Genetic predisposition between coronavirus disease 2019 and rheumatic diseases: A 2-sample Mendelian randomization study.

OBJECTIVE: The causalities between the coronavirus disease 2019 (COVID-19) and the risk of rheumatic diseases remain unclear. The purpose of this study was to investigate the causal effect of COVID-19 on rheumatic disease occurrence. METHODS: Single nucleotide polymorphisms (SNPs), acquired from published genome-wide association studies, were used to perform 2-sample Mendelian randomization (MR) on cases diagnosed with COVID-19 (n = 13 464), rheumatic diseases (n = 444 199), juvenile idiopathic arthritis (JIA, n = 15 872), gout (n = 69  374), systemic lupus erythematosus (SLE, n = 3094), ankylosing spondylitis (n = 75 130), primary biliary cholangitis (PBC, n = 11 375) and primary Sjögren's syndrome (n = 95 046). Three MR methods were used in the analysis based on different heterogeneity and pleiotropy using the Bonferroni correction. RESULTS: The results revealed a causality between COVID-19 and rheumatic diseases with an odds ratio (OR) of 1.010 (95% confidence interval [CI], 1.006-1.013; P = .014). In addition, we observed that COVID-19 was causally associated with an increased risk of JIA (OR 1.517; 95%CI, 1.144-2.011; P = .004), PBC (OR 1.370; 95%CI, 1.149-1.635; P = .005), but a decreased risk of SLE (OR 0.732; 95%CI, 0.590-0.908; P = .004). Using MR, 8 SNPs were identified to associate with COVID-19 and recognized as significant variables. None of them were previously reported in any other diseases. CONCLUSIONS: This is the first study to use MR to explore the impact of COVID-19 on rheumatic diseases. From a genetic perspective, we found that COVID-19 could increase the risk of rheumatic diseases, such as PBC and JIA, but decrease that of SLE, thereby suggesting a potential surge in the disease burden of PBC and JIA following the COVID-19 pandemic.

Novel Insights Into the Sulfated Glucuronic Acid-Based Anti-SARS-CoV-2 Mechanism of Exopolysaccharides From Halophilic Archaeon Haloarcula hispanica.

The pandemic caused by SARS-CoV-2 is the most widely spread disease in the 21st century. Due to the continuous emergence of variants across the world, it is necessary to expand our understanding of host-virus interactions and explore new agents against SARS-CoV-2. In this study, it was found exopolysaccharides (EPSs) from halophilic archaeon Haloarcula hispanica ATCC33960 can bind to the spike protein of SARS-CoV-2 with the binding constant KD of 2.23 nM, block the binding of spike protein to Vero E6 and bronchial epithelial BEAS-2B cells, and inhibit pseudovirus infection. However, EPSs from the gene deletion mutant △HAH_1206 almost completely lost the antiviral activity against SARS-CoV-2. A significant reduction of glucuronic acid (GlcA) and the sulfation level in EPSs of △HAH_1206 was clearly observed. Our results indicated that sulfated GlcA in EPSs is possible for a main structural unit in their inhibition of binding of SARS-CoV-2 to host cells, which would provide a novel antiviral mechanism and a guide for designing new agents against SARS-CoV-2.

Levels of stress in medical students due to COVID-19.

For medical schools, the COVID-19 pandemic necessitated examination and curricular restructuring as well as significant changes to clinical attachments. With the available evidence suggesting that medical students' mental health status is already poorer than that of the general population, with academic stress being a chief predictor, such changes are likely to have a significant effect on these students. This online, cross-sectional study aimed to determine the impact of COVID-19 on perceived stress levels of medical students, investigate possible contributing and alleviating factors, and produce recommendations for medical schools to implement during future healthcare emergencies. The majority (54.5%) of respondents reported levels of stress ranging from moderate to extreme. Higher levels of stress were significantly associated with female gender (p=0.039) and international status (p=0.031). A significant association was also noted between reported stress and the transition to online learning (p<0.0001) and online assessment formatting (p<0.0001), concerns for personal health (p<0.0001) and for the health of family members (p<0.0001). Students who reported higher stress levels were less confident in their government's management of the crisis (p=0.041). Additionally, students who reported lower stress agreed highly that their medical school had an appropriate response to the crisis (p<0.0001), had provided sufficient information regarding the crisis (p=0.015), that they trust their school in handling the continuing of their education (p=0.020) and that their school had appropriate plans in place to support the continuing of education (p=0.017).