Sex-Based Differences in Susceptibility to Severe Acute Respiratory Syndrome Coronavirus Infection

Outbreaks of SARS-CoV-2 in naturally infected mink farms: Impact, transmission dynamics, genetic patterns, and environmental contamination

SARS-CoV-2 infection outbreaks in minks have serious implications associated with animal health and welfare, and public health. In two naturally infected mink farms (A and B) located in Greece, we investigated the outbreaks and assessed parameters associated with virus transmission, immunity, pathology, and environmental contamination. Symptoms ranged from anorexia and mild depression to respiratory signs of varying intensity. Although the farms were at different breeding stages, mortality was similarly high (8.4% and 10.0%). The viral strains belonged to lineages B.1.1.218 and B.1.1.305, possessing the mink-specific S-Y453F substitution. Lung histopathology identified necrosis of smooth muscle and connective tissue elements of vascular walls, and vasculitis as the main early key events of the acute SARS-CoV-2-induced broncho-interstitial pneumonia. Molecular investigation in two dead minks indicated a consistently higher (0.3-1.3 log10 RNA copies/g) viral load in organs of the male mink compared to the female. In farm A, the infected farmers were responsible for the significant initial infection of 229 out of 1,000 handled minks, suggesting a very efficient human-to-mink transmission. Subsequent infections across the sheds wherein animals were being housed occurred due to airborne transmission. Based on a R0 of 2.90 and a growth rate equal to 0.293, the generation time was estimated to be 3.6 days, indicative of the massive SARS-CoV-2 dispersal among minks. After the end of the outbreaks, a similar percentage of animals were immune in the two farms (93.0% and 93.3%), preventing further virus transmission whereas, viral RNA was detected in samples collected from shed surfaces and air. Consequently, strict biosecurity is imperative during the occurrence of clinical signs. Environmental viral load monitoring, in conjunction with NGS should be adopted in mink farm surveillance. The minimum proportion of minks that need to be immunized to avoid outbreaks in farms was calculated at 65.5%, which is important for future vaccination campaigns.

Sex and Gender Differences in Testing, Hospital Admission, Clinical Presentation, and Drivers of Severe Outcomes From COVID-19

BACKGROUND

Males experience increased severity of illness and mortality from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) compared with females, but the mechanisms of male susceptibility are unclear.

METHODS

We performed a retrospective cohort analysis of SARS-CoV-2 testing and admission data at 5 hospitals in the Maryland/Washington DC area. Using age-stratified logistic regression models, we quantified the impact of male sex on the risk of the composite outcome of severe disease or death (World Health Organization score 5-8) and tested the impact of demographics, comorbidities, health behaviors, and laboratory inflammatory markers on the sex effect.

RESULTS

Among 213 175 SARS-CoV-2 tests, despite similar positivity rates, males in age strata between 18 and 74 years were more frequently hospitalized. For the 2626 hospitalized individuals, clinical inflammatory markers (interleukin-6, C-reactive protein, ferritin, absolute lymphocyte count, and neutrophil:lymphocyte ratio) were more favorable for females than males (P < .001). Among 18-49-year-olds, male sex carried a higher risk of severe outcomes, both early (odds ratio [OR], 3.01; 95% CI, 1.75 to 5.18) and at peak illness during hospitalization (OR, 2.58; 95% CI, 1.78 to 3.74). Despite multiple differences in demographics, presentation features, comorbidities, and health behaviors, these variables did not change the association of male sex with severe disease. Only clinical inflammatory marker values modified the sex effect, reducing the OR for severe outcomes in males aged 18-49 years to 1.81 (95% CI, 1.00 to 3.26) early and 1.39 (95% CI, 0.93 to 2.08) at peak illness.

CONCLUSIONS

Higher inflammatory laboratory test values were associated with increased risk of severe coronavirus disease 2019 for males. A sex-specific inflammatory response to SARS-CoV-2 infection may underlie the sex differences in outcomes.

DAMPening COVID-19 Severity by Attenuating Danger Signals

COVID-19 might lead to multi-organ failure and, in some cases, to death. The COVID-19 severity is associated with a “cytokine storm.” Danger-associated molecular patterns (DAMPs) are proinflammatory molecules that can activate pattern recognition receptors, such as toll-like receptors (TLRs). DAMPs and TLRs have not received much attention in COVID-19 but can explain some of the gender-, weight- and age-dependent effects. In females and males, TLRs are differentially expressed, likely contributing to higher COVID-19 severity in males. DAMPs and cytokines associated with COVID-19 mortality are elevated in obese and elderly individuals, which might explain the higher risk for severer COVID-19 in these groups. Adenosine signaling inhibits the TLR/NF-κB pathway and, through this, decreases inflammation and DAMPs’ effects. As vaccines will not be effective in all susceptible individuals and as new vaccine-resistant SARS-CoV-2 mutants might develop, it remains mandatory to find means to dampen COVID-19 disease severity, especially in high-risk groups. We propose that the regulation of DAMPs via adenosine signaling enhancement might be an effective way to lower the severity of COVID-19 and prevent multiple organ failure in the absence of severe side effects.

Sex Differences in Immunity to Viral Infections

The ongoing COVID-19 pandemic has increased awareness about sex-specific differences in immunity and outcomes following SARS-CoV-2 infection. Strong evidence of a male bias in COVID-19 disease severity is hypothesized to be mediated by sex differential immune responses against SARS-CoV-2. This hypothesis is based on data from other viral infections, including influenza viruses, HIV, hepatitis viruses, and others that have demonstrated sex-specific immunity to viral infections. Although males are more susceptible to most viral infections, females possess immunological features that render them more vulnerable to distinct immune-related disease outcomes. Both sex chromosome complement and related genes as well as sex steroids play important roles in mediating the development of sex differences in immunity to viral infections.

Characteristics and outcome of COVID-19 cases in Saudi Arabia: Review of six-months of data (March-August 2020)

Background

This study presents the demographic, epidemiological, and clinical characteristics of Coronavirus Disease 2019 (COVID-19) in Saudi Arabia (KSA). It identifies the important predictors of the disease prognosis.

Methods

The study reviewed and analysed a sample of 307,010 confirmed symptomatic COVID-19 cases, between March and August 2020, available in the health electronic surveillance system (HESN) of the Ministry of Health of KSA. Descriptive and univariate analyses were conducted.

Results

The overall estimated prevalence of symptomatic COVID-19 cases in KSA between March and August 2020 was 6.1% . The estimated incidence proportion was 879.7 per 100,000 population. The overall case fatality ratio was 2.0%. Males represented 63.9% , with a mean age of 35.1 ± 16.6 years. Young adults (16-39 years) were the most affected ages (53.3%). Fever (90.5%) with a mean body temperature of 37.4 ± 2.0 Celsius, cough (90%), and sore throat (77.4%) were the most prevalent symptoms. A history of contact with a confirmed COVID-19 case was reported in 98.8% of patients.Males (2.1%) and elderly cases aged 65-99 years (25.6%) had the highest association with mortality (p < .001). Among the clinical characteristics investigated, low oxygen saturation (SpO₂ ≤ 93%) had the highest association with hospital admission (50.8%) and mortality (19.1%) (p < .001). Cases with cardiovascular diseases (28.6%) and malignancy (28%) demonstrated the highest associations with mortality compared to other underlying diseases (p < .001).

Conclusions

In KSA, the prevalent symptoms of COVID-19 are fever, cough, and sore throat. Makkah and Almadinah regions are significantly associated with highest burden of mortality. The low level of oxygen saturation, high fever, old age, and underlying cardiovascular disease are the most important predictors for prognosis.

Immunity, Sex Hormones, and Environmental Factors as Determinants of COVID-19 Disparity in Women

The current coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2), has resulted in a major global pandemic, causing extreme morbidity and mortality. Few studies appear to suggest a significant impact of gender in morbidity and mortality, where men are reported at a higher risk than women. The infectivity, transmissibility, and varying degree of disease manifestation (mild, modest, and severe) in population studies reinforce the importance of a number of genetic and epigenetic factors, in the context of immune response and gender. The present review dwells on several contributing factors such as a stronger innate immune response, estrogen, angiotensin-converting enzyme 2 gene, and microbiota, which impart greater resistance to the SARS-CoV-2 infection and disease progression in women. In addition, the underlying importance of associated microbiota and certain environmental factors in gender-based disparity pertaining to the mortality and morbidity due to COVID-19 in women has also been addressed.

