administered off-label. To the best of our knowledge, we present the largest collection of anecdotal cases of SARS-CoV-2-specific monoclonal antibody use in patients with hematological malignancies. Potential benefit of mABs may be reduced duration and/or clearance of persistent SARS-CoV-2 infection.

The Dysregulation of the Renin-Angiotensin System in COVID-19 Studied by Serum Proteomics: Angiotensinogen Increases with Disease Severity.

(1) Background: ACE and CPN serum activity correlated with disease severity in an earlier study of 45 hospitalized COVID-19 patients. The serum protein profile was investigated in the same cohort here to shed more light on the involvement of the renin-angiotensin system (RAS). (2) Methods: High-definition mass spectrometry-based protein expression analysis was performed, followed by multivariate statistical and network analyses. (3) Results: The protein profiles of hospitalized patients (HoP) differed significantly from those of convalescent and healthy probands. Surprisingly, HoP samples separated into six groups according to their protein profiles: group (G) 1 represented the youngest and the least afflicted patients, and G6 the oldest and critically ill patients. At least two major pathophysiological schemes were indicated based on differing involvement of the kallikrein-kinin system (KKS), the RAS and complement activation. The serum angiotensinogen concentration increased with disease severity. (4) Conclusions: The important role of the RAS in the response to COVID-19 infection was substantiated, but other pathways such as the KKS, plasminogen activation and complement activation influence the systemic response to the infection.

High Angiotensin-Converting Enzyme and Low Carboxypeptidase N Serum Activity Correlate with Disease Severity in COVID-19 Patients.

(1) Background: Angiotensin-converting enzyme 2 (ACE2) is a functional receptor of SARS-CoV-2 and counter-balances ACE in the renin-angiotensin system (RAS). An imbalance of the RAS could be associated with severe COVID-19 progression. (2) Methods: Activities of serum proteases angiotensin-converting enzyme (ACE) and carboxypeptidase N (CPN) for 45 hospitalized and 26 convalescent COVID-19 patients were investigated vs. healthy controls using labeled bradykinin (DBK) degradation with and without inhibition by captopril as a read-out. Data were correlated to clinical parameters. (3) Results: DBK degradation and CPN activity were significantly reduced gender-independently in COVID-19 and returned to normal during convalescence. ACE activity was over-active in severe disease progression; product DBK1-5 was significantly increased in critically ill patients and strongly correlated with clinical heart and liver parameters. ACE inhibitors seemed to be protective, as DBK1-5 levels were normal in moderately ill patients in contrast to critically ill patients. (4) Conclusions: CPN and ACE serum activity correlated with disease severity. The RAS is affected in COVID-19, and ACE could be a therapeutic target. Further proof from dedicated studies is needed.

Sustained Impairment in Cardiopulmonary Exercise Capacity Testing in Patients after COVID-19: A Single Center Experience.

Background: Following COVID-19, patients often present with ongoing symptoms comparable to chronic fatigue and subjective deterioration of exercise capacity (EC), which has been recently described as postacute COVID-19 syndrome. Objective: To objectify the reduced EC after COVID-19 and to evaluate for pathologic limitations. Methods: Thirty patients with subjective limitation of EC performed cardiopulmonary exercise testing (CPET). If objectively limited in EC or deteriorated in oxygen pulse, we offered cardiac stress magnetic resonance imaging (MRI) and a follow-up CPET. Results: Eighteen male and 12 female patients were included. Limited relative EC was detected in 11/30 (36.7%) patients. Limitation correlated with reduced body weight-indexed peak oxygen (O2) uptake (peakV̇O2/kg) (mean 74.7 (±7.1) % vs. 103.6 (±14.9) %, p < 0.001). Reduced peakV̇O2/kg was found in 18/30 (60.0%) patients with limited EC. Patients with reduced EC widely presented an impaired maximum O2 pulse (75.7% (±5.6) vs. 106.8% (±13.9), p < 0.001). Abnormal gas exchange was absent in all limited EC patients. Moreover, no patient showed signs of reduced pulmonary perfusion. Using cardiac MRI, diminished biventricular ejection fraction was ruled out in 16 patients as a possible cause for reduced O2 pulse. Despite noncontrolled training exercises, follow-up CPET did not reveal any exercise improvements. Conclusions: Deterioration of EC was not associated with ventilatory or pulmonary vascular limitation. Exercise limitation was related to both reduced O2 pulse and peakV̇O2/kg, which, however, did not correlate with the initial severity of COVID-19. We hypothesize that impaired microcirculation or limited peripheral O2 utilization might be causative for prolonged deterioration of EC following acute COVID-19 infection.

