Risk factors for worsening of somatic symptom burden in a prospective cohort during the COVID-19 pandemic

Aims: Little is known about risk factors for both Long COVID and somatic symptoms that develop in individuals without a history of COVID-19 in response to the pandemic. There is reason to assume an interplay between pathophysiological mechanisms and psychosocial factors in the etiology of symptom persistence. This study investigates specific risk factors for somatic symptom deterioration in a cohort of German adults with and without prior SARS-CoV-2 infection. Method(s): German healthcare professionals underwent SARS-CoV-2 IgG antibody testing and completed self-rating questionnaires at baseline and 21 months later between April 2020 and February 2022. Differences in variables between the time points were analyzed and a regression analysis was performed to predict somatic symptom deterioration at follow-up. Result(s): Seven hundred fifty-one adults completed both assessments. Until follow-up, n = 58 had contracted SARS-CoV-2 confirmed by serology. Between baseline and follow-up, signs of mental and physical strain increased significantly in the sample. Symptom expectations associated with COVID-19 and a self-reported history of COVID-19, but not serologically confirmed SARS-CoV-2 infection, significantly predicted somatic symptom deterioration at follow-up. A further predictor was baseline psychological symptom burden. Conclusion(s): This study supports a disease-overarching biopsychosocial model for the development of burdensome somatic symptoms during the COVID-19 pandemic and supports research findings that symptom burden may be more related to the psychosocial effects of the pandemic than to infection itself. Future studies on Long COVID should include SARS-CoV-2 negative control groups and consider symptom burden prior to infection in order to avoid an overestimation of prevalence rates.Copyright © 2023

FXR INHIBITION AS A NEW STRATEGY AGAINST COVID19 T Brevini1, M Maes2, GJ Webb3, CD Fuchs4, G Buescher5

Introduction: Vaccines revolutionised the management of COVID19. Nevertheless, they lack efficacy in high-risk or vulnerable groups (e.g., immunosuppressed patients), who may not mount an appropriate immune response. Monoclonal antibodies represent the gold-standard agents for such cases;but they are limited by availability, need for parenteral administration and the risk for viral escape because of spike protein mutations. Therefore, there is a pressing need for new prophylactic agents less prone to resistance.The viral receptor ACE2 represents an ideal target as it is essential for viral entry and transmission and because being a host protein it is not affected by viral mutations. However, the regulation of ACE2 remains elusive, due to the lack of appropriatein vitromodels. Cholangiocytes show one of the highest ACE2 expression levels in the body, representing an ideal platform for these studies. Here, we use cholangiocyte organoids as proof-of-principleto identify that the bile acid receptor FXR regulates ACE2 expression and SARS-CoV-2 infectionin vitro. We validate these findings in lung and gut organoids, animal models, human organs perfusedex situand patient cohorts. Aims & Methods: 1. Identify pathways controlling the transcriptional regulation of ACE2 2. Identify drugs modulating these pathways as novel prophylactic and therapeutic agents for COVID19. Organoids were propagated using established protocols. Marker expression was assessed using single-cell RNA sequencing, QPCR, and immunofluorescence. FXR binding on DNA was assessed with chromatin immunoprecipitation. SARS-CoV-2 was isolated from bronchoalveolar lavage of a COVID19 patient. Syrian golden hamsters were infected via direct inoculation and QPCR on oral swab, nasal turbinate and lung samples was used to measure SARS-CoV-2 infection. Human livers and lungs not used for transplantation were perfusedex-situusing normothermic perfusion. Nasopharyngeal swabs were used to measure ACE2 expression in nasal epithelial cells of healthy individuals taking UDCA at the standard therapeutic dose of 15 mg/kg/day. Patient registry data were compared using propensity score matching for sex, age, diabetes, NAFLD and Child- Turcotte-Pugh score. Result(s): We identified that FXR directly regulates ACE2 transcription in cholangiocyte organoids, while FXR inhibition with the approved drug ursodeoxycholic acid (UDCA), reduced ACE2 expression and SARS-CoV-2 infectionin vitro. We confirmed this mechanism in organoids from other COVID19-affected tissues, including the respiratory and intestinal systems. We validated our findingsin vivoin Syrian golden hamsters, showing that treatment with UDCA downregulates ACE2 and prevents SARS-CoV-2 infection. We confirmed that UDCA reduces ACE2 and SARS-CoV-2 infection in human lungs and livers perfusedex-situ. We performed a clinical study demonstrating that UDCA lowers ACE2 levels in the nasal epithelium of 6 healthy volunteers. Finally, we identified a correlation between UDCA and better clinical outcomes (hospitalisation, ICU admission and death) in COVID19 patients receiving UDCA for cholestatic diseases using the COVID-Hep and SECURELiver registry data. Conclusion(s): We identified FXR as a novel regulator of ACE2 expression. Using a bench-to-bedside approach combining in vitroand in vivomodels, exsituperfused human organs and clinical data we showed that FXR inhibition prevents or reduces SARS-CoV-2 infection and identified UDCA as an approved, cost-effective drug which could be repurposed for COVID19, paving the road for future clinical trials.