Repurposing the estrogen receptor modulator raloxifene to treat SARS-CoV-2 infection

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) necessitates strategies to identify prophylactic and therapeutic drug candidates to enter rapid clinical development. This is particularly true, given the uncertainty about the endurance of the immune memory induced by both previous infections or vaccines, and given the fact that the eradication of SARS-CoV-2 might be challenging to reach, given the attack rate of the virus, which would require unusually high protection by a vaccine. Here, we show how raloxifene, a selective estrogen receptor modulator with anti-inflammatory and antiviral properties, emerges as an attractive candidate entering clinical trials to test its efficacy in early-stage treatment COVID-19 patients.

COVID-19 pandemic: insights into molecular mechanisms leading to sex-based differences in patient outcomes

Recent epidemiological studies analysing sex-disaggregated patient data of coronavirus disease 2019 (COVID-19) across the world revealed a distinct sex bias in the disease morbidity as well as the mortality - both being higher for the men. Similar antecedents have been known for the previous viral infections, including from coronaviruses, such as severe acute respiratory syndrome (SARS) and middle-east respiratory syndrome (MERS). A sound understanding of molecular mechanisms leading to the biological sex bias in the survival outcomes of the patients in relation to COVID-19 will act as an essential requisite for developing a sex-differentiated approach for therapeutic management of this disease. Recent studies which have explored molecular mechanism(s) behind sex-based differences in COVID-19 pathogenesis are scarce; however, existing evidence, for other respiratory viral infections, viz. SARS, MERS and influenza, provides important clues in this regard. In attempt to consolidate the available knowledge on this issue, we conducted a systematic review of the existing empirical knowledge and recent experimental studies following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The qualitative analysis of the collected data unravelled multiple molecular mechanisms, such as evolutionary and genetic/epigenetic factors, sex-linkage of viral host cell entry receptor and immune response genes, sex hormone and gut microbiome-mediated immune-modulation, as the possible key reasons for the sex-based differences in patient outcomes in COVID-19.

Better prognosis in females with severe COVID-19 pneumonia: possible role of inflammation as potential mediator

OBJECTIVES

Sex differences in COVID-19 severity and mortality have been described. Key aims of this analysis were to compare the risk of invasive mechanical ventilation (IMV) and mortality by sex and to explore whether variation in specific biomarkers could mediate this difference.

METHODS

This was a retrospective, observational cohort study among patients with severe COVID-19 pneumonia. A survival analysis was conducted to compare time to the composite endpoint of IMV or death according to sex. Interaction was formally tested to compare the risk difference by sex in sub-populations. Mediation analysis with a binary endpoint IMV or death (yes/no) by day 28 of follow-up for a number of inflammation/coagulation biomarkers in the context of counterfactual prediction was also conducted.

RESULTS

Among 415 patients, 134 were females (32%) and 281 males (67%), median age 66 years (IQR 54-77). At admission, females showed a significantly less severe clinical and respiratory profiles with a higher PaO2/FiO2 (254 mmHg vs. 191 mmHg; p 0.023). By 28 days from admission, 49.2% (95% CI 39.6-58.9%) of males vs. 31.7% (17.9-45.4%) of females underwent IMV or death (log-rank p < 0.0001) and this amounted to a difference in terms of HR of 0.40 (0.26-0.63, p 0.0001). The area under the curve in C-reactive protein (CRP) over the study period appeared to explain 85% of this difference in risk by sex.

DISCUSSION

Our analysis confirms a difference in the risk of COVID-19 clinical progression by sex and provides a hypothesis for potential mechanisms leading to this. Specifically, CRP showed a predominant role to mediate the difference in risk by sex.

Sex hormones, autoimmunity and gender disparity in COVID-19

The Coronavirus disease 2019 (COVID-19) pandemic has majorly contributed to massive and widespread mortality. Epidemiological data strongly indicates a sex-based disparity in COVID-19 clinical outcomes, with women having lower infection and hospitalisation rates, coupled with better prognosis and lesser mortality. This disparity may be explained by several mechanisms including differences in innate and adaptive immune responses, genetic factors, and an interplay between sex hormones and immune effectors, as well as gender-specific behaviour differences. These pathways, particularly the immunological divergence in response to viral infection, could potentially influence not only COVID-19 pathogenesis and disease course, but also the response to antiviral drugs and vaccines. Furthermore, factors that confer a protective advantage against COVID-19 may be exploited to develop therapeutic strategies to improve clinical outcomes in COVID-19.

[COVID-19 from the perspective of a gynecological endocrinologist]

Die von SARS-CoV‑2 („severe acute respiratory syndrome coronavirus 2“) ausgelöste infektiöse Atemwegserkrankung COVID-19 („coronavirus disease 2019“) weist in ihrem Verlauf und Schweregrad eine deutliche Abhängigkeit vom Geschlecht der Erkrankten auf. So ist die Inzidenzrate bei Frauen höher als bei Männern, während bei Männern schwere Verlaufsformen erheblich häufiger zu beobachten sind und die Mortalitätsrate bei ihnen signifikant höher ist. Allerdings unterscheiden sich wiederum prämenopausale und postmenopausale Frauen hinsichtlich des Verlaufs. Prämenopausale Frauen müssen seltener hospitalisiert werden und bedürfen seltener maschineller Beatmung. Postmenopausale Frauen, die eine Hormonersatztherapie erhalten, scheinen davon zu profitieren. Ergebnisse der Grundlagenforschung am Mausmodell zeigen, dass die weiblichen Sexualsteroide im Falle der Influenza den Entzündungsverlauf positiv beeinflussen bzw. im Falle von SARS-CoV‑2 die Empfänglichkeit gegenüber dem Virus herabsenken, während Androgene eine Erhöhung der Infektionsrate zur Folge haben. Dies gilt auch für Patientinnen mit polyzystischem Ovarsyndrom. Erste Ergebnisse von Therapiestudie mit Progesteron – wenngleich mit kleinen Patientenzahlen – weisen darauf hin, dass eine Therapie mit diesem Sexualsteroid sich positiv auf den Krankheitsverlauf bei betroffenen Männern auswirken kann. Allerdings zeigt auch die Verteilung der Komplikationen im Zusammenhang mit der Impfung gegen COVID-19 eine deutliche Geschlechterdifferenz, hier mit einem höheren relativen Risiko für jüngere Frauen.

Sex and age bias viral burden and interferon responses during SARS-CoV-2 infection in ferrets

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) hospitalizations and deaths disportionally affect males and older ages. Here we investigated the impact of male sex and age comparing sex-matched or age-matched ferrets infected with SARS-CoV-2. Differences in temperature regulation was identified for male ferrets which was accompanied by prolonged viral replication in the upper respiratory tract after infection. Gene expression analysis of the nasal turbinates indicated that 1-year-old female ferrets had significant increases in interferon response genes post infection which were delayed in males. These results provide insight into COVID-19 and suggests that older males may play a role in viral transmission due to decreased antiviral responses.

Risk Factors and Clinical Phenotypes Associated with Severity in Patients with COVID-19 in Northeast Mexico

Objective: The aim of this study is to describe the main clinical phenotypes, laboratory findings, and severity of coronavirus disease 2019 (COVID-19) in patients hospitalized at the High Specialty Medical Unit # 71 of the Mexican Social Security Institute. Methods: Prospective observational cohort study with a total of 105 patients hospitalized with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection at the High Specialty Medical Unit # 71 (Torreón, Coahuila, Mexico), from May 15th to August 15th, 2020. The cases were confirmed to be COVID-19 positive through an RT-qPCR test. Clinical phenotypes and laboratory tests were evaluated to determine the degree of severity of the disease and the most frequent comorbidities. Results: The clinical characteristics of a total of 105 hospitalized patients (47 females and 58 males; median age being 52 years) with confirmed COVID-19 diagnoses were studied. The severity of the disease was classified as moderate grade (62.7%), severe grade (21.5%), and critical grade (15.6%). Among the most frequent underlying pathologies coexisted overweight (n = 75, 78.12%), obesity (n = 21, 21.87%), diabetes (n = 10, 9.52%), and hypertension (n = 6, 5.71%), some of these patients present more than one pathology. This association was found with diabetes (odds ratio [OR]: 1.42; 95% confidence interval [CI]: 1.23-1.97; p = 0.021) and high levels of D-dimer (OR: 1.01; 95% CI: 1.00-1.08; p = 0.001). Conclusion: In this retrospective cohort study of patients with COVID-19 from a specialty hospital in the northeast region of Mexico, it was observed that clinical phenotypes and D-dimer elevation were compatible with an inflammatory state by degree of severity; it was found that the hospitalized patients with underlying chronic medical conditions such as diabetes and elevated D-dimer levels were significantly associated with increased mortality from COVID-19. Age and sex (males) were two factors highly associated with mortality.