Humoral Immune Response in IBD Patients Three and Six Months after Vaccination with the SARS-CoV-2 mRNA Vaccines mRNA-1273 and BNT162b2.

Severe acute respiratory syndrome coronovirus-2 (SARS-CoV-2) is the cause of the coronavirus disease 2019 (COVID-19) pandemic. Vaccination is considered the core approach to containing the pandemic. There is currently insufficient evidence on the efficacy of these vaccines in immunosuppressed inflammatory bowel disease (IBD) patients. The aim of this study was to investigate the humoral response in immunosuppressed IBD patients after COVID-19 mRNA vaccination. In this prospective study, IgG antibody levels (AB) against the SARS-CoV-2 receptor-binding domain (spike-protein) were quantitatively determined. For assessing the potential neutralizing capacity, a SARS-CoV-2 surrogate neutralization test (sVNT) was employed in IBD patients (n = 95) and healthy controls (n = 38). Sera were examined prior to the first/second vaccination and 3/6 months after second vaccination. Patients showed lower sVNT (%) and IgG-S (AU/mL) AB both before the second vaccination (sVNT p < 0.001; AB p < 0.001) and 3 (sVNT p = 0.002; AB p = 0.001) and 6 months (sVNT p = 0.062; AB p = 0.061) after the second vaccination. Although seroconversion rates (sVNT, IgG-S) did not differ between the two groups 3 months after second vaccination, a significant difference was seen 6 months after second vaccination (sVNT p = 0.045). Before and three months after the second vaccination, patients treated with anti-tumor necrosis factor (TNF) agents showed significantly lower AB than healthy subjects. In conclusion, an early booster shot vaccination should be discussed for IBD patients on anti-TNF therapy.

Vaccination against SARS-CoV-2 in Patients with Inflammatory Bowel Diseases: Where Do We Stand?

Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases (IBDs). Immunosuppressive medication is the main therapeutic approach to reducing inflammation of the gastrointestinal tract. Immunocompromised patients are more vulnerable to severe courses of illness after infection with common pathogens. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the pathogen of the coronavirus disease 2019 (COVID-19) pandemic. COVID-19 leads to acute respiratory distress syndrome (ARDS) following severe pulmonal damage in a significant number of cases. The worldwide circulation of SARS-CoV-2 has led to major concerns about the management of IBD patients during the pandemic, as these patients are expected to be at greater risk of complications because of their underlying altered immunological condition and immunosuppressive therapies. Vaccination against SARS-CoV-2 is considered the main approach in containing the pandemic. Today, several vaccines have been shown to be highly effective in the prevention of SARS-CoV-2 infection and severe disease course in subjects without underlying conditions in respective registration studies. Patients with underlying conditions such as IBD and/or immunosuppressive therapies were not included in the registration studies, so little is known about effectiveness and safety of SARS-CoV-2 vaccination in immunocompromised IBD patients. This review provides an overview of the recent knowledge about vaccine response in IBD patients after vaccination against SARS-CoV-2.

Indications of Persistent Glycocalyx Damage in Convalescent COVID-19 Patients: A Prospective Multicenter Study and Hypothesis.

The COVID-19 pandemic is caused by the SARS CoV-2 virus and can lead to severe lung damage and hyperinflammation. In the context of COVID-19 infection, inflammation-induced degradation of the glycocalyx layer in endothelial cells has been demonstrated. Syndecan-1 (SDC-1) is an established parameter for measuring glycocalyx injury. This prospective, multicenter, observational, cross-sectional study analyzed SDC-1 levels in 24 convalescent patients that had been infected with SARS-CoV-2 with mild disease course without need of hospitalization. We included 13 age-matched healthy individuals and 10 age-matched hospitalized COVID-19 patients with acute mild disease course as controls. In convalescent COVID-19 patients, significantly elevated SDC-1 levels were detected after a median of 88 days after symptom onset compared to healthy controls, whereas no difference was found when compared to SDC-1 levels of hospitalized patients undergoing acute disease. This study is the first to demonstrate signs of endothelial damage in non-pre-diseased, convalescent COVID-19 patients after mild disease progression without hospitalization. The data are consistent with studies showing evidence of persistent endothelial damage after severe or critical disease progression. Further work to investigate endothelial damage in convalescent COVID-19 patients should follow.