Hypothesis: Sex-Related Differences in ACE2 Activity May Contribute to Higher Mortality in Men Versus Women With COVID-19

Salt-Responsive Gut Microbiota Induces Sex-Specific Blood Pressure Changes

BACKGROUND

Tryptophan metabolism is important in blood pressure regulation. The tryptophan-indole pathway is exclusively mediated by the gut microbiota. ACE2 (angiotensin-converting enzyme 2) participates in tryptophan absorption, and a lack of ACE2 leads to changes in the gut microbiota. The gut microbiota has been recognized as a regulator of blood pressure. Furthermore, there is ample evidence for sex differences in the gut microbiota. However, it is unclear whether such sex differences impact blood pressure differentially through the tryptophan-indole pathway.

METHODS

To study the sex-specific mechanisms of gut microbiota-mediated tryptophan-indole pathway in hypertension, we generated a novel rat model with Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats-associated protein 9)-targeted deletion of Ace2 in the Dahl salt-sensitive rat. Cecal microbiota transfers from donors of both sexes to female S recipients were performed. Also, Dahl salt-sensitive rats of both sexes were orally gavaged with indole to investigate blood pressure response.

RESULTS

The female gut microbiota and its tryptophan-indole pathway exhibited greater buffering capacity when exposed to tryptophan, due to Ace2 deficiency, and salt. In contrast, the male gut microbiota and its tryptophan-indole pathway were more vulnerable. Female rats with male cecal microbiota responded to salt with a higher blood pressure increase compared with those with female cecal microbiota. Indole, a tryptophan-derived metabolite produced by gut bacteria, increased blood pressure in male but not in female rats. Moreover, salt altered host-mediated tryptophan metabolism, characterized by reduced serum serotonin of both sexes and higher levels of kynurenine derivatives in the females.

CONCLUSIONS

We uncovered a novel sex-specific mechanism in the gut microbiota-mediated tryptophan-indole pathway in blood pressure regulation. Salt tipped the tryptophan metabolism between the host and gut microbiota in a sex-dependent manner. Our study provides evidence for a novel concept that gut microbiota and its metabolism play sex-specific roles in the development of salt-sensitive hypertension.

Identification of Novel Genomic Variants in COVID-19 Patients Using Whole-Exome Sequencing: Exploring the Plausible Targets of Functional Genomics

Covid-19 caused by SARS-CoV-2 virus has emerged as an immense burden and an unparalleled global health challenge in recorded human history. The clinical characteristics and risk factors of COVID-19 exhibit considerable variability, leading to a spectrum of clinical severity. Moreover, the likelihood of exposure to the virus may differ based on comorbidity status as comorbid illnesses have mechanisms that can considerably increase mortality by reducing the body's ability to withstand injury. The mammalian target of rapamycin (mTOR) pathway is essential for orchestrating innate immune cell defense, including cytokine production and is dysregulated in severe Coronavirus Disease 2019 (COVID-19) individuals. Through genome-wide, association studies, numerous genetic variants in the human host have been identified that have a significant impact on the immune response to SARS-CoV-2. To identify potentially significant genetic variants in Covid-19 patients that could affect the risk, severity, and clinical outcome of the infection, this study has used whole-exome sequencing (WES) on the 16 COVID-19 patients with varying comorbidities and severity of the disease including fatal outcomes. Among them, 8 patients made a full recovery and were discharged, while 8 patients unfortunately did not survive due to the severity of the illness and majority of them were males. The study identified 10,204 variants in the patients. From 1120 variants, which were chosen for novel variant analysis using mutation, function prediction tools to identify deleterious variants that could affect normal gene function, 116 variants of 57 genes were found to be deleterious. These variants were further classified as likely pathogenic and variants of uncertain significance. The data showed that among the likely pathogenic variants five genes were identified in connection to immune response whereas two were related to respiratory system. The common variants associated with the covid-19 phenotype showed the top 10 significant genes identified in this study such as ERCC2, FBXO5, HTR3D, FAIM, DNAH17, MTOR, IGHMBP2, ZNF530, QSER1, and FOXRED2 with variant rs1057079 of the MTOR gene representing the highest odds ratio (1.7, p = 8.7e-04). The mammalian target of rapamycin (mTOR) pathway variant rs1057079 was reported with high odds ratio, may orchestrate innate immune cell defense, including cytokine production, and is dysregulated. This study concluded that the mTOR signaling gene variant (rs1057079) is associated with different degrees of covid-19 severity and is essential for orchestrating innate immune cell defense including cytokine production. Inhibiting mTOR and its corresponding deleterious immune responses with medicinal approaches may provide a novel avenue for treating severe COVID-19 illness. Besides the PPI network exhibited a significantly high local clustering coefficient of 0.424 (p = 0.000536), suggesting the presence of tightly knit functional modules. These findings enhance our comprehension of the intricate interactions between genetic factors and COVID-19 disease.

Expression level of non-coding (MiR-155) gene as biomarker for severity of coronaviruses infection among vaccinated and non-vaccinated Iraqi patients

BACKGROUND

The COVID-19 pandemic caused by SARS-CoV-2 is influenced by genetic and epigenetic factors, including miR-155, which affects immune cell and virus functions and laboratory biomarkers.