Disease state prediction for 2019 novel coronavirus (COVID-19) pneumonia using CT manifestations and body temperature dynamic analysis: A SQUIRE-compliant study

2019 Novel Coronavirus (COVID-19) is a new acute infectious disease of respiratory system, posed a great threat to human health because of its strong infectivity and rapid progress. This study aimed to assess the severity of COVID-19 Pneumonia by analyzing the change of CT manifestations and body temperature.This retrospective review included 22 patients with COVID-19 pneumonia. The imaging manifestations and clinical features were observed and evaluated.Most of the infected patients were men (13/22, 59%). Fever (>38°C) (17/22, 77%) and cough (6/22, 27%) were the main symptoms. Leukocytes count decreased in 23% of patients and lymphocyte decreased in 41%. Twenty-one patients with pneumonia had abnormal findings on chest CT. The special CT manifestations were observed at the first CT examination when the lesions progressed, including a single ground glass nodule with uneven density, multiple ground glass opacities distributed in subpleural, and the ground glass opacities confined in superior lobe. The special CT manifestations were observed at the first CT examination when the lesions resolved, including ground glass opacities with homogeneous density. The lesion involved in the bilateral lungs and the absorption of the lesions mainly occurred in bilateral inferior lobes. Three patients had normalized body temperature increased more than 1°C within 1 to 2 days after admission. Ten patients fluctuated more than 1°C within 1 to 7 days after admission and the second CT scans showed the disease was at the progressive stage.Dynamic analysis of CT manifestations and body temperature have the potential to predict the severity of COVID-19 pneumonia.

Sex-based clinical and immunological differences in COVID-19

BACKGROUND

Males and females differ in their immunological responses to foreign pathogens. However, most of the current COVID-19 clinical practices and trials do not take the sex factor into consideration.

METHODS

We performed a sex-based comparative analysis for the clinical outcomes, peripheral immune cells, and severe acute respiratory syndrome coronavirus (SARS-CoV-2) specific antibody levels of 1558 males and 1499 females COVID-19 patients from a single center. The lymphocyte subgroups were measured by Flow cytometry. The total antibody, Spike protein (S)-, receptor binding domain (RBD)-, and nucleoprotein (N)- specific IgM and IgG levels were measured by chemiluminescence.

RESULTS

We found that male patients had approximately two-fold rates of ICU admission (4.7% vs. 2.7% in males and females, respectively, P = 0.005) and mortality (3% vs. 1.4%, in males and females, respectively, P = 0.004) than female patients. Survival analysis revealed that the male sex is an independent risk factor for death from COVID-19 (adjusted hazard ratio [HR] = 2.22, 95% confidence interval [CI]: 1.3-3.6, P = 0.003). The level of inflammatory cytokines in peripheral blood was higher in males during hospitalization. The renal (102/1588 [6.5%] vs. 63/1499 [4.2%], in males and females, respectively, P = 0.002) and hepatic abnormality (650/1588 [40.9%] vs. 475/1499 [31.7%], P = 0.003) were more common in male patients than in female patients. By analyzing dynamic changes of lymphocyte subsets after symptom onset, we found that the percentage of CD19+ B cells and CD4+ T cells was generally higher in female patients during the disease course of COVID-19. Notably, the protective RBD-specific IgG against SARS-CoV-2 sharply increased and reached a peak in the fourth week after symptom onset in female patients, while gradually increased and reached a peak in the seventh week after symptom onset in male patients.

CONCLUSIONS

Males had an unfavorable prognosis, higher inflammation, a lower percentage of lymphocytes, and indolent antibody responses during SARS-CoV-2 infection and recovery. Early medical intervention and close monitoring are important, especially for male COVID-19 patients.

Innate lymphoid cells and disease tolerance in SARS-CoV-2 infection

Risk of severe COVID-19 increases with age, is greater in males, and is associated with lymphopenia, but not with higher burden of SARS-CoV-2. It is unknown whether effects of age and sex on abundance of specific lymphoid subsets explain these correlations. This study found that the abundance of innate lymphoid cells (ILCs) decreases more than 7-fold over the human lifespan — T cell subsets decrease less than 2-fold — and is lower in males than in females. After accounting for effects of age and sex, ILCs, but not T cells, were lower in adults hospitalized with COVID-19, independent of lymphopenia. Among SARS-CoV-2-infected adults, the abundance of ILCs, but not of T cells, correlated inversely with odds and duration of hospitalization, and with severity of inflammation. ILCs were also uniquely decreased in pediatric COVID-19 and the numbers of these cells did not recover during follow-up. In contrast, children with MIS-C had depletion of both ILCs and T cells, and both cell types increased during follow-up. In both pediatric COVID-19 and MIS-C, ILC abundance correlated inversely with inflammation. Blood ILC mRNA and phenotype tracked closely with ILCs from lung. Importantly, blood ILCs produced amphiregulin, a protein implicated in disease tolerance and tissue homeostasis, and the percentage of amphiregulin-producing ILCs was higher in females than in males. These results suggest that, by promoting disease tolerance, homeostatic ILCs decrease morbidity and mortality associated with SARS-CoV-2 infection, and that lower ILC abundance accounts for increased COVID-19 severity with age and in males.

Neutrophils in respiratory viral infections

Viral respiratory infections are a common cause of severe disease, especially in infants, people who are immunocompromised, and in the elderly. Neutrophils, an important innate immune cell, infiltrate the lungs rapidly after an inflammatory insult. The most well-characterized effector mechanisms by which neutrophils contribute to host defense are largely extracellular and the involvement of neutrophils in protection from numerous bacterial and fungal infections is well established. However, the role of neutrophils in responses to viruses, which replicate intracellularly, has been less studied. It remains unclear whether and, by which underlying immunological mechanisms, neutrophils contribute to viral control or confer protection against an intracellular pathogen. Furthermore, neutrophils need to be tightly regulated to avoid bystander damage to host tissues. This is especially relevant in the lung where damage to delicate alveolar structures can compromise gas exchange with life-threatening consequences. It is inherently less clear how neutrophils can contribute to host immunity to viruses without causing immunopathology and/or exacerbating disease severity. In this review, we summarize and discuss the current understanding of how neutrophils in the lung direct immune responses to viruses, control viral replication and spread, and cause pathology during respiratory viral infections.

SARS-CoV-2 effects in the genitourinary system and prospects of sex hormone therapy

OBJECT

Corona virus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which leads to acute respiratory infection symptoms. SARS-CoV-2 infection is not always limited to the respiratory tract, and renal infection and dysfunction have been shown to be specific risk factors for death. In addition, COVID-19 has a higher incidence, severity and mortality in men than women. This disparity is due to biological rather than comorbid or behavioral sex differences. Because the male reproductive system is unique, the function of sex hormones in COVID-19 infection may explain the differences between males and females. Understanding these factors will provide appropriate prevention measures and adequate triage strategies and guide the drug discovery process.

METHODS

An electronic search was completed in PubMed, ARXIV, MEDRXIV and BIORXIV. The most relevant articles were systematically reviewed. In addition, single cell RNA sequencing analysis of tissue samples from human cell landscape was conducted.

RESULTS

The influence of SARS-CoV-2 on the urogenital system, the possibility of urinary tract transmission and the functions of sex hormones were discussed in this review.

CONCLUSION

Corona viruses can invade the genitourinary system, causing urological symptoms. Identifying the potential genitourinary organ impairments and protecting them from damage are necessary. Since sex hormones have potential as specific drugs, the gonadal hormones substitution therapy should be considered in both sexes in the COVID-19 pandemic.

