Low testosterone levels predict clinical adverse outcomes in SARS-CoV-2 pneumonia patients

Aromatase, testosterone, TMPRSS2: determinants of COVID-19 severity

BACKGROUND

Male sex has been identified as a risk factor for worse COVID-19 outcomes. This sex difference has been mostly attributed to the complex role of sex hormones. Cell surface entry of SARS-CoV-2 is mediated by the transmembrane protease serine 2 (TMPRSS2) which is under transcriptional regulation by androgens. P450 aromatase enzyme converts androgens to estrogens. This study measured concentrations of aromatase enzyme, testosterone, estradiol, and TMPRSS-2 in plasma of hospitalized COVID-19 patients to elucidate the dynamics of sex-linked disparity in COVID-19 and correlate them with disease severity and mortality.

METHODS

In this prospective cohort study, a total of 265 patients (41% women), age 18 years and older, who had a positive COVID-19 PCR test and were hospitalized for COVID-19 at Memorial Hermann Hospital in Houston, (between May 2020 and May 2021) were enrolled in the study if met inclusion criteria. Plasma concentrations of Testosterone, aromatase, TMPRSS-2, and estradiol were measured by ELISA. COVID-19 patients were dichotomized based on disease severity into moderate-severe (n = 146) or critical (n = 119). Mann Whitney U and logistic regression were used to correlate the analytes with disease severity and mortality.

RESULTS

TMPRSS2 (2.5 ± 0.31 vs. 1.73 ± 0.21 ng/mL, p < 0.01) and testosterone (1.2 ± 0.1 vs. 0.44 ± 0.12 ng/mL, p < 0.01) were significantly higher in men as compared to women with COVID-19 after adjusting for age in a multivariate model. There was no sex difference seen in the level of estradiol and aromatase in COVID-19 patients. TMPRSS2 and aromatase were higher, while testosterone was lower in patients with increased COVID-19 severity. They were independently associated with COVID-19 severity, after adjusting for several baseline risk factors in a multivariate logistic regression model. In terms of mortality, TMPRRS2 and aromatase levels were significantly higher in non-survivors.

CONCLUSIONS

Our study demonstrates that testosterone, aromatase, and TMPRSS2 are markers of COVID-19 severity. Estradiol levels do not change with disease severity in COVID-19. In terms of mortality prediction, higher aromatase and TMPRSS-2 levels can be used to predict mortality from COVID-19 in hospitalized patients. COVID-19 has caused over a million deaths in the U.S., with men often getting sicker than women. Testosterone, a male hormone, helps control a protein called TMPRSS-2, which allows the COVID-19 virus to spread more easily in the body. A protein called aromatase converts the male hormone testosterone into the female hormone estrogen. It is thought that female hormone estrogen helps protect women from getting seriously ill from COVID-19. To understand the role of these hormones in COVID-19 and sex differences, we measured levels of testosterone, estrogen, aromatase (which turns testosterone into estrogen), and TMPRSS-2 in hospitalized COVID-19 patients. We also checked how this level might reflect the severity of the disease. We found that critically ill COVID-19 patients (the ones in ICU) had higher levels of TMPRSS-2 and aromatase, and lower testosterone levels. When we used these hormone levels to predict death in hospitalized COVID-19 patients, higher levels of TMPRSS-2 and aromatase were linked to a lower chance of survival.

Differential gene expression of immune response in COVID-19 and its relationship with progression of COVID-19

Human immune response evolved in virus clearance and gene expression levels of immune response may be associated with progression of Coronavirus disease 2019 (COVID-19). Our current study aims to investigate the relationship between differential gene expression of immune response and progression of COVID-19. A total of 50 participants of COVID-19 group were studied, compared with 39 participants of healthy control group. There were different gene expression profiles in pathways of activation of neutrophil, defense response and adaptive immune response for COVID-19 group before treatment compared to the healthy control group. Distinct gene expression profiles showed that pathways of chemotaxis, immune response and antibacterial humoral response involved in rehabilitation of severe COVID-19 group while pathways of immune system process, defense response to virus and negative regulation of viral genome replication involved in rehabilitation of moderate COVID-19 group. Both protein expression of ATP-binding cassette transporter A1 levels and protein expression of low affinity Fc-receptor FcγRIIIb levels were significantly and positively correlated with COVID-19-IgM levels and might be suitable as biomarkers for monitoring of COVID-19. This study showed that differential gene expression of immune response predicted onset and rehabilitation of COVID-19.

Testosterone and estradiol reduce inflammation of human macrophages induced by anti-SARS-CoV-2 IgG

COVID-19, the disease caused by SARS-CoV-2, particularly causes severe inflammatory disease in elderly, obese, and male patients. Since both aging and obesity are associated with decreased testosterone and estradiol expression, we hypothesized that decreased hormone levels contribute to excessive inflammation in the context of COVID-19. Previously, we and others have shown that hyperinflammation in severe COVID-19 patients is induced by the production of pathogenic anti-spike IgG antibodies that activate alveolar macrophages. Therefore, we developed an in vitro assay in which we stimulated human macrophages with viral stimuli, anti-spike IgG immune complexes, and different sex hormones. Treatment with levels of testosterone reflecting young adults led to a significant reduction in TNF and IFN-γ production by human macrophages. In addition, estradiol significantly attenuated the production of a very broad panel of cytokines, including TNF, IL-1β, IL-6, IL-10, and IFN-γ. Both testosterone and estradiol reduced the expression of Fc gamma receptors IIa and III, the two main receptors responsible for anti-spike IgG-induced inflammation. Combined, these findings indicate that sex hormones reduce the inflammatory response of human alveolar macrophages to specific COVID-19-associated stimuli, thereby providing a potential immunological mechanism for the development of severe COVID-19 in both older male and female patients.