OBJECTIVE

To evaluates miR-155's role as a biomarker for SARS-CoV-2 detection and monitoring, examining its significance in identifying infection in both vaccinated and unvaccinated individuals using ROC curve analysis.

METHODS

Blood samples were collected from 70 patients who attended Medical City Hospital in Baghdad from June 2022 to April 2023 and were determined to be associated with SARS-CoV-2 (35 patients were hospitalized at the Intensive Care Units due to the severity of their symptoms while the other 35 were left in the hospital upon treatment.). Additionally, 35 samples were collected as a healthy control group.

RESULTS

The expression level of miR-155 in the serum of samples showed a high level (fold change: 9.81 ± 5.50) in the severe patients' group in comparison with the moderate patients' group (fold change: 4.17 ± 2.93) and healthy group (fold change: 1.08 ± 0.01). To assess the performance of miR-155 and laboratory biomarkers, a (ROC) curve was utilized to determine the sensitivity and specificity.

CONCLUSIONS

The miR-155 gene, overexpressed in SARS-CoV-2 patients, correlates with disease activity and severity, potentially serving as a biomarker for diagnosis and a potential therapeutic target.

Blood ACE2 Protein Level Correlates with COVID-19 Severity

ACE2's impact on the severity of COVID-19 is widely discussed but still controversial. To estimate its role in aspects of the main risk factors and comorbidities, we involved post-COVID-19 patients in Ternopil region (Ukraine). The recruitment period was from July 2020 to December 2021. Medical records, treatment modalities, and outcomes were recorded and analyzed. The serum human ACE2 protein was measured with Cusabio ELISA kits (Houston, TX, USA). Statistical analysis was performed with SPSS21.0 software (SPSS Inc., Chicago, IL, USA). The level of the ACE2 serum protein was significantly higher (p < 0.001) in patients with mild symptoms compared to a more severe course of the disease, and inversely had changed from 1 to 90 days after recovery. In patients with mild COVID-19, ACE2 levels significantly decreased over time, while among critical patients, it increased by 34.1 percent. Such results could be explained by ACE2 shedding from tissues into circulation. Loss of the membrane-bound form of the enzyme decreases the virus' entry into cells. Our studies did not identify a sex-related ACE2 serum level correlation. The most common comorbidities were hypertension, cardiovascular diseases, respiratory diseases, and diabetes mellitus. All abovementioned comorbidities except respiratory diseases contribute to the severity of the disease and correlate with ACE2 blood serum levels.

The Impact of COVID-19 on People Living with HIV-1 and HIV-1-Associated Neurological Complications

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative pathogen of the coronavirus disease 2019 (COVID-19) pandemic, a fatal respiratory illness. The associated risk factors for COVID-19 are old age and medical comorbidities. In the current combined antiretroviral therapy (cART) era, a significant portion of people living with HIV-1 (PLWH) with controlled viremia is older and with comorbidities, making these people vulnerable to SARS-CoV-2 infection and COVID-19-associated severe outcomes. Additionally, SARS-CoV-2 is neurotropic and causes neurological complications, resulting in a health burden and an adverse impact on PLWH and exacerbating HIV-1-associated neurocognitive disorder (HAND). The impact of SARS-CoV-2 infection and COVID-19 severity on neuroinflammation, the development of HAND and preexisting HAND is poorly explored. In the present review, we compiled the current knowledge of differences and similarities between SARS-CoV-2 and HIV-1, the conditions of the SARS-CoV-2/COVID-19 and HIV-1/AIDS syndemic and their impact on the central nervous system (CNS). Risk factors of COVID-19 on PLWH and neurological manifestations, inflammatory mechanisms leading to the neurological syndrome, the development of HAND, and its influence on preexisting HAND are also discussed. Finally, we have reviewed the challenges of the present syndemic on the world population, with a particular emphasis on PLWH.

Patients with COPD hospitalized due to COVID-19 in Spain: a comparison between the first and second wave

OBJECTIVE

This work aimed to compare the characteristics, progress, and prognosis of patients with COPD hospitalized due to COVID-19 in Spain in the first wave with those of the second wave.

MATERIAL AND METHODS

This is an observational study of patients hospitalized in Spain with a diagnosis of COPD included in the SEMI-COVID-19 registry. The medical history, symptoms, analytical and radiological results, treatment, and progress of patients with COPD hospitalized in the first wave (from March to June 2020) versus those hospitalized in the second wave (from July to December 2020) were compared. Factors associated with poor prognosis, defined as all-cause mortality and a composite endpoint that included mortality, high-flow oxygen therapy, mechanical ventilation, and ICU admission, were analyzed.

RESULTS

Of the 21,642 patients in the SEMI-COVID-19 Registry, 6.9% were diagnosed with COPD: 1128 (6.8%) in WAVE1 and 374 (7.7%) in WAVE2 (p = 0.04). WAVE2 patients presented less dry cough, fever and dyspnea, hypoxemia (43% vs 36%, p < 0.05), and radiological condensation (46% vs 31%, p < 0.05) than WAVE1 patients. Mortality was lower in WAVE2 (35% vs 28.6%, p = 0.01). In the total sample, mortality and the composite outcome of poor prognosis were lower among patients who received inhalation therapy.