ACE2-lentiviral transduction enables mouse SARS-CoV-2 infection and mapping of receptor interactions

SARS-CoV-2 uses the human ACE2 (hACE2) receptor for cell attachment and entry, with mouse ACE2 (mACE2) unable to support infection. Herein we describe an ACE2-lentivirus system and illustrate its utility for in vitro and in vivo SARS-CoV-2 infection models. Transduction of non-permissive cell lines with hACE2 imparted replication competence, and transduction with mACE2 containing N30D, N31K, F83Y and H353K substitutions, to match hACE2, rescued SARS-CoV-2 replication. Intrapulmonary hACE2-lentivirus transduction of C57BL/6J mice permitted significant virus replication in lung epithelium. RNA-Seq and histological analyses illustrated that this model involved an acute inflammatory disease followed by resolution and tissue repair, with a transcriptomic profile similar to that seen in COVID-19 patients. hACE2-lentivirus transduction of IFNAR-/- and IL-28RA-/- mouse lungs was used to illustrate that loss of type I or III interferon responses have no significant effect on virus replication. However, their importance in driving inflammatory responses was illustrated by RNA-Seq analyses. We also demonstrate the utility of the hACE2-lentivirus transduction system for vaccine evaluation in C57BL/6J mice. The ACE2-lentivirus system thus has broad application in SARS-CoV-2 research, providing a tool for both mutagenesis studies and mouse model development.

COVID-19 Gender Disparities and Mitigation Recommendations: A Narrative Review

The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19.

COVID-19 and the Endocrine System: A Comprehensive Review on the Theme

Background and aim. The review aimed to summarize advances in the topic of endocrine diseases and coronavirus disease 2019 (COVID-19). Methods. Scientific and institutional websites and databases were searched and data were collected and organized, when plausible, to angle the discussion toward the following clinical issues. (1) Are patients with COVID-19 at higher risk of developing acute or late-onset endocrine diseases or dysfunction? (2) May the underlying endocrine diseases or dysfunctions be considered risk factors for poor prognosis once the infection has occurred? (3) Are there defined strategies to manage endocrine diseases despite pandemic-related constraints? Herein, the authors considered only relevant and more frequently observed endocrine diseases and disorders related to the hypothalamic-pituitary region, thyroid and parathyroid glands, calcium-phosphorus homeostasis and osteoporosis, adrenal glands, and gonads. Main. Data highlight the basis of some pathophysiological mechanisms and anatomical alterations of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)-induced endocrine dysfunctions. Some conditions, such as adrenal insufficiency and cortisol excess, may be risk factors of worse clinical progression once the infection has occurred. These at-risk populations may require adequate education to avoid the SARS-CoV-2 infection and adequately manage medical therapy during the pandemic, even in emergencies. Endocrine disease management underwent a palpable restraint, especially procedures requiring obligate access to healthcare facilities for diagnostic and therapeutic purposes. Strategies of clinical triage to prioritize medical consultations, laboratory, instrumental evaluations, and digital telehealth solutions should be implemented to better deal with this probably long-term situation.

Comparison of two pandemics: H1N1 and SARS-CoV-2

OBJECTIVE

We aimed to compare the clinical, epidemiological, and prognostic features of the H1N1 pandemic in 2009 and the severe acute respiratory syndrome coronavirus 2 pandemic in 2020.

METHODS

This retrospective study involved subjects from seven centers that were admitted and found to be positive for H1N1 or COVID-19 real-time polymerase chain reaction test.

RESULTS

A total of 143 patients with H1N1 and 309 patients with COVID-19 were involved in the study. H1N1 patients were younger than COVID-19 ones. While 58.7% of H1N1 patients were female, 57.9% of COVID-19 patients were male. Complaints of fever, cough, sputum, sore throat, myalgia, weakness, headache, and shortness of breath in H1N1 patients were statistically higher than in COVID-19 ones. The duration of symptoms until H1N1 patients were admitted to the hospital was shorter than that for COVID-19 patients. Leukopenia was more common in COVID-19 patients. C-reactive protein levels were higher in COVID-19 patients, while lactate dehydrogenase levels were higher in H1N1 ones. The mortality rate was also higher in H1N1 cases.

CONCLUSIONS

The severe acute respiratory syndrome coronavirus 2 pandemic is a major public health problem that continues to affect the world with its high rate of contagion. In addition, no vaccines or a specific drug for the benefit of millions of people have been found yet. The H1N1 pandemic is an epidemic that affected the whole world about ten years ago and was prevented by the development of vaccines at a short period. Experience in the H1N1 pandemic may be the guide to prevent the COVID-19 pandemic from a worse end.

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.

Estrogen Receptor Modulators in Viral Infections Such as SARS-CoV-2: Therapeutic Consequences

COVID-19 is a pandemic respiratory disease caused by the SARS-CoV-2 coronavirus. The worldwide epidemiologic data showed higher mortality in males compared to females, suggesting a hypothesis about the protective effect of estrogens against severe disease progression with the ultimate end being patient's death. This article summarizes the current knowledge regarding the potential effect of estrogens and other modulators of estrogen receptors on COVID-19. While estrogen receptor activation shows complex effects on the patient's organism, such as an influence on the cardiovascular/pulmonary/immune system which includes lower production of cytokines responsible for the cytokine storm, the receptor-independent effects directly inhibits viral replication. Furthermore, it inhibits the interaction of IL-6 with its receptor complex. Interestingly, in addition to natural hormones, phytestrogens and even synthetic molecules are able to interact with the estrogen receptor and exhibit some anti-COVID-19 activity. From this point of view, estrogen receptor modulators have the potential to be included in the anti-COVID-19 therapeutic arsenal.

The role of sexual dimorphism in susceptibility to SARS-CoV-2 infection, disease severity, and mortality: facts, controversies and future perspectives

Former studies have revealed intersex variability in immune response to infectious diseases, including Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological surveillance of the ongoing pandemic has demonstrated a male vulnerability to morbidity and mortality, despite similar infection rates between the two sexes. Divergence in the frequency of comorbidities between males and females, differences in hormonal profile, chromosomal composition and gender behavior have all been proposed as potential causative factors. Data deriving from the immunization process indirectly support the existence of a sex-specific response to SARS-CoV-2, since females apparently produce higher numbers of antibodies while simultaneously exhibiting higher rates of side effects, indicating a stronger immune reactivity to the vaccine's elements. Interpreting intersex differences in immune response to SARS-CoV-2 could lead to a deeper understanding of the COVID-19 pathophysiology and enable healthcare professionals to conduct a more accurate patient risk assessment and better predict the clinical outcome of the disease. This narrative review aims to discuss the pathophysiological and behavioral basis of the disproportionate male morbidity and mortality observed in COVID-19, in the context of most research findings in the field.

Innate immunity, inflammation activation and heat-shock protein in COVID-19 pathogenesis

SARS-CoV-2-induced COVID-19 is a serious pandemic of the 21st century, which has caused a devastating loss of lives and a global economic catastrophe. A successful vaccine against SARS-CoV-2 has suffered a delay due to lack of substantial knowledge about its mechanisms of action. Understanding the innate immune system against SARS-CoV-2 and the role of heat shock proteins' (HSP) inhibiting and resolution of inflammatory pathways may provide information to the low SARS-CoV-2 mortality rates in Africa. In addition, bats being a host to different viruses, including SARS-CoV-2 possess a well specialized IFN-innate antiviral inflammatory response, showing no signs of disease or pro-inflammatory cytokine storm. We discuss the molecular pathways in COVID-19 with a focus on innate immunity, inflammation, HSP responses, and suggest appropriate candidates for therapeutic targets and The contribution of the innate immune system to the efficacy of mRNA or vector based Corona immunizations.

Mucosal-associated invariant T cell responses differ by sex in COVID-19

BACKGROUND

Sexual dimorphisms in immune responses contribute to coronavirus disease 2019 (COVID-19) outcomes, but the mechanisms governing this disparity remain incompletely understood.

METHODS

We carried out sex-balanced sampling of peripheral blood mononuclear cells from hospitalized and non-hospitalized individuals with confirmed COVID-19, uninfected close contacts, and healthy control individuals for 36-color flow cytometry and single-cell RNA sequencing.

