Search

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.A total of 107 patients (82 male, mean age 60 ± 12 years, median body mass index 28 kg/mIn 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.

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.

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.

With increasing numbers of patients recovering from COVID-19, there is increasing evidence for persistent symptoms and the need for follow-up studies. This retrospective study included patients without comorbidities, who recovered from COVID-19 and attended an outpatient clinic at a university hospital for follow-up care and potential convalescent plasma donation. Network analysis was applied to visualize symptom combinations and persistent symptoms. Comprehensive lab-testing was ascertained at each follow-up to analyze differences regarding patients with vs without persistent symptoms. 116 patients were included, age range was 18–69 years (median: 41) with follow-ups ranging from 22 to 102 days. The three most frequent persistent symptoms were Fatigue (54%), Dyspnea (29%) and Anosmia (25%). Lymphopenia was present in 13 of 112 (12%) cases. Five of 35 cases (14%) had Lymphopenia in the later follow-up range of 80–102 days. Serum IgA concentration was the only lab parameter with significant difference between patients with vs without persistent symptoms with reduced serum IgA concentrations in the patient cohort of persistent symptoms (p = 0.0219). Moreover, subgroup analyses showed that patients with lymphopenia experienced more frequently persistent symptoms. In conclusion, lymphopenia persisted in a noticeable percentage of recovered patients. Patients with persistent symptoms had significantly lower serum IgA levels. Furthermore, our data provides evidence that lymphopenia is associated with persistence of COVID-19 symptoms.

SARS-CoV-2 infection can cause severe pneumonia (COVID-19). There is evidence that patients with comorbidities are at higher risk of a severe disease course. The role of immunosuppression in the disease course is not clear. In the present report, we first describe two cases of persisting SARS-CoV-2 viraemia with fatal outcome in patients after rituximab therapy.

(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.

(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.

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.

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.

Infection with the novel coronavirus SARS-CoV-2 triggers severe illness with high mortality in a subgroup of patients. Such a critical course of COVID-19 is thought to be associated with the development of cytokine storm, a condition seen in macrophage activation syndrome (MAS) and secondary hemophagocytic lymphohistiocytosis (HLH). However, specific data demonstrating a clear association of cytokine storm with severe COVID-19 are still lacking. The aim of this study was to directly address whether immune activation in COVID-19 does indeed mimic the conditions found in these classic cytokine storm syndromes.Levels of 22 biomarkers were quantified in serum samples from patients with COVID-19 (n = 30 patients, n = 83 longitudinal samples in total), patients with secondary HLH/MAS (n = 50), and healthy controls (n = 9). Measurements were performed using bead array assays and single-marker enzyme-linked immunosorbent assay. Serum biomarker levels were assessed for correlations with disease outcome.In patients with secondary HLH/MAS, we observed pronounced activation of the interleukin-18 (IL-18)-interferon-γ axis, increased serum levels of IL-1 receptor antagonist, intercellular adhesion molecule 1, and IL-8, and strongly reduced levels of soluble Fas ligand in the course of SARS-CoV-2 infection. These observations appeared to discriminate immune dysregulation in critical COVID-19 from the well-recognized characteristics of other cytokine storm syndromes.Serum biomarker profiles clearly separate COVID-19 from MAS or secondary HLH in terms of distinguishing the severe systemic hyperinflammation that occurs following SARS-CoV-2 infection. These findings could be useful in determining the efficacy of drugs targeting key molecules and pathways specifically associated with systemic cytokine storm conditions in the treatment of COVID-19.