CONCLUSIONS

Patients with COPD admitted to the hospital due to COVID-19 in the second wave had less respiratory failure and less radiological involvement as well as a better prognosis. These patients should receive bronchodilator treatment if there is no contraindication for it.

[Patients with COPD hospitalized due to COVID-19 in Spain: a comparison between the first and second wave]

Objective

This work aimed to compare the characteristics, progress, and prognosis of patients with COPD hospitalized due to COVID-19 in Spain in the first wave with those of the second wave.

Material and methods

This is an observational study of patients hospitalized in Spain with a diagnosis of COPD included in the SEMI-COVID-19 registry. The medical history, symptoms, analytical and radiological results, treatment, and progress of patients with COPD hospitalized in the first wave (from March to June 2020) versus those hospitalized in the second wave (from July to December 2020) were compared. Factors associated with poor prognosis, defined as all-cause mortality and a composite endpoint that included mortality, high-flow oxygen therapy, mechanical ventilation, and ICU admission, were analyzed.

Results

Of the 21,642 patients in the SEMI-COVID-19 Registry, 6.9% were diagnosed with COPD: 1,128 (6.8%) in WAVE1 and 374 (7.7%) in WAVE2 (p = 0.04). WAVE2 patients presented less dry cough, fever and dyspnea, hypoxemia (43% vs 36%, p < 0.05), and radiological condensation (46% vs 31%, p < 0.05) than WAVE1 patients. Mortality was lower in WAVE2 (35% vs 28.6%, p = 0.01). In the total sample, mortality and the composite outcome of poor prognosis were lower among patients who received inhalation therapy.

Conclusions

Patients with COPD admitted to the hospital due to COVID-19 in the second wave had less respiratory failure and less radiological involvement as well as a better prognosis. These patients should receive bronchodilator treatment if there is no contraindication for it.

Anthropometric Measurements and Admission Parameters as Predictors of Acute Respiratory Distress Syndrome in Hospitalized COVID-19 Patients

Aim: We aimed to single out admission predictors of acute respiratory distress syndrome (ARDS) in hospitalized COVID-19 patients and investigate the role of bioelectrical impedance (BIA) measurements in ARDS development. Method: An observational, prospective cohort study was conducted on 407 consecutive COVID-19 patients hospitalized at the University Clinical Center Kragujevac between September 2021 and March 2022. Patients were followed during the hospitalization, and ARDS was observed as a primary endpoint. Body composition was assessed using the BMI, body fat percentage (BF%), and visceral fat (VF) via BIA. Within 24 h of admission, patients were sampled for blood gas and laboratory analysis. Results: Patients with BMI above 30 kg/m², very high BF%, and/or very high VF levels were at a significantly higher risk of developing ARDS compared to nonobese patients (OR: 4.568, 8.892, and 2.448, respectively). In addition, after performing multiple regression analysis, six admission predictors of ARDS were singled out: (1) very high BF (aOR 8.059), (2) SaO₂ < 87.5 (aOR 5.120), (3) IL-6 > 59.75 (aOR 4.089), (4) low lymphocyte count (aOR 2.880), (5) female sex (aOR 2.290), and (6) age < 68.5 (aOR 1.976). Conclusion: Obesity is an important risk factor for the clinical deterioration of hospitalized COVID-19 patients. BF%, assessed through BIA measuring, was the strongest independent predictor of ARDS in hospitalized COVID-19 patients.

Long COVID and risk of erectile dysfunction in recovered patients from mild to moderate COVID-19

Patients with coronavirus disease 2019 (COVID-19) were shown to have reduced serum testosterone levels compared to healthy individuals. Low testosterone levels are linked with the development of erectile dysfunction (ED). In this case-controlled study, 20 healthy controls and 39 patients with ED 3 months after recovering from mild-to-moderate COVID-19 pneumonia were studied. The patients ranged in age from 31 to 47 years. To identify early and late COVID-19 infections, real-time polymerase-chain reaction (RT-PCR) and COVID-19 antibody testing were done. The levels of luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), free testosterone (FT), free androgenic index (FAI), and sex hormone-binding globulin (SHBG) were measured. The sexual health inventory for patients (SHIM) score was used to measure the erectile function of the patients and controls. When compared to the controls, the TT serum level in long COVID-19 (LC) patients with ED was low (p = 0.01). In contrast to controls, FT and FAI were both lower in LC patients with ED. (p = 0.001). FSH serum levels did not significantly differ (p = 0.07), but in ED patients, LH serum levels were elevated. SHIM scores were associated with low TT (p = 0.30), FT (p = 0.09), and high LH (p = 0.76) in LC patients with ED. Male patients with decreased serum levels of LH and testosterone may have hypothalamic-pituitary-gonadal axis dysfunction, which could lead to the development of LC-induced ED. Therefore, an in-depth research is necessary to confirm the causal link between COVID-19 and ED in LC patients.

Neurology of Systemic Disease

Sex differences exist within the neurologic complications of systemic disease. To promote new avenues for prevention and develop novel therapeutics, we highlight the role of sex in differential outcomes to infectious disease and cardiac arrest and educate the reader in paraneoplastic presentations that may herald underlying malignancies in women.