FINDINGS

Our results revealed a pronounced reduction of circulating mucosal-associated invariant T (MAIT) cells in infected females. Integration of published COVID-19 airway tissue datasets suggests that this reduction represented a major wave of MAIT cell extravasation during early infection in females. Moreover, MAIT cells from females possessed an immunologically active gene signature, whereas cells from males were pro-apoptotic.

CONCLUSIONS

Our findings uncover a female-specific protective MAIT cell profile, potentially shedding light on reduced COVID-19 susceptibility in females.

FUNDING

This work was supported by NIH/NIAID (U01AI066569 and UM1AI104681), the Defense Advanced Projects Agency (DARPA; N66001-09-C-2082 and HR0011-17-2-0069), the Veterans Affairs Health System, and Virology Quality Assurance (VQA; 75N93019C00015). The content is solely the responsibility of the authors and does not necessarily represent the official view of the National Institutes of Health. COVID-19 samples were processed under Biosafety level 2 (BSL-2) with aerosol management enhancement or BSL-3 in the Duke Regional Biocontainment Laboratory, which received partial support for construction from NIH/NIAID (UC6AI058607).

Gender Specific Differences in Disease Susceptibility: The Role of Epigenetics

Many complex traits or diseases, such as infectious and autoimmune diseases, cancer, xenobiotics exposure, neurodevelopmental and neurodegenerative diseases, as well as the outcome of vaccination, show a differential susceptibility between males and females. In general, the female immune system responds more efficiently to pathogens. However, this can lead to over-reactive immune responses, which may explain the higher presence of autoimmune diseases in women, but also potentially the more adverse effects of vaccination in females compared with in males. Many clinical and epidemiological studies reported, for the SARS-CoV-2 infection, a gender-biased differential response; however, the majority of reports dealt with a comparable morbidity, with males, however, showing higher COVID-19 adverse outcomes. Although gender differences in immune responses have been studied predominantly within the context of sex hormone effects, some other mechanisms have been invoked: cellular mosaicism, skewed X chromosome inactivation, genes escaping X chromosome inactivation, and miRNAs encoded on the X chromosome. The hormonal hypothesis as well as other mechanisms will be examined and discussed in the light of the most recent epigenetic findings in the field, as the concept that epigenetics is the unifying mechanism in explaining gender-specific differences is increasingly emerging.

Sex Differences in Respiratory Viral Pathogenesis and Treatments

Biological sex affects the outcome of diverse respiratory viral infections. The pathogenesis of respiratory infections caused by viruses ranging from respiratory syncytial virus to influenza viruses and severe acute respiratory syndrome coronavirus 2 differs between the sexes across the life course. Generally, males are more susceptible to severe outcomes from respiratory viral infections at younger and older ages. During reproductive years (i.e., after puberty and prior to menopause), females are often at greater risk than males for severe outcomes. Pregnancy and biological sex affect the pathogenesis of respiratory viral infections. In addition to sex differences in the pathogenesis of disease, there are consistent sex differences in responses to treatments, with females often developing greater immune responses but experiencing more adverse reactions than males. Animal models provide mechanistic insights into the causes of sex differences in respiratory virus pathogenesis and treatment outcomes, where available. Expected final online publication date for the Annual Review of Virology, Volume 8 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Could Nanotheranostics be the Answer to the Coronavirus Crisis?

The COVID-19 pandemic is expanding worldwide. This pandemic associated with COVID-19 placed the spotlight on how bacterial (e.g., methicillin-resistant Staphylococcus aureus) co-infections may impact responses to coronavirus. In this review the ways in which nanoparticles can contain and rapidly diagnose COVID-19 under the umbrella of nanotheranostics (i.e., smart, single agents combining nanodiagnostics and nanotherapeutics) are elaborated. The present work provides new insights into the promising incorporation of antiviral nanotheranostics into nanostructured materials, including electrospun fibers with tailored pore sizes and hydrophobicity, namely "superhydrophobic self-disinfecting electrospun facemasks/fabrics (SSEF)." SSEFs are proposed as smart alternatives to address the drawbacks of N95 respirators. The challenges of coronavirus containment are underscored, literature is reviewed, and "top-five suggestions" for containing COVID-19 are offered, including: i) preventive appraisals-avoiding needless hospital admission and practicing frequent hand washing (from 20 to 60 s). ii) Diagnostics-highly recommending nanodiagnostics, detecting COVID-19 within 10 min. iii) Therapeutics-expanding nanotherapeutics to treat COVID-19 and bacterial co-infections after safety assessments and clinical trials. iv) Multipronged and multinational, including China, collaborative appraisals. v) Humanitarian compassion to traverse this pandemic in a united way.

Upper Respiratory Tract Co-detection of Human Endemic Coronaviruses and High-density Pneumococcus Associated With Increased Severity Among HIV-Uninfected Children Under 5 Years Old in the PERCH Study

BACKGROUND

Severity of viral respiratory illnesses can be increased with bacterial coinfection and can vary by sex, but influence of coinfection and sex on human endemic coronavirus (CoV) species, which generally cause mild to moderate respiratory illness, is unknown. We evaluated CoV and pneumococcal co-detection by sex in childhood pneumonia.

METHODS

In the 2011-2014 Pneumonia Etiology Research for Child Health study, nasopharyngeal and oropharyngeal (NP/OP) swabs and other samples were collected from 3981 children <5 years hospitalized with severe or very severe pneumonia in 7 countries. Severity by NP/OP detection status of CoV (NL63, 229E, OC43 or HKU1) and high-density (≥6.9 log10 copies/mL) pneumococcus (HDSpn) by real-time polymerase chain reaction was assessed by sex using logistic regression adjusted for age and site.

RESULTS

There were 43 (1.1%) CoV+/HDSpn+, 247 CoV+/HDSpn-, 449 CoV-/HDSpn+ and 3149 CoV-/HDSpn- cases with no significant difference in co-detection frequency by sex (range 51.2%-64.0% male, P = 0.06). More CoV+/HDSpn+ pneumonia was very severe compared with other groups for both males (13/22, 59.1% versus range 29.1%-34.7%, P = 0.04) and females (10/21, 47.6% versus 32.5%-43.5%, P = 0.009), but only male CoV+/HDSpn+ required supplemental oxygen more frequently (45.0% versus 20.6%-28.6%, P < 0.001) and had higher mortality (35.0% versus 5.3%-7.1%, P = 0.004) than other groups. For females with CoV+/HDSpn+, supplemental oxygen was 25.0% versus 24.8%-33.3% (P = 0.58) and mortality was 10.0% versus 9.2%-12.9% (P = 0.69).

CONCLUSIONS

Co-detection of endemic CoV and HDSpn was rare in children hospitalized with pneumonia, but associated with higher severity and mortality in males. Findings may warrant investigation of differences in severity by sex with co-detection of HDSpn and SARS-CoV-2.

COVID-19 pandemic: what about the gonads?

The novel SARS-CoV-2 has spread to virtually all countries of the world infecting millions of people, the medical burden of this disease obviously being enormous. The gonads of both sexes are among the organs that may be affected by COVID-19 and/or may affect the severity of the disease. The clinical spectrum of SARS-CoV-2 infection clearly differs between genders. The current evidence indicates that the underlying mechanism of such an interaction could be associated with genetic, hormonal, and immunological differences, as well as with gender differences in such habits as smoking and alcohol use. On the other hand, there are controversies as to how and to what extent the gonads could be affected by COVID-19, possibly impacting upon sex steroids, fertility, and other functions. This review underlines the possible mechanisms that could clarify these questions concerning COVID-19 and the gonads. In addition, reference is made to potential new treatment modalities presently under investigation, these supported by accumulating data published in the recent literature.

Analysis of COVID-19 pandemics in Kazakhstan

Background: This study aimed to analyze the demographic and epidemiological features of identified COVID-19 cases in Kazakhstan.

Study design: A cross-sectional study.

Methods: This cross-sectional study aimed to analyze COVID-19 cases (n=5116) collected from March 13 to June 6, 2020, in Kazakhstan. The data were obtained from a state official medical electronic database. The study investigated the geographic and demographic data of patients as well as the association of COVID-19 cases with gender and age. The prevalence of symptoms, the presence of comorbidities, complications, and COVID-19 mortality were determined for all patients.