Background Syndecan-1 (Sdc1) is a heparin sulfate proteoglycan expressed in intestinal epithelium, which plays a crucial role in inflammation and epithelial repair. Sdc1-knockout mice have a deteriorated course of dextran sulfate sodium-induced colitis as compared to controls. Syndecan-1 is also shed into the serum during inflammation of the epithelium. We hypothesized that an increased serum level of soluble Sdc1 is a biomarker of intestinal inflammation in ulcerative colitis (UC). Objectives To evaluate serum soluble Sdc1 as a biomarker of intestinal inflammation in UC. Material and methods This is a proof-of-concept study. Patients were recruited by the University Hospital Munster and HELIOS Albert Schweitzer Klinik Northeim (Germany). Blood samples were collected from UC patients actively suffering from this condition and those in remission. The levels of Sdc1 were measured with Diaclone CD 138 ELISA kit (Diaclone Research, Besancon, France) and routine clinical data were collected (C-reactive protein (CRP) levels, calprotectin in stool samples). Data were analyzed using SPSS software. Results Soluble Sdc1 levels were significantly elevated in the active UC group as compared to the inactive UC group (94.5 ±68.1 ng/mL compared to 28.3 ±12.6 ng/mL, p = 0.0020). The levels of Sdc1 also significantly correlated with the severity of UC as measured with the Mayo score (p = 0.0248). Receiver operating characteristic (ROC) analysis showed a good correlation of Sdc1 with an endoscopic Mayo score ≥2, with a value of 0.7747 (95% confidence interval (95% CI) = 0.5775-0.9718). A cutoff value of 37.1 ng/mL of Sdc1 showed a sensitivity of 78% and a specificity of 77%. A panel of biomarkers including CRP, hemoglobin, hematocrit, and Sdc1 was able to precisely predict active UC with an area under the curve (AUC) = 0.9395 (95% CI = 0.8509-1.0000). Conclusions Serum soluble Sdc1 correlates significantly with mucosa inflammation and Mayo score in UC. Clinical trials No. NCT02333526.

COVID-19 is a pandemic disease that causes severe pulmonary damage and hyperinflammation. Vitamin A is a crucial factor in the development of immune functions and is known to be reduced in cases of acute inflammation. This prospective, multicenter observational cross-sectional study analyzed vitamin A plasma levels in SARS-CoV-2 infected individuals, and 40 hospitalized patients were included. Of these, 22 developed critical disease (Acute Respiratory Distress Syndrome [ARDS]/Extracorporeal membrane oxygenation [ECMO]), 9 developed severe disease (oxygen supplementation), and 9 developed moderate disease (no oxygen supplementation). A total of 47 age-matched convalescent persons that had been earlier infected with SARS-CoV-2 were included as the control group. Vitamin A plasma levels were determined by high-performance liquid chromatography. Reduced vitamin A plasma levels correlated significantly with increased levels of inflammatory markers (CRP, ferritin) and with markers of acute SARS-CoV-2 infection (reduced lymphocyte count, LDH). Vitamin A levels were significantly lower in hospitalized patients than in convalescent persons (p &lt, 0.01). Of the hospitalized patients, those who were critically ill showed significantly lower vitamin A levels than those who were moderately ill (p &lt, 0.05). Vitamin A plasma levels below 0.2 mg/L were significantly associated with the development of ARDS (OR = 5.54 [1.01–30.26], p = 0.048) and mortality (OR 5.21 [1.06–25.5], p = 0.042). Taken together, we conclude that vitamin A plasma levels in COVID-19 patients are reduced during acute inflammation and that severely reduced plasma levels of vitamin A are significantly associated with ARDS and mortality.

Background: The police force has the mandate to protect citizens and enforce the law for public safety. Employment in the police force is recognized as a dangerous occupation and characterized by job-related physical hazards. Therefore, good health and adequate physical condition are necessary. This study aimed to determine cardiovascular, cardiorespiratory, and metabolic risk parameters of German police officers (POs) in comparison to POs from other nations. Methods: 55 male police officers from Germany participated in the survey. We examined anthropometric measurements, cardiovascular/metabolic risk factors and blood parameters. Additionally, we calculated 10-year cardiovascular risk using the Framingham Risk Score. The diagnosis of metabolic syndrome bases on the criteria of the International Diabetes Federation. We assessed cardiorespiratory status by exercise spirometry. Results: The analyzed group of POs demonstrated a high prevalence of pre obesity (BMI: 28.0±3.2 kg/m², waist circumference: 97.8±12.4 cm). 61.8 % of POs showed an increased waist circumference. POs showed high prevalence of abnormal values of triglyceride (n: 24, 43,6%), and systolic (n: 29, 52,7%) and diastolic (n: 27, 49%) blood pressure. The average 10-year cardiovascular risk (by Framingham) was classified as moderate (9.6 ± 7.4 %). 32 % (n: 18) of POs in our study group were diagnosed with metabolic syndrome. Maximal relative oxygen uptake of POs was 34.1 ± 8.0 ·ml/kg-1 ·min-1. Conclusions: To our knowledge, this study was one of the first to assess data on cardiovascular health, metabolic syndrome and cardiorespiratory status of police officers in Germany. The results of our study demonstrated an increased cardiovascular and metabolic risk and decreased cardiorespiratory fitness in German police officers. The present study results underline the need to implement health-promoting interventions and concepts like corporate sports activities or nutrition courses to counteract cardiovascular and metabolic risk factors. We have to reduce the subsequent development of cardiovascular and metabolic disease in this occupational group.