Assessment of Liver Regeneration in Patients Who Have Undergone Living Donor Hepatectomy for Living Donor Liver Transplantation

BACKGROUND

Inflammation and the associated immune pathways are among the most important factors in liver regeneration after living donor hepatectomy. Various biomarkers, especially liver function tests, are used to show liver regeneration. The aim of this study was to evaluate the course of liver regeneration following donor hepatectomy (LDH) by routine and regeneration-related biomarkers.

METHOD

Data from 63 living liver donors (LLDs) who underwent LDH in Inonu University Liver Transplant Institute were prospectively analyzed. Serum samples were obtained on the preoperative day and postoperative days (POD) 1, 3, 5, 10, and 21. Regenerative markers including alfa-fetoprotein (AFP), des carboxy prothrombin (DCP), ornithine decarboxylase (ODC), retinol-binding protein 4 (RBP4), and angiotensin-converting enzyme isotype II (ACEII) and liver function tests including alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP) and total bilirubin levels were all analyzed.

RESULTS

The median age of the LLDs was 29.7 years and 28 LLDs were female. Eight LLDs developed postoperative complications requiring relaparotomy. The routine laboratory parameters including AST (<0.001), ALT (<0.001), ALP (<0.001), and total bilirubin (<0.001) showed a significant increase over time until postoperative day (POD) 3. For the regeneration-related parameters, except for the RBP4, all parameters including ACEII (p = 0.006), AFP (p = 0.002), DCP (p = 0.007), and ODC (p = 0.002) showed a significant increase in POD3. The regeneration parameters showed a different pattern of change. In right-lobe liver grafts, ACEII (p = 0.002), AFP (p = 0.035), and ODC (p = 0.001) showed a significant increase over time. DCP (p = 0.129) and RBP4 (p = 0.335) showed no significant changes in right-lobe liver grafts.

CONCLUSIONS

Regenerative markers are increased in a sustained fashion following LDH. This is more prominent following right-lobe grafts which are indicative of progenitor-associated liver regeneration.

Associations between chronic conditions and death in hospital among adults (aged 20+ years) during first acute care hospitalizations with a confirmed or suspected COVID-19 diagnosis in Canada

PURPOSE

We aimed to quantify life course-specific associations between death in hospital and 30 chronic conditions, and comorbidity among them, in adults (aged 20+ years) during their first acute care hospitalization with a confirmed or suspected COVID-19 diagnosis in Canada.

METHODS

We identified 35,519 first acute care hospitalizations with a confirmed or suspected COVID-19 diagnosis in the Discharge Abstract Database as of March 31, 2021. For each of five life-course age groups (20-34, 35-49, 50-64, 65-79, and 80+ years), we used multivariable logistic regression to examine associations between death in hospital and 30 chronic conditions, comorbidity, period of admission, and pregnant status, after adjusting for sex and age.

RESULTS

About 20.9% of hospitalized patients with COVID-19 died in hospital. Conditions most strongly associated with in-hospital death varied across the life course. Chronic liver disease, other nervous system disorders, and obesity were statistically significantly associated (α = 0.05) with in-hospital death in the 20-34 to 65-79 year age groups, but the magnitude of the associations decreased as age increased. Stroke (aOR = 5.24, 95% CI: 2.63, 9.83) and other inflammatory rheumatic diseases (aOR = 4.37, 95% CI: 1.64, 10.26) were significantly associated with in-hospital death among 35 to 49 year olds only. Among 50+ year olds, more chronic conditions were significantly associated with in-hospital death, but the magnitude of the associations were generally weaker except for Down syndrome in the 50 to 64 (aOR = 8.49, 95% CI: 4.28, 16.28) and 65 to 79 year age groups (aOR = 5.19, 95% CI: 1.44, 20.91). Associations between comorbidity and death also attenuated with age. Among 20 to 34 year olds, the likelihood of death was 19 times greater (aOR = 18.69, 95% CI: 7.69, 48.24) in patients with three or more conditions compared to patients with none of the conditions, while for 80+ year olds the likelihood of death was two times greater (aOR = 2.04, 95% CI: 1.70, 2.45) for patients with six or more conditions compared to patients with none of the conditions.

CONCLUSION

Conditions most strongly associated with in-hospital death among hospitalized adults with COVID-19 vary across the life course, and the impact of chronic conditions and comorbidity attenuate with age.

Association investigations between ACE1 and ACE2 polymorphisms and severity of COVID-19 disease

Due to the unique affinity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the angiotensin-converting enzyme 2 (ACE2) receptor in patients, the foremost recent evidence indicated that ACE1 and ACE2 polymorphisms could affect the susceptibility of individuals to SARS-CoV-2 infection and also the disease outcome. Here, we aimed to assess the possible association between two polymorphisms and the severity of disease in patients. In the present study, 146 patients with COVID-19 who were admitted to the Mazandaran University of Medical Sciences hospitals between March 2020 and July 2020 were enrolled in this case-control study. The patients were divided into four groups based on clinical symptoms and severity of the diseases (mild, moderate, severe, and critical). After DNA extraction, the ACE gene I/D polymorphism (rs4646994) and ACE2 gene polymorphism (rs2285666) were genotyped using Gap-PCR and PCR-RFLP techniques, respectively. Then, five samples from each obtained genotype were confirmed by Sanger sequencing technique. Data were analyzed with SAS software version 9.1 using appropriate statistical procedures. The ACE gene I/D polymorphism (rs4646994) genotypes were classified into three types: I/I, I/D, and D/D. Our finding indicated that the prevalence of ACE1 D/D genotype was significantly higher in severe and critical COVID-19 patients (P = 0.0016). Additionally, the analysis revealed a remarkable association between rs4646994 SNP and the HB and ESRI levels in patients (P < 0.05). Although the ACE2 rs2285666 SNP was not related to the severity of disease, this variant was significantly associated with ALT, ESRI, and P. These results provide preliminary evidence of a genetic association between the ACE-D/D genotype and the D allele of ACE1 genotype and the disease severity. Therefore, our findings might be useful for identifying the susceptible population groups for COVID-19 therapy.