Results: The mean ±SD age of the patients in this study was 34.8 ±17.6 years, and the majority (55.7%) of COVID-19 cases were male and residents of cities (79.6%). In total, 80% of the cases had the asymptomatic/mild form of the disease. Cough (20.8 %) and sore throat (17.1%) were the most common symptoms among patients, and pneumonia was diagnosed in 1 out of 5 cases. Acute respiratory distress syndrome (ARDS) was recorded in 1.2% of the patients. The fatality rate was 1% in the study population and lethality was 2.6 times higher in males compared to females. Each additional year in age increased the probability of COVID-19 infection by 1.06 times. The presence of cardiovascular, diabetes, respiratory, and kidney diseases affected the rate of mortality (P<0.05).

Conclusions: The results demonstrated a high proportion (40%) of the asymptomatic type of coronavirus infection in the Kazakhstan population. The severity of COVID-19 symptoms and lethality were directly related to the age of patients and the presence of comorbidities.

Sex-Disaggregated Data on Clinical Characteristics and Outcomes of Hospitalized Patients With COVID-19: A Retrospective Study

Background

Sex and gender are crucial variables in coronavirus disease 2019 (COVID-19). We sought to provide information on differences in clinical characteristics and outcomes between male and female patients and to explore the effect of estrogen in disease outcomes in patients with COVID-19.

Method

In this retrospective, multi-center study, we included all confirmed cases of COVID-19 admitted to four hospitals in Hubei province, China from Dec 31, 2019 to Mar 31, 2020. Cases were confirmed by real-time RT-PCR and were analyzed for demographic, clinical, laboratory and radiographic parameters. Random-effect logistic regression analysis was used to assess the association between sex and disease outcomes.

Results

A total of 2501 hospitalized patients with COVID-19 were included in the present study. The clinical manifestations of male and female patients with COVID-19 were similar, while male patients have more comorbidities than female patients. In terms of laboratory findings, compared with female patients, male patients were more likely to have lymphopenia, thrombocytopenia, inflammatory response, hypoproteinemia, and extrapulmonary organ damage. Random-effect logistic regression analysis indicated that male patients were more likely to progress into severe type, and prone to ARDS, secondary bacterial infection, and death than females. However, there was no significant difference in disease outcomes between postmenopausal and premenopausal females after propensity score matching (PSM) by age.

Conclusions

Male patients, especially those age-matched with postmenopausal females, are more likely to have poor outcomes. Sex-specific differences in clinical characteristics and outcomes do exist in patients with COVID-19, but estrogen may not be the primary cause. Further studies are needed to explore the causes of the differences in disease outcomes between the sexes.

The understanding of the immunopathology in COVID-19 infection

Coronaviruses belonging to the Coronaviridae family are single-stranded RNA viruses. The entry of SARS-CoV-2 is accomplished via ACE-2 receptors. SARS-CoV-2 infection coactivates both innate and adaptive immune responses. Although SARS-CoV-2 stimulates antibody production with a typical pattern of IgM/IgG, cellular immunity is also impaired. In severe cases, low CD4 + and CD8 + T cell counts are associated with impaired immune functions, and high neutrophil/lymphocyte ratios accompanying low lymphocyte subsets have been demonstrated. Recently, high IFN -α/γ ratios with impaired T cell responses, and increased IL-1, IL-6, TNF-α, MCP-1, IP-10, IL-4, IL-10 have been reported in COVID-19 infection. Increased proinflammatory cytokines and chemokines in patients with severe COVID-19 may cause the suppression of CD4 + and CD8 + T cells and regulatory T cells, causing excessive inflammatory responses and fatal cytokine storm with tissue and organ damage. Consequently, novel therapeutics to be developed against host immune system, including blockade of cytokines (IL-6, IL-1, IFN) themselves, their receptors or signaling pathways- JAK inhibitors- could be effective as potential therapeutics.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

Sex Disparity in the Effect of Obesity in Hospitalized COVID-19 Patients: A Retrospective Cohort Study From the New York City Metropolitan Area

INTRODUCTION

 Obesity has been recognized as a risk factor for poor outcomes in coronavirus disease 2019 (COVID-19) illness. We analyzed the impact of patient characteristics including obesity on hospital mortality and specifically analyzed the effect of obesity by body mass index (BMI) class and by sex.

METHODS

 This retrospective case series included adult patients consecutively hospitalized with confirmed COVID-19 illness between March 12, 2020 and May 13, 2020, at a teaching hospital in the New York City (NYC) metropolitan area. Data were manually extracted from electronic health records by the authors and included demographics, comorbidities, laboratory parameters, and outcomes (hospital mortality or discharge). We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death.

RESULTS

 Some 348 patients were included in this study, of whom 207 were discharged and 141 died in the hospital. Multivariable regression showed increasing odds of in-hospital death with older age and excess weight. Interestingly obesity increased mortality in women [odds ratio (OR) 4.4, confidence interval (CI) (1.4-13.5) p=0.01] but not among men [OR 1.4, CI (0.5-3.6) p=0.5]. Among women, the effect of excess weight on mortality was seen in a "dose-effect" fashion, with increasingly higher odds of mortality from progressively worsening obesity (OR ranging between 2.7 and 6.9). Out of all the comorbidities, only obesity positively correlated with peak levels of C-reactive protein (CRP).

CONCLUSION

 Advancing age is a risk factor for in-hospital death during COVID-19 illness. Obese women could be at a higher risk for mortality due to COVID-19 and should take extra precautions to prevent contamination by social distancing and other measures. Immunomodulators may be more effective in obese women affected by COVID-19. Further studies are needed to help elucidate this association.

COVID-19 in Africa: an ovarian victory?

Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mainly attacks the respiratory system and is characterized by pneumonia, cytokine storm, coagulation disorders and severe immune downregulation. Although public health experts predicted worst outcomes in Africa, the incidence, hospitalization and mortality rates have been lower in Africa compared to other continents. Interestingly, lower incidence and mortality rates have been observed in women from Africa compared to their cohorts from other continents. Also, in the US non-Hispanic Black females have lower COVID-19 and death rates compared to their white counterparts. It's unclear why this significant difference exists; however, the ovarian function, genetics and immunological statuses could play a major role. Women of African descent have elevated levels of estrogen compared with Caucasians hence we anticipate that estrogen might offer some protection against the SARS-CoV-2 infections. The racial differences in lifestyle, age and inaccessibility to contraceptive usage might also play a role. Here, we provide insight on how the high levels of estrogen in African women might contribute to the lower cases and fatalities in Africa. Specifically, estrogen might offer protection against COVID-19 by suppressing hyper-production of cytokines, promoting anti-inflammatory cytokines, stimulating antibody production and suppressing endoplasmic reticulum (ER) stress. This will as well provide useful information on how future pandemics could be managed using Africa as a case study.

Characteristics and impact of cardiovascular comorbidities on coronavirus disease 2019 in women: A multicentre cohort study

Background

Although women account for up to half of patients hospitalized for coronavirus disease 2019 (COVID-19), no specific data have been reported in this population.

Aims

To assess the burden and impact of cardiovascular comorbidities in women with COVID-19.

Methods

All consecutive patients hospitalized for COVID-19 across 24 hospitals from 26 February to 20 April 2020 were included. The primary composite outcome was transfer to an intensive care unit or in-hospital death.

Results

Among 2878 patients, 1212 (42.1%) were women. Women were older (68.3 ± 18.0 vs. 65.4 ± 16.0 years; P < 0.001), but had less prevalent cardiovascular comorbidities than men. Among women, 276 (22.8%) experienced the primary outcome, including 161 (13.3%) transfers to an intensive care unit and 115 (9.5%) deaths without transfer to intensive care unit. The rate of in-hospital death or transfer to an intensive care unit was lower in women versus men (crude hazard ratio [HR]: 0.62, 95% confidence interval [CI]: 0.53–0.72). Age (adjusted HR: 1.05 per 5-year increase, 95% CI: 1.01–1.10), body mass index (adjusted HR: 1.06 per 2-unit increase, 95% CI: 1.02–1.10), chronic kidney disease (adjusted HR: 1.57, 95% CI: 1.11–2.22) and heart failure (adjusted HR: 1.52, 95% CI: 1.04–2.22) were independently associated with the primary outcome in women. Elevated B-type natriuretic peptide/N-terminal prohormone of B-type natriuretic peptide (adjusted HR: 2.41, 95% CI: 1.70–3.44) and troponin (adjusted HR: 2.00, 95% CI: 1.39–2.88) concentrations at admission were also associated with the primary outcome, even in women free of previous coronary artery disease or heart failure.