Background: The prone position (PP) is increasingly used in mechanically ventilated coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (ARDS) patients. However, studies investigating the influence of the PP are currently lacking in these patients. This is the first study to investigate the influence of the PP on the oxygenation and decarboxylation in COVID-19 patients. Methods: A prospective bicentric study design was used, and in mechanically ventilated COVID-19 patients, PP was indicated from a partial pressure of oxygen in arterial blood (PaO2)/fraction of inspired oxygen (FIO2) ratio of &lt, 200. Patients were left prone for 16 h each. Pressure levels, FIO2, were adjusted to ensure a PaO2 greater than 60 mmHg. Blood gas analyses were performed before (baseline 0.5 h), during (1/2/5.5/9.5/13 h), and after being in the PP (1 h), the circulatory/ventilation parameters were continuously monitored, and lung compliance (LC) was roughly calculated. Responders were defined compared to the baseline value (PaO2/FIO2 ratio increase of ≥15%, partial pressure of carbon dioxide (PaCO2) decrease of ≥2%). Results: 13 patients were included and 36 PP sessions were conducted. Overall, PaO2/FIO2 increased significantly in the PP (p &lt, 0.001). Most PaO2/FIO2 responders (29/36 PP sessions, 77%) were identified 9.5 h after turning prone (14% slow responders), while most PaCO2 responders (15/36 PP sessions, 42%) were identified 13 h after turning prone. A subgroup of patients (interval intubation to PP ≥3 days) showed less PaO2/FIO2 responders (16% vs. 77%). An increase in PaCO2 and minute ventilation in the PP showed a significant negative correlation (p &lt, 0.001). LC (median before the PP = 38 mL/cm H2O, two patients with LC &gt, 80 mL/cm H2O) showed a significant positive correlation with the 28 day survival of patients (p = 0.01). Conclusion: The PP significantly improves oxygenation in COVID-19 ARDS patients. The data suggest that they also benefit most from an early PP. A decrease in minute ventilation may result in fewer PaCO2 responders. LC may be a predictive outcome parameter in COVID-19 patients. Trial registration: Retrospectively registered.

The clinical course of COVID-19 is very heterogeneous: Most infected individuals can be managed in an outpatient setting, but a substantial proportion of patients requires intensive care, resulting in a high rate of fatalities. Recently, an association between contact to small children and mild course of COVID-19 was reported. We performed an observational study to assess the impact of previous infections with seasonal coronaviruses on COVID-19 severity. 60 patients with confirmed COVID-19 infections were included (age 30 - 82 years; 52 males, 8 females): 19 inpatients with critical disease, 16 inpatients with severe or moderate disease and 25 outpatients (age and gender matched to inpatients). Patients with critical disease had significantly lower levels of HCoV OC43- (p=0.016) and HCoV HKU1-specific (p=0.023) antibodies at the first encounter compared to other COVID-19 patients. Our results indicate that previous infections with seasonal coronaviruses might protect against a severe course of disease. This finding should be validated in other settings and could contribute to identify persons at risk before an infection.