Admission Predictors of Mortality in Hospitalized COVID-19 Patients-A Serbian Cohort Study

Background: Early prediction of COVID-19 patients’ mortality risk may be beneficial in adequate triage and risk assessment. Therefore, we aimed to single out the independent morality predictors of hospitalized COVID-19 patients among parameters available on hospital admission. Methods: An observational, retrospective−prospective cohort study was conducted on 703 consecutive COVID-19 patients hospitalized in the University Clinical Center Kragujevac between September and December 2021. Patients were followed during the hospitalization, and in-hospital mortality was observed as a primary end-point. Within 24 h of admission, patients were sampled for blood gas and laboratory analysis, including complete blood cell count, inflammation biomarkers and other biochemistry, coagulation parameters, and cardiac biomarkers. Socio-demographic and medical history data were obtained using patients’ medical records. Results: The overall prevalence of mortality was 28.4% (n = 199). After performing multiple regression analysis on 20 parameters, according to the initial univariate analysis, only four independent variables gave statistically significant contributions to the model: SaO2 < 88.5 % (aOR 3.075), IL-6 > 74.6 pg/mL (aOR 2.389), LDH > 804.5 U/L (aOR 2.069) and age > 69.5 years (aOR 1.786). The C-index of the predicted probability calculated using this multivariate logistic model was 0.740 (p < 0.001). Conclusions: Parameters available on hospital admission can be beneficial in predicting COVID-19 mortality.

The sex and gender dimensions of COVID-19: A narrative review of the potential underlying factors

Multiple lines of evidence indicate that the male sex is a significant risk factor for severe disease and mortality due to coronavirus disease 2019 (COVID-19). However, the precise explanation for the discrepancy is currently unclear. Immunologically, the female-biased protection against COVID-19 could presumably be due to a more rapid and robust immune response to viruses exhibited by males. The female hormones, e.g., estrogens and progesterone, may have protective roles against viral infections. In contrast, male hormones, e.g., testosterone, can act oppositely. Besides, the expression of the ACE-2 receptor in the lung and airway lining, which the SARS-CoV-2 uses to enter cells, is more pronounced in males. Estrogen potentially plays a role in downregulating the expression of ACE-2, which could be a plausible biological explanation for the reduced severity of COVID-19 in females. Comorbidities, e.g., cardiovascular diseases, diabetes, and kidney disorders, are considered significant risk factors for severe outcomes in COVID-19. Age-adjusted data shows that males are statistically more predisposed to these morbidities-amplifying risks for males with COVID-19. In addition, many sociocultural factors and gender-constructed behavior of men and women impact exposure to infections and outcomes. In many parts of the world, women are more likely to abide by health regulations, e.g., mask-wearing and handwashing, than men. In contrast, men, in general, are more involved with high-risk behaviors, e.g., smoking and alcohol consumption, and high-risk jobs that require admixing with people, which increases their risk of exposure to the infection. Overall, males and females suffer differently from COVID-19 due to a complex interplay between many biological and sociocultural factors.

The immune response to COVID-19: Does sex matter?

The coronavirus disease 2019 (COVID-19) pandemic has created unprecedented challenges worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and has a complex interaction with the immune system, including growing evidence of sex-specific differences in the immune response. Sex-disaggregated analyses of epidemiological data indicate that males experience more severe symptoms and suffer higher mortality from COVID-19 than females. Many behavioural risk factors and biological factors may contribute to the different immune response. This review examines the immune response to SARS-CoV-2 infection in the context of sex, with emphasis on potential biological mechanisms explaining differences in clinical outcomes. Understanding sex differences in the pathophysiology of SARS-CoV-2 infection will help promote the development of specific strategies to manage the disease.