Conclusions

Although female sex was associated with a lower risk of transfer to an intensive care unit or in-hospital death, COVID-19 remained associated with considerable morbimortality in women, especially in those with cardiovascular diseases.

Coronary microvascular dysfunction pathophysiology in COVID-19

Recently, accumulating evidence has highlighted the role of endothelial dysfunction in COVID-19 progression. Coronary microvascular dysfunction (CMD) plays a pivotal role in cardiovascular disease (CVD) and CVD-related risk factors (eg, age, gender, hypertension, diabetes mellitus, and obesity). Equally, these are also risk factors for COVID-19. The purpose of this review was to explore CMD pathophysiology in COVID-19, based on recent evidence. COVID-19 mechanisms were reviewed in terms of imbalanced renin-angiotensin-aldosterone-systems (RAAS), systemic inflammation and immune responses, endothelial dysfunction, and coagulatory disorders. Based on these mechanisms, we addressed CMD pathophysiology within the context of COVID-19, from five perspectives. The first was the disarrangement of local RAAS and Kallikrein-kinin-systems attributable to SARS-Cov-2 entry, and the concomitant decrease in coronary microvascular endothelial angiotensin I converting enzyme 2 (ACE2) levels. The second was related to coronary microvascular obstruction, induced by COVID-19-associated systemic hyper-inflammation and pro-thrombotic state. The third was focused on how pneumonia/acute respiratory distress syndrome (ARDS)-related systemic hypoxia elicited oxidative stress in coronary microvessels and cardiac sympathetic nerve activation. Fourthly, we discussed how autonomic nerve dysfunction mediated by COVID-19-associated mental, physical, or physiological factors could elicit changes in coronary blood flow, resulting in CMD in COVID-19 patients. Finally, we analyzed reciprocity between the coronary microvascular endothelium and perivascular cellular structures due to viremia, SARS-CoV-2 dissemination, and systemic inflammation. These mechanisms may function either consecutively or intermittently, finally culminating in CMD-mediated cardiovascular symptoms in COVID-19 patients. However, the underlying molecular pathogenesis remains to be clarified.

Excess deaths associated with covid-19 pandemic in 2020: age and sex disaggregated time series analysis in 29 high income countries

OBJECTIVE

To estimate the direct and indirect effects of the covid-19 pandemic on mortality in 2020 in 29 high income countries with reliable and complete age and sex disaggregated mortality data.

DESIGN

Time series study of high income countries.

SETTING

Austria, Belgium, Czech Republic, Denmark, England and Wales, Estonia, Finland, France, Germany, Greece, Hungary, Israel, Italy, Latvia, Lithuania, the Netherlands, New Zealand, Northern Ireland, Norway, Poland, Portugal, Scotland, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, and United States.

PARTICIPANTS

Mortality data from the Short-term Mortality Fluctuations data series of the Human Mortality Database for 2016-20, harmonised and disaggregated by age and sex.

INTERVENTIONS

Covid-19 pandemic and associated policy measures.

MAIN OUTCOME MEASURES

Weekly excess deaths (observed deaths versus expected deaths predicted by model) in 2020, by sex and age (0-14, 15-64, 65-74, 75-84, and ≥85 years), estimated using an over-dispersed Poisson regression model that accounts for temporal trends and seasonal variability in mortality.

RESULTS

An estimated 979 000 (95% confidence interval 954 000 to 1 001 000) excess deaths occurred in 2020 in the 29 high income countries analysed. All countries had excess deaths in 2020, except New Zealand, Norway, and Denmark. The five countries with the highest absolute number of excess deaths were the US (458 000, 454 000 to 461 000), Italy (89 100, 87 500 to 90 700), England and Wales (85 400, 83 900 to 86 800), Spain (84 100, 82 800 to 85 300), and Poland (60 100, 58 800 to 61 300). New Zealand had lower overall mortality than expected (-2500, -2900 to -2100). In many countries, the estimated number of excess deaths substantially exceeded the number of reported deaths from covid-19. The highest excess death rates (per 100 000) in men were in Lithuania (285, 259 to 311), Poland (191, 184 to 197), Spain (179, 174 to 184), Hungary (174, 161 to 188), and Italy (168, 163 to 173); the highest rates in women were in Lithuania (210, 185 to 234), Spain (180, 175 to 185), Hungary (169, 156 to 182), Slovenia (158, 132 to 184), and Belgium (151, 141 to 162). Little evidence was found of subsequent compensatory reductions following excess mortality.

CONCLUSION

Approximately one million excess deaths occurred in 2020 in these 29 high income countries. Age standardised excess death rates were higher in men than women in almost all countries. Excess deaths substantially exceeded reported deaths from covid-19 in many countries, indicating that determining the full impact of the pandemic on mortality requires assessment of excess deaths. Many countries had lower deaths than expected in children <15 years. Sex inequality in mortality widened further in most countries in 2020.

Immunological aspects and gender bias during respiratory viral infections including novel Coronavirus disease-19 (COVID-19): A scoping review

The human immune system is not adequately equipped to eliminate new microbes and could result in serious damage on first exposure. This is primarily attributed to the exaggerated immune response (inflammatory disease), which may prove detrimental to the host, as evidenced by SARS‐CoV‐2 infection. From the experiences of Novel Coronavirus Disease‐19 to date, male patients are likely to suffer from high‐intensity inflammation and disease severity than the female population. Hormones are considered the significant pillars of sex differences responsible for the discrepancy in immune response exhibited by males and females. Females appear to be better equipped to counter invading respiratory viral pathogens, including the novel SARS‐CoV‐2, than males. It can be hypothesized that females are more shielded from disease severity, probably owing to the diverse action/influence of estrogen and other sex hormones on both cellular (thymus‐derived T lymphocytes) and humoral immunity (antibodies).

Hormones are considered as significant pillars of sex differences and influence both the innate as well as adaptive immune responses.

Sex hormones and their potential role in the immune responses has not been completely understood.

Females are more shielded from disease severity probably owing to their unique hormonal constitution.

In females, the immunological cells have been noted to restrict the spread of infections as compared to males.

Males suffer from increased severity of respiratory infections and are less prone to autoimmune disorders as compared to the female counterparts.

Estrogen and other sex hormones play a key role both in restricting the inflammatory responses and in effective clearance of pathogens including the novel Coronairus.

Recent Update on the Molecular Mechanisms of Gonadal Steroids Action in Adipose Tissue

The gonadal steroids, including androgens, estrogens and progestogens, are involved in the control of body fat distribution in humans. Nevertheless, not only the size and localization of the fat depots depend on the sex steroids levels, but they can also highly affect the functioning of adipose tissue. Namely, the gonadocorticoids can directly influence insulin signaling, lipid metabolism, fatty acid uptake and adipokine production. They may also alter energy balance and glucose homeostasis in adipocytes in an indirect way, e.g., by changing the expression level of aquaglyceroporins. This work presents the recent advances in understanding the molecular mechanism of how the gonadal steroids influence the functioning of adipose tissue leading to a set of detrimental metabolic consequences. Special attention is given here to highlighting the sexual dimorphism of adipocyte functioning in terms of health and disease. Particularly, we discuss the molecular background of metabolic disturbances occurring in consequence of hormonal imbalance which is characteristic of some common endocrinopathies such as the polycystic ovary syndrome. From this perspective, we highlight the potential drug targets and the active substances which can be used in personalized sex-specific management of metabolic diseases, in accord with the patient's hormonal status.

Molecular and Biological Mechanisms Underlying Gender Differences in COVID-19 Severity and Mortality

Globally, over two million people have perished due to the recent pandemic caused by SARS-CoV-2. The available epidemiological global data for SARS-CoV-2 portrays a higher rate of severity and mortality in males. Analyzing gender differences in the host mechanisms involved in SARS-CoV-2 infection and progression may offer insight into the more detrimental disease prognosis and clinical outcome in males. Therefore, we outline sexual dimorphisms which exist in particular host factors and elaborate on how they may contribute to the pronounced severity in male COVID-19 patients. This includes disparities detected in comorbidities, the ACE2 receptor, renin-angiotensin system (RAS), signaling molecules involved in SARS-CoV-2 replication, proteases which prime viral S protein, the immune response, and behavioral considerations. Moreover, we discuss sexual disparities associated with other viruses and a possible gender-dependent response to SARS-CoV-2 vaccines. By specifically highlighting these immune-endocrine processes as well as behavioral factors that differentially exist between the genders, we aim to offer a better understanding in the variations of SARS-CoV-2 pathogenicity.