Background: With increasing numbers of patients recovering from COVID-19, there is increasing evidence for persisting symptoms and the need for follow-up studies. Methods: This retrospective study included patients without comorbidities, who recovered from COVID-19 and attended an outpatient clinic at a university hospital for follow-up care and potential convalescent plasma donation. Network analysis was applied to visualize symptom combinations and persistent symptoms. Comprehensive lab-testing was ascertained at each follow-up to analyze differences regarding patients with vs without persistent symptoms. Results: 116 patients were included, age range was 18-69 years (median: 41) with follow-ups ranging from 22 to 102 days. The three most frequent persisting symptoms were Fatigue (54%), Dyspnea (29%) and Anosmia (25%). Lymphopenia was present in 13 of 112 (12%) cases. Five of 35 cases (14%) had Lymphopenia in the later follow-up range of 80-102 days. Serum IgA concentration was the only lab parameter with significant difference between patients with vs without persistent symptoms with reduced serum IgA concentrations in the patient cohort of persisting symptoms (p=0.0219). Conclusion: Lymphopenia persisted in a noticeable percentage of recovered patients. Moreover, higher serum IgA concentration is associated with a positive effect regarding symptom persistence.

Background: The police force has a mandate to protect citizens and enforce law for public safety. Employment in the police force is recognized as a dangerous occupation and characterized by job-related physical hazards. Therefore, good health and adequate physical condition are necessary. The aim of this study was to determine cardiovascular, cardiorespiratory and metabolic risk parameters of German police officer (POs) in comparison to POs from other nations. Methods: 55 male police officers from Germany participated in the survey. Anthropometric measurements, cardiovascular and metabolic risk factors and blood parameters were taken. 10-year cardiovascular risk was calculated by using the Framingham Risk Score. The diagnosis of metabolic syndrome was based on the criteria of the International Diabetes Federation. Cardiorespiratory status was assessed by exercise spirometry. Results: The analyzed group of POs demonstrated a high prevalence of preobesity (BMI: 28.0±3.2, waist circumference: 97.8±12.4 cm). 61.8 % of POs showed an increased waist circumference. POs shows elevated cholesterol and triglyceride values and high prevalence of abnormal systolic and diastolic blood pressure. 10-year cardiovascular system risk of examined POs were 9.6 ± 7.4 %. The cardiovascular risk profile of our examined German cohort seems to be in the higher range in comparison to international data. 32 % of POs in our study group were diagnosed with metabolic syndrome. Maximal relative oxygen uptake of POs was 34.1 ± 8.0 ml/kg-1 ·min-1. Conclusions: To our knowledge this study was one of the first to assess data on cardiovascular health, metabolic syndrome and cardiorespiratory status of police officers in Germany. The results of our study population demonstrated the high cardiovascular and metabolic risk of German police officers and displaying a decreased cardiorespiratory fitness. The present study results demonstrated the need for implementation of interventions and creating health-promoting concepts like corporate sports activities and nutrition courses to counteract cardiovascular and metabolic risk factors and the subsequent development of cardiovascular and metabolic disease in this occupational group.

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.

Background The vast majority of COVID-19 patients experience a mild disease. However, a minority suffers from critical disease with substantial morbidity and mortality. Objectives To identify individuals at risk of critical COVID-19, the relevance of a seroreactivity against seasonal human coronaviruses was analyzed. Methods We conducted a multi-center non-interventional study comprising 296 patients with confirmed SARS-CoV-2 infections from four tertiary care referral centers in Germany and France. The ICU group comprised more males, whereas the outpatient group contained a higher percentage of females. For each patient, the serum or plasma sample obtained closest after symptom onset was examined by immunoblot regarding IgG antibodies against the nucleocapsid protein (NP) of HCoV 229E, NL63, OC43 and HKU1. Results Median age was 60 years (range 18-96). Patients with critical disease (n=106) had significantly lower levels of anti-HCoV OC43 nucleocapsid protein (NP)-specific antibodies compared to other COVID-19 inpatients (p=0.007). In multivariate analysis (adjusted for age, sex and BMI), OC43 negative inpatients had an increased risk of critical disease (adjusted odds ratio (AOR) 2.68 [95% CI 1.09 - 7.05]), higher than the risk by increased age or BMI, and lower than the risk by male sex. A risk stratification based on sex and OC43 serostatus was derived from this analysis. Conclusions Our results suggest that prior infections with seasonal human coronaviruses can protect against a severe course of COVID-19. Therefore, anti-OC43 antibodies should be measured for COVID-19 inpatients and considered as part of the risk assessment for each patient. Hence, we expect individuals tested negative for anti-OC43 antibodies to particularly benefit from vaccination against SARS-CoV-2, especially with other risk factors prevailing.