The Effects of Biological Sex and Cardiovascular Disease on COVID-19 Mortality

Cardiovascular disease (CVD) is a common comorbidity observed in patients with COVID-19 that is associated with increased severity and mortality. However, the effects of biological sex on CVD associated mortality in COVID-19 patients is poorly established particularly among Hispanic/Latin Americans. We examined the association of preexisting CVD with COVID-19 mortality in hospitalized Latin American men and women. This multicenter study included hospitalized Mexican patients with a positive diagnosis of COVID-19. The main outcome was in-hospital mortality. Multivariable regression analyses were used to calculate the adjusted odd ratios with 95% confidence interval for mortality in women and men. Of 81,400 patients with a positive diagnosis for SARS-CoV-2 infection, 28,929 (35.54%) hospitalized patients were evaluated. Of these, the 35.41% (10,243) were women. In-hospital death was higher in men than in women. In relation to CVD between the sexes, women had a higher incidence of CVD than men (4.69% vs 3.93%. P=0.0023). The adjusted logistic regression analyses showed that CVD was significantly associated with COVID-19 mortality in women but not men. We then stratified by sex according to age <52 and ≥52 years old. Similar significant association was also found in pre-specified analysis in women ≥52 years old but not in men of similar age. We conclude that CVD's effect on mortality among COVID-19 hospitalized patients is dependent on biological sex and age in this Latin American cohort. These results suggest that therapeutic strategies for Latin American women with CVD and COVID-19 should include particular attention to their cardiovascular health.

Severe COVID-19 Is Characterised by Perturbations in Plasma Amines Correlated with Immune Response Markers, and Linked to Inflammation and Oxidative Stress

The COVID-19 pandemic raised a need to characterise the biochemical response to SARS-CoV-2 infection and find biological markers to identify therapeutic targets. In support of these aims, we applied a range of LC-MS platforms to analyse over 100 plasma samples from patients with varying COVID-19 severity and with detailed clinical information on inflammatory responses (>30 immune markers). The first publication in a series reports the results of quantitative LC-MS/MS profiling of 56 amino acids and derivatives. A comparison between samples taken from ICU and ward patients revealed a notable increase in ten post-translationally modified amino acids that correlated with markers indicative of an excessive immune response: TNF-alpha, neutrophils, markers for macrophage, and leukocyte activation. Severe patients also had increased kynurenine, positively correlated with CRP and cytokines that induce its production. ICU and ward patients with high IL-6 showed decreased levels of 22 immune-supporting and anti-oxidative amino acids and derivatives (e.g., glutathione, GABA). These negatively correlated with CRP and IL-6 and positively correlated with markers indicative of adaptive immune activation. Including corresponding alterations in convalescing ward patients, the overall metabolic picture of severe COVID-19 reflected enhanced metabolic demands to maintain cell proliferation and redox balance, alongside increased inflammation and oxidative stress.

Effect of diabetes on short-term mortality and incidence of first hospitalizations for cardiovascular events after recovery from SARS-CoV-2 infection

AIM

To evaluate the impact of diabetes and COVID-19 on all-cause-mortality and first hospitalizations for cardiovascular events (CVE): myocardial infarction or stroke, within six months after being tested positive and having recovered from SARS-CoV-2 infection.

METHODS

Resident population in Tuscany, Italy of age 45-94 yr without prior hospitalization for CVE, tested positive for SARS-CoV-2 by March 1st, 2020 and afterwards recovering from COVID-19 was compared with age, gender and diabetes matched controls without infection, for incidence rate ratio (IRR) of all-cause-deaths or first CVE at six months follow up.

RESULTS

46,152 subjects of whom 4,597 with diabetes, tested positive and recovered from SARS-CoV-2 were compared with 1:1 age, gender and diabetes matched controls without infection. COVID-19 was associated with higher all-cause-mortality: IRR:1.92(95 %CI:1.63-2.25) while diabetes with increased risk of first CVE hospitalizations: IRR:2.24(2.18-4.25). Co-presence of COVID-19 and diabetes didn't add any additional excess risk. Being women and statins' use significantly reduced death risk.

CONCLUSIONS

After recovery from COVID-19, independently of diabetes, all-cause-mortality risk at six months was twofold increased, while risk of first CVE hospitalization remained unmodified. Diabetes, independently of prior COVID-19, resulted in higher six-months risk of first CVE not of death. Female gender and statins' use reduced both excess risks.

Relation of vitamin D to COVID-19

The coronavirus pandemic has lasted for more than a year now and still remains the leading cause of concern, worldwide. The causal agent; SARS- CoV-2, leads to the development of respiratory distress in the lower respiratory tract, sometimes leading to fatalities. Keeping in mind the discovery of mutant strains across the world, as well as the delay in vaccinations across vast populations, most people speculate boosting their immune systems as a preventive and precautionary measure. One of the most commonly observed conditions that hamper immunity; Vitamin D deficiency has been linked to the onset and the alteration of course of the disease in patients and is also being explored as a potential drug supplement. These surmises make it essential to study deep into the speculations. This review aims to overview the possible correlations between Vitamin D and COVID-19.

Placental Expression of ACE2 and TMPRSS2 in Maternal Severe Acute Respiratory Syndrome Coronavirus 2 Infection: Are Placental Defenses Mediated by Fetal Sex?

BACKGROUND

Expression of angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine protease (TMPRSS2), host molecules required for viral entry, may underlie sex differences in vulnerability to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We investigated whether placental ACE2 and TMPRSS2 expression vary by fetal sex in the presence of maternal SARS-CoV-2 infection.

METHODS

Placental ACE2 and TMPRSS2 expression was quantified by quantitative reverse transcription polymerase chain reaction (RT-PCR) and by Western blot in 68 pregnant women (38 SARS-CoV-2 positive, 30 SARS-CoV-2 negative) delivering at Mass General Brigham from April to June 2020. The impact of fetal sex and maternal SARS-CoV-2 exposure on ACE2 and TMPRSS2 was analyzed by 2-way analysis of variance (ANOVA).