Sex-Based Differences in COVID-19 Outcomes

Background: Smaller studies suggest lower morbidity and mortality associated with coronavirus disease 2019 (COVID-19) in women. Our aim is to assess the impact of female sex on outcomes in a large cohort of patients hospitalized with COVID-19. Materials and Methods: This is a retrospective observational cohort study of 10,630 adult patients hospitalized with a confirmed COVID-19 polymerase chain reaction between March 1, 2020 and April 27, 2020, with follow-up conducted through June 4, 2020. Logistic regression was used to examine the relationship between sex and the primary outcomes, including length of stay, admission to intensive care unit (ICU), need for mechanical ventilation, pressor requirement, and all-cause mortality as well as major adverse events and in-hospital COVID-19 treatments. Results: In the multivariable analysis, women had 27% lower odds of in-hospital mortality (odds ratio [OR] = 0.73, 95% confidence interval [CI] 0.66-0.81; p < 0.001), 24% lower odds of ICU admission (OR = 0.76, 95% CI 0.69-0.84; p < 0.001), 26% lower odds of mechanical ventilation (OR = 0.74, 95% CI 0.66-0.82; p < 0.001), and 25% lower odds of vasopressor requirement (OR = 0.75, 95% CI 0.67-0.84; p < 0.001). Women had 34% less odds of having acute cardiac injury (OR = 0.66, 95% CI 0.59-0.74; p < 0.001; n = 7,289), 16% less odds of acute kidney injury (OR = 0.84, 95% CI 0.76-0.92; p < 0.001; n = 9,840), and 27% less odds of venous thromboembolism (OR = 0.73, 95% CI 0.56-0.96; p < 0.02; c-statistic 0.85, n = 9,407). Conclusions: Female sex is associated with lower odds of in-hospital outcomes, major adverse events, and all-cause mortality. There may be protective mechanisms inherent to female sex, which explain differences in COVID-19 outcomes.

The effect of estrogen in coronavirus disease 2019

The outcomes of coronavirus disease 2019 (COVID-19) vary between men and women. Some statistical reports have shown that men have a higher risk of developing COVID-19 and suffer from worse outcomes than females. Although there are many factors that can explain the high prevalence of COVID-19 in men, such as lifestyle habits and the different profile of comorbidities among sexes, the distinctions between male and female immune systems cannot be ignored. It has been sufficiently shown that sex differences have a critical influence on the shaping of immune response, which then leads to different pathogenesis in infectious diseases. Compared with males, females typically have a more effective innate and adaptive immune response to viral infections in COVID-19. What’s more, there is a growing body of evidence showing that estrogen exerts an effect on the regulation of immune response. This article examines the effect and mechanism of estrogen on COVID-19.

Relation of Cardiovascular Risk Factors to Mortality and Cardiovascular Events in Hospitalized Patients With Coronavirus Disease 2019 (from the Yale COVID-19 Cardiovascular Registry)

Individuals with established cardiovascular disease or a high burden of cardiovascular risk factors may be particularly vulnerable to develop complications from coronavirus disease 2019 (COVID-19). We conducted a prospective cohort study at a tertiary care center to identify risk factors for in-hospital mortality and major adverse cardiovascular events (MACE; a composite of myocardial infarction, stroke, new acute decompensated heart failure, venous thromboembolism, ventricular or atrial arrhythmia, pericardial effusion, or aborted cardiac arrest) among consecutively hospitalized adults with COVID-19, using multivariable binary logistic regression analysis. The study population comprised 586 COVID-19 positive patients. Median age was 67 (IQR: 55 to 80) years, 47.4% were female, and 36.7% had cardiovascular disease. Considering risk factors, 60.2% had hypertension, 39.8% diabetes, and 38.6% hyperlipidemia. Eighty-two individuals (14.0%) died in-hospital, and 135 (23.0%) experienced MACE. In a model adjusted for demographic characteristics, clinical presentation, and laboratory findings, age (odds ratio [OR], 1.28 per 5 years; 95% confidence interval [CI], 1.13 to 1.45), previous ventricular arrhythmia (OR, 18.97; 95% CI, 3.68 to 97.88), use of P2Y₁₂-inhibitors (OR, 7.91; 95% CI, 1.64 to 38.17), higher C-reactive protein (OR, 1.81: 95% CI, 1.18 to 2.78), lower albumin (OR, 0.64: 95% CI, 0.47 to 0.86), and higher troponin T (OR, 1.84; 95% CI, 1.39 to 2.46) were associated with mortality (p <0.05). After adjustment for demographics, presentation, and laboratory findings, predictors of MACE were higher respiratory rates, altered mental status, and laboratory abnormalities, including higher troponin T (p <0.05). In conclusion, poor prognostic markers among hospitalized patients with COVID-19 included older age, pre-existing cardiovascular disease, respiratory failure, altered mental status, and higher troponin T concentrations.

Gender susceptibility to COVID-19: a review of the putative role of sex hormones and X chromosome

BACKGROUND

The recent emergence of COVID-19 poses a global health emergency. One of the most frequently reported data is sex-related severity and mortality: according to the last available analysis on 239,709 patients in Italy, lethality is 17.7% in men and 10.8% in women, with 59% of total deaths being men. Interestingly, the infection rate is lower in males than in females, with 45.8% and 54.2% of positive cases, respectively, suggesting that gender-related factor may worsen disease evolution. A tentative hypothesis to explain these findings is the role of angiotensin-converting enzyme 2 (ACE2) and serine protease TMPRSS2 involved in viral infection.

PURPOSE

In this review, we summarize the available evidence pointing to gender-related differences in ACE2 and TMPRSS2 expression, from both genetic and endocrine points of view.

RESULTS

Altogether, available evidence points toward two not-mutually exclusive mechanisms in gender susceptibility to COVID-19 by sex hormonal regulation of ACE2 and TMPRSS2. On one hand, ACE2 expression could be increased in women, either by estrogens or constitutively by X chromosome inactivation escape or by reduced methylation, providing a larger reservoir of ACE2 to maintain the fundamental equilibrium of RAS regulatory axis. On the other, low levels of androgens in women may keep at low levels TMPRSS2 expression, representing a further protective factor for the development of COVID-19 infection, despite the increased expression of ACE2, which represents the Trojan horse for SARS-CoV-2 entry.

CONCLUSIONS

Both mechanisms consistently point to the role of sex hormones and sex chromosomes in the differential severity and lethality of COVID-19 in men and women.

Sex differences in the case-fatality rates for COVID-19-A comparison of the age-related differences and consistency over seven countries

BACKGROUND

Early in the COVID-19 pandemic, it was noted that males seemed to have higher case-fatality rates than females. We examined the magnitude and consistency of the sex differences in age-specific case-fatality rates (CFRs) in seven countries.

METHODS

Data on the cases and deaths from COVID-19, by sex and age group, were extracted from the national official agencies from Denmark, England, Israel, Italy, Spain, Canada and Mexico. Age-specific CFRs were computed for males and females separately. The ratio of the male to female CFRs were computed and meta-analytic methods were used to obtained pooled estimates of the male to female ratio of the CFRs over the seven countries, for all age-groups. Meta-regression and sensitivity analysis were conducted to evaluate the age and country contribution to differences.

RESULTS

The CFRs were consistently higher in males at all ages. The pooled M:F CFR ratios were 1.71, 1.88, 2.11, 2.11, 1.84, 1.78 and 1.49, for ages 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, 80+ respectively. In meta-regression, age group and country were associated with the heterogeneity in the CFR ratios.

CONCLUSIONS

The sex differences in the age-specific CFRs are intriguing. Sex differences in the incidence and mortality have been found in many infectious diseases. For COVID-19, factors such as sex differences in the prevalence of underlying diseases may play a part in the CFR differences. However, the consistently greater case-fatality rates in males at all ages suggests that sex-related factors impact on the natural history of the disease. This could provide important clues as to the mechanisms underlying the severity of COVID-19 in some patients.