Fxr as a new therapeutic target for COVID-19

Background: Despite recent advances, the management of COVID19 is complicated by vaccine availability, the modest efficacy of existing treatments, and the potential for viral resistance. Therefore, there is a pressing need for new prophylactic and therapeutic agents. Modifying the expression of the SARS-CoV-2 entry receptor ACE2 could prevent viral infection and limit disease progression. Here, we identify that ACE2 expression is controlled by the transcription factor farnesoid X receptor (FXR) and demonstrate that ACE2 downregulation through FXR antagonism, using approved drugs, such as ursodeoxycholic acid (UDCA), could represent a novel therapeutic strategy to complement current approaches. Methods: Primary cholangiocyte, pulmonary and intestinal organoids were propagated using established protocols. Marker expression was assessed using singlecell RNA sequencing, QPCR, immunofluorescence and flow cytometry. FXR binding on DNA was assessed with chromatin immunoprecipitation. SARS-CoV-2 was isolated from bronchoalveolar lavage of a COVID19 patient. Viral load was measured via QPCR. Human livers not used for transplantation were perfused ex-situ using the metra (OrganOx) normothermic perfusion device. Serum ACE2 activity was measured with commercial kits. Patient data from the COVID-Hep and SECURE-Liver registries were compared using propensity score matching. Results: FXR activation directly upregulated ACE2 transcription in organoids from COVID19 affected tissues, including the biliary, gastrointestinal and respiratory systems. Conversely, FXR antagonism with z-guggulsterone or UDCA, had the opposite effect. Importantly, both drugs reduced susceptibility to SARS-CoV-2 infection in lung, cholangiocyte and gut organoids. Furthermore, systemic administration of UDCA in human organs perfused ex-situ downregulated ACE2 and reduced SARS-CoV-2 infection ex-vivo. Oral UDCA rapidly reduced serum ACE2 in vivo. Registry data showed a correlation between UDCA administration and better clinical outcomes in COVID19 patients, including hospitalisation, ICU admission, mechanical ventilation and death. Conclusion: We discovered FXR as a novel therapeutic target against SARS-CoV-2 and we identified approved FXR inhibitors which could be repurposed to potentially treat COVID19, paving the road for future clinical trials to validate these results.

Fxr antagonists as new agents for COVID19

Introduction The management of COVID19 is complicated by vaccine availability, the modest efficacy of existing treatments, and the potential for viral resistance. Therefore, there is a pressing need for new prophylactic and therapeutic agents. The viral receptor ACE2 is an ideal target as it is required for SARS-CoV-2 entry in host cells. Modifying ACE2 expression could prevent infection and/or limit disease progression. Nevertheless, the mechanisms controlling ACE2 expression remain elusive. Aims To identify pathways controlling the transcriptional regulation of ACE2, and exploit them to reduce SARS-CoV-2 infection. Methods Organoids from primary biliary, intestinal and pulmonary epithelia were derived and cultured as previously described. Single-cell RNA sequencing, QPCR, immunofluorescence and flow cytometry were used to assess marker expression. Chromatin immunoprecipitation was used to assess FXR binding on DNA. Bronchoalveolar lavage SARS-CoV-2 patient isolates were used for infection experiments. Human livers not used for transplantation were connected to the metra (OrganOx) normothermic perfusion device and perfused ex-situ using therapeutic doses of UDCA for 12 hours. ACE2 activity was measured following manufacturer's instructions. Patient data from the COVID-Hep and SECURE-Liver registries were compared using propensity score matching for sex, age and Child-Turcotte-Pugh score. Results We first demonstrated that cholangiocytes are susceptible to SARS-CoV-2 infection in vivo and in organoid culture. We then used cholangiocyte organoids to identify FXR as a transcriptional regulator of ACE2. We validated our results in pulmonary and intestinal organoids, showing that ACE2 regulation by FXR represents a broad mechanism present in multiple COVID19-affected tissues. We then demonstrated that approved FXR inhibitors, such as ursodeoxycholic acid (UDCA) and z-guggulsterone (ZGG), decrease ACE2 levels and reduce viral infection in vitro in primary biliary, intestinal and pulmonary organoids. We interrogated the impact of systemic UDCA administration in human livers perfused ex-situ, demonstrating reduced ACE2 levels and SARS-CoV-2 infection. Furthermore, we showed that commencing UDCA treatment lowers ACE2 levels in primary biliary cholangitis (PBC) patients. Finally, we identified a correlation between UDCA treatment and better clinical outcome in COVID-19 patients, including hospitalisation, ICU admission, mechanical ventilation and death, using registry data. Conclusion We identified FXR as a novel master regulator of ACE2 expression. Using a bench-to-bedside approach we combined in vitro, ex-vivo and patient data to demonstrate the efficacy of ACE2 downregulation against SARS-CoV-2 infection and identified approved and inexpensive drugs (UDCA, ZGG) which could be repurposed as prophylactic and therapeutic agents against SARS-CoV-2 infection, paving the road for future clinical trials.

SARS-CoV-2 Reinfection in a Healthcare Worker Despite the Presence of Detectable Neutralizing Antibodies

So far, only a few reports about reinfections with SARS-CoV-2 have been published, and they often lack detailed immunological and virological data. We report about a SARS-CoV-2 reinfection with a genetically distinct SARS-CoV-2 variant in an immunocompetent female healthcare worker that has led to a mild disease course. No obvious viral escape mutations were observed in the second virus variant. The infectious virus was shed from the patient during the second infection episode despite the presence of neutralizing antibodies in her blood. Our data indicate that a moderate immune response after the first infection, but not a viral escape, did allow for reinfection and live virus shedding.