RESULTS

Maternal SARS-CoV-2 infection impacted placental TMPRSS2 expression in a sexually dimorphic fashion (2-way ANOVA interaction, P = .002). We observed no impact of fetal sex or maternal SARS-CoV-2 status on ACE2. TMPRSS2 expression was significantly correlated with ACE2 expression in males (Spearman ρ = 0.54, P = .02) but not females (ρ = 0.23, P = .34) exposed to maternal SARS-CoV-2.

CONCLUSIONS

Sex differences in placental TMPRSS2 but not ACE2 were observed in the setting of maternal SARS-CoV-2 infection, which may have implications for offspring vulnerability to placental infection.

Analysis of Covid-19 Hospital Admissions in Ivano-Frankivsk, Ukraine

The Covid-19 pandemic has a substantial impact on socioeconomic, political, demographic, and other aspects of life. Effective healthcare is, however, a primary determinant of successful fighting against Covid-19. The analysis of local healthcare indicators serves as a source for estimating pandemic magnitude and the adaptation of healthcare at a national level. In this study, the rates of Covid-19 hospital admissions to the Ivano-Frankivsk City Hospital, Ukraine, from April 2020 to May 2021 were analysed. All cases were grouped by age, sex, and the type of admission; data were analyzed monthly and seasonally. The peaks of hospital admissions were observed in November 2020 and March 2021; however, the highest mortality rates were seen from August to November 2020. The analysis of age- and sex-disaggregated Covid-19 mortality data showed the predominance of elderly males (61.9%, 66.6 ± 3.9 years) over females (38.1%, 71.8 ± 2.3 years). The ratio of hospital admissions was unstable: the percentage of emergency, GP-referred and self-referred admissions was similar from April to May 2020; however, GP-referred admissions prevailed, and the number of self-referral patients decreased twice between March and May 2021. In conclusions, the trends in hospital admissions were similar to those reported in other studies. However, the differences in time frames and socio-demographic characteristics were observed that highlights the importance of considering regional, social and geographic aspects of the population when improving the capacity of healthcare system and establishing effective preventive measures against the pandemic at the local level.

A Population-Based Registry Analysis on Hospitalized COVID-19 Patients with Previous Cardiovascular Disease: Clinical Profile, Treatment, and Predictors of Death

A high percentage of patients with COVID-19 (coronavirus disease 2019) have previous cardiovascular disease (CVD). The findings presented here came from an epidemiological population-based registry study (real-world data) that enrolled all in-hospital COVID-19 patients with previous CVD from 1 March to 31 May 2020. Death, other comorbidities, hospital stay variables, ventilation type, and main clinical outcomes were evaluated. In Castile and Leon, 35.83% of the 7307 in-hospital COVID-19 patients who participated in this study had previous CVD, particularly arrhythmias (48.97%), cerebrovascular disease (25.02%), ischemic heart disease (22.8%), and chronic heart failure (20.82%). Of the patients, 21.36% were men and more than 90% were over 65 years of age, and the mortality rate achieved 32.93%. The most used medicines were antibiotics (91.41%), antimalarials (73.3%), steroids (46.64%), and antivirals (43.16%). The main predictors of death were age over 65 years (OR: 5), ventilation needs (OR: 2.81), treatment with anti-SIRS (systemic inflammatory response syndrome) medicines (OR: 1.97), antivirals (OR: 1.74) or steroids (OR: 1.68), SIRS (OR: 5.75), SARS (severe acute respiratory syndrome) (OR: 2.44), or AKI (acute kidney injury) (OR: 1.63) occurrence. Chronic heart failure and cerebrovascular disease were associated with a worse clinical course of COVID-19, especially in men older than 65 years with diabetes who developed SIRS, SARS, or AKI.

In-hospital use of ACE inhibitors/angiotensin receptor blockers associates with COVID-19 outcomes in African American patients

BACKGROUNDThe angiotensin-converting enzyme (ACE) D allele is more prevalent among African Americans compared with other races and ethnicities and has previously been associated with severe coronavirus disease 2019 (COVID-19) pathogenesis through excessive ACE1 activity. ACE inhibitors/angiotensin receptor blockers (ACE-I/ARB) may counteract this mechanism, but their association with COVID-19 outcomes has not been specifically tested in the African American population.METHODSWe identified 6218 patients who were admitted into Mount Sinai hospitals with COVID-19 between February 24 and May 31, 2020, in New York City. We evaluated whether the outpatient and in-hospital use of ACE-I/ARB is associated with COVID-19 in-hospital mortality in an African American compared with non-African American population.RESULTSOf the 6218 patients with COVID-19, 1138 (18.3%) were ACE-I/ARB users. In a multivariate logistic regression model, ACE-I/ARB use was independently associated with a reduced risk of in-hospital mortality in the entire population (OR, 0.655; 95% CI, 0.505-0.850; P = 0.001), African American population (OR, 0.44; 95% CI, 0.249-0.779; P = 0.005), and non-African American population (OR, 0.748, 95% CI, 0.553-1.012, P = 0.06). In the African American population, in-hospital use of ACE-I/ARB was associated with improved mortality (OR, 0.378; 95% CI, 0.188-0.766; P = 0.006), whereas outpatient use was not (OR, 0.889; 95% CI, 0.375-2.158; P = 0.812). When analyzing each medication class separately, ARB in-hospital use was significantly associated with reduced in-hospital mortality in the African American population (OR, 0.196; 95% CI, 0.074-0.516; P = 0.001), whereas ACE-I use was not associated with impact on mortality in any population.CONCLUSIONIn-hospital use of ARB was associated with a significant reduction in in-hospital mortality among COVID-19-positive African American patients.FUNDINGNone.