Immune thrombocytopenia (ITP) results from autoimmunization against platelet antigens. Autoantibodies (aabs) are considered to represent a major mechanism of thrombocytopenia in ITP by inducing platelet clearance from the circulation. Several lines of evidence demonstrate that aabs against glycoproteins (GP) IIb/IIIa and Ib/IX are predominant in ITP patients. Both disease severity and treatment response rates to specific therapeutics have been associated with aabs patterns. GP V is a well characterized immune target in Varicella-associated and drug-induced thrombocytopenia, but has never been studied systematically in ITP. In this study, patients with a suspected diagnosis of primary ITP were included once they met pre-defined clinical inclusion criteria. The presence of GP IIb/IIIa-, GP Ib/IX, and GP V-specific aabs was investigated by monoclonal antibody immobilization of platelet antigens (MAIPA) assay, both on patients' autologous platelets (direct MAIPA) and in serum (indirect MAIPA). In addition, serum IgG fractions were prepared from all patients with a positive direct MAIPA. IgG fractions were tested by surface plasmon resonance (SPR) technology for the presence of anti-GP V aabs. Complete data sets were obtained from 1,140 qualified patients. Platelet-bound aabs were detected in 343/1,140 patients (30.1%). Of these, 222 (64.7%) had platelet-bound anti-GP V aabs, either alone (10/222), or together with other specificities (211/222). Free anti-GP V aabs were detected in 30/222 patients by indirect MAIPA, but in 88/222 by SPR. The avidity of aabs detected by both methods (n=29; R700/R350=0.73±0.14) was significantly higher than the avidity for aabs detected by SPR only (n=59; R700/R350=0.32±0.13, p < 0.001). In order to study the potential biological relevance of anti-GP V, a phagocytosis assay using CD14+ positively-selected macrophages from spleen specimens from splenectomized ITP patients was performed. Anti-GPV aabs induced a modest amount of platelet uptake above the normal human serum-incubated control. No difference was observed between high avidity and low avidity anti-GP V. The effect of anti-GPV on platelet clearance was further studied in a NOD/SCID mouse model. Freshly isolated human platelets were injected into the lateral mouse tail vein; after 30 min, IgG fractions isolated from human sera containing anti-GPV antibodies or control sera from healthy donors were injected into the other lateral tail vein, and the survival of human platelets in the mouse circulation was analyzed by taking murine blood 60, 120, 300 min and 24h after baseline. High avidity and low avidity anti-GP V aabs (n=3 per group) eliminated human platelets with no detectable difference between the groups (mean platelet survival at t=300 min: 40% [range 27-55] versus 35% [range, 16-46]). A comparable, dose-dependent platelet clearance was also obtained with monoclonal antibody SW16 against GP V. In summary, we have demonstrated that anti-GP V autoantibodies are regularly detectable in ITP patients; and that they are able to induce phagocytosis and platelet clearance. Our findings have implications for both, further development of laboratory testing, and guidance for clinical decision making. First, comparison between MAIPA and SPR reveals that free aabs may be more frequent than reported, since aabs appear to escape detection by standard laboratory methods because of low avidity. Better test methods are required. Second, predicting disease severity and/or tailoring ITP therapy can possibly not be restricted to the postulated difference between anti-GP IIb/IIIa and anti-GP Ib/IX. Prospective studies are required to understand the impact of different GP-specific platelet aabs on the clinical course of ITP including, anti-GP V. Disclosures Rummel: Celgene: Honoraria; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria; Mundipharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symbio: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Eisai: Honoraria. Bakchoul:Aspen Germany gGmbH, CLS Behring, Stago gGmbH: Honoraria; German Research Society (DFG): Research Funding; Robert Bosch gGmbH: Research Funding.