Testosterone Deficiency Is a Risk Factor for Severe COVID-19

Background

Male sex is related to increased COVID-19 severity and fatality although confirmed infections are similarly distributed between men and women. The aim of this retrospective analysis was to investigate the impact of sex hormones on disease progression and immune activation in men with COVID-19.

Patients and Methods

We studied for effects of sex hormones on disease severity and immune activation in 377 patients (230 men, 147 women) with PCR-confirmed SARS-CoV-2 infections hospitalized at the Innsbruck University Hospital between February and December 2020.

Results

Men had more severe COVID-19 with concomitant higher immune system activation upon hospital admission when compared to women. Men with a severe course of infection had lower serum total testosterone (tT) levels whereas luteinizing hormone (LH) and estradiol (E2) levels were within the normal range. tT deficiency was associated with elevated CRP (rs = - 0.567, p < 0.001), IL-6 levels (rs = - 0.563, p < 0.001), lower cholesterol levels (rs = 0.407, p < 0.001) and an increased morbidity and mortality. Men with tT levels < 100 ng/dL had a more than eighteen-fold higher in-hospital mortality risk (OR 18.243 [95%CI 2.301 - 144.639], p = 0.006) compared to men with tT levels > 230 ng/dL. Moreover, while morbidity and mortality showed a positive correlation with E2 levels at admission, we detected a negative correlation with the tT/E2 ratio upon hospital admission.

Conclusion

Hospitalized men with COVID-19 present with rather low testosterone levels linked to more advanced immune activation, severe clinical manifestations translating into an increased risk for ICU admission or death. The underlying mechanisms remain elusive but may include infection driven hypogonadism as well as inflammation mediated cholesterol reduction causing gonadotropin suppression and impaired androgen formation. Finally, in elderly late onset hypogonadism might also contribute to lower testosterone levels.

Alternate Roles of Sox Transcription Factors beyond Transcription Initiation

Sox proteins are known as crucial transcription factors for many developmental processes and for a wide range of common diseases. They were believed to specifically bind and bend DNA with other transcription factors and elicit transcriptional activation or repression activities in the early stage of transcription. However, their functions are not limited to transcription initiation. It has been showed that Sox proteins are involved in the regulation of alternative splicing regulatory networks and translational control. In this review, we discuss the current knowledge on how Sox transcription factors such as Sox2, Sry, Sox6, and Sox9 allow the coordination of co-transcriptional splicing and also the mechanism of SOX4-mediated translational control in the context of RNA polymerase III.

Sex and age differences in COVID-19 mortality in Europe

AIM

To examine the magnitude of sex differences in survival from the coronavirus disease 2019 (COVID-19) in Europe across age groups and regions. We hypothesized that men have a higher mortality than women at any given age but that sex differences will decrease with age as only the healthiest men survive to older ages.

METHODS

We used population data from the Institut National D'Études Démographiques on cumulative deaths due to COVID-19 from February to June 2020 in 10 European regions: Denmark, Norway, Sweden, The Netherlands, England and Wales, France, Germany, Italy, Spain and Portugal. For each region, we calculated cumulative mortality rates stratified by age and sex and corresponding relative risks for men vs. women.

RESULTS

The relative risk of dying from COVID-19 was higher for men than for women in almost all age groups in all regions. The overall relative risk ranged from 1.11 (95% confidence interval, CI 1.01-1.23) in Portugal to 1.54 (95% CI 1.49-1.58) in France. In most regions, sex differences increased until the ages of 60-69 years, but decreased thereafter with the smallest sex difference at age 80+ years.

CONCLUSION

Despite variability in data collection and time coverage among regions, the study showed an overall similar pattern of sex differences in COVID-19 mortality in Europe.

The Physiological Mechanisms of the Sex-Based Difference in Outcomes of COVID19 Infection

The scale of the SARS-CoV-2 pandemic has thrust a spotlight on the sex-based differences in response to viral diseases; morbidity and mortality are greater in men than women. We outline the mechanisms by which being female offers a degree of protection from COVID19, that persists even when confounders such as comorbidities are considered. The physiological and immunological mechanisms are fascinating and range from incomplete X chromosome inactivation of immune genes, a crucial role for angiotensin converting enzyme 2 (ACE2), and regulation of both immune activity and ACE2 by sex steroids. From this flows understanding of why lung and other organs are more susceptible to COVID19 damage in men, and how their distinct immunological landscapes need to be acknowledged to guide prognosis and treatment. Pregnancy, menopause, and hormone replacement therapy bring changed hormonal environments and the need for better stratification in COVID19 studies. We end by noting clinical trials based on increasing estrogens or progesterone or anti-testosterone drugs; excellent examples of translational physiology.