Sex hormones and the total testosterone:estradiol ratio as predictors of severe acute respiratory syndrome coronavirus 2 infection in hospitalized men

BACKGROUND

The predictive ability of the early determination of sex steroids and the total testosterone:estradiol ratio for the risk of severe coronavirus disease 2019 or the potential existence of a biological gradient in this relationship has not been evaluated.

OBJECTIVES

To assess the relationship of sex steroid levels and the total testosterone:estradiol ratio with the risk of severe acute respiratory syndrome coronavirus 2 infection in men, defined as the need for intensive care unit admission or death, and the predictive ability of each biomarker.

MATERIALS AND METHODS

This was a prospective observational study. We included all consecutive adult men with severe acute respiratory syndrome coronavirus 2 infections in a single center admitted to a general hospital ward or to the intensive care unit. Sex steroids were evaluated at the centralized laboratory of our hospital.

RESULTS

We recruited 98 patients, 54 (55.1%) of whom developed severe coronavirus disease in 2019. Compared to patients with nonsevere coronavirus disease 2019, patients with severe coronavirus disease 2019 had significantly lower serum levels of total testosterone (111 ± 89 vs. 191 ± 143 ng/dL; p < 0.001), dehydroepiandrosterone (1.69 ± 1.26 vs. 2.96 ± 2.64 ng/mL; p < 0.001), and dehydroepiandrosterone sulfate (91.72 ± 76.20 vs. 134.28 ± 98.261 μg/dL; p = 0.009), significantly higher levels of estradiol (64.61 ± 59.35 vs. 33.78 ± 13.78 pg/mL; p = 0.001), and significantly lower total testosterone:estradiol ratio (0.28 ± 0.31 vs. 0.70 ± 0.75; p < 0.001). The lower the serum level of androgen and the lower the total testosterone:estradiol ratio values, the higher the likelihood of developing severe coronavirus disease 2019, with the linear trend in the adjusted analyses being statistically significant for all parameters except for androstenedione (p = 0.064). In the receiver operating characteristic analysis, better predictive performance was shown by the total testosterone:estradiol ratio, with an area under the curve of 0.77 (95% confidence interval 0.68-0.87; p < 0.001).

DISCUSSION AND CONCLUSION

Our results suggest that men with severe acute respiratory syndrome coronavirus 2 infection, decreased androgen levels and increased estradiol levels have a higher likelihood of developing an unfavorable outcome. The total testosterone:estradiol ratio showed the best predictive ability.

Quantitative Proteomics of COVID-19 Recovered Patients Identifies Long-Term Changes in Sperm Proteins Leading to Cellular Stress in Spermatozoa

Following an initial recovery, COVID-19 survivors struggle with a spectrum of persistent medical complications, including fatigue, breathlessness, weight loss, hair loss, and attention deficits. Additionally, there is growing evidence of adverse effects of COVID-19 on the male reproductive system. This investigation seeks to understand the long-term ramifications on male fertility by examining hormonal profiles, semen parameters, and sperm proteome of recovered COVID-19 patients compared to controls. The serum hormone profiles between the two groups showed minimal variations except for prolactin, cortisol, and testosterone levels. Testosterone levels were slightly lower, while prolactin and cortisol were elevated in COVID-19 cases compared to controls. Though semen parameters exhibited no significant disparities between the COVID-19 and control groups, quantitative proteomics analysis revealed changes in sperm proteins. It identified 190 differentially expressed proteins, of which 161 were upregulated and 29 downregulated in COVID-19 cases. Western blotting analysis validated the differential expression of serpin B4 and calpain 2. Bioinformatics analysis signifies cellular stress in the spermatozoa of COVID-19 recovered patients and thus, SOD and MDA levels in semen were measured. MDA levels were found to be significantly elevated, indicating lipid peroxidation in COVID-19 samples. While the effects of COVID-19 on semen parameters may exhibit a potential for reversal within a short duration, the alterations it inflicts on sperm proteome are persisting consequences on male fertility. This study paves the path for further research and emphasizes the significance of comprehending the complex molecular processes underlying the long-term consequences of COVID-19 on male reproductive health.

Investigating the effects of the Omicron variant of COVID-19 on sperm parameters and serum levels of male sexual hormones: Prospective observational study

Background

With the progress and prevalence of COVID-19, concerns have arisen regarding its impact on men's sexual health. Therefore, this study was conducted with the aim of examining the effects of COVID-19 on serum levels of sex hormones and semen.

Methods

Sixty participants who met the study inclusion criteria enrolled in this study between January and April 2022. The individuals were divided into three groups (n = 20): healthy, COVID-19 positive, and recovered from COVID-19. Blood and semen samples were collected from the participants. Serum levels of sex hormones and semen were evaluated both macroscopically and microscopically.

Results

Our study results showed that the most common symptoms observed in the COVID-19 group were cough (100 %), fever (100 %), fatigue (95 %), and runny nose (90 %). Serum levels of sex hormones (testosterone, FSH, and prolactin) in the COVID-19 group were significantly decreased compared to the healthy group. Microscopic examination of semen revealed significant differences in vitality, progressive, and motile parameters among the three groups, with a decrease observed in the COVID-19 group.

Conclusion

These results indicate that COVID-19 may have a negative impact on men's sexual health, potentially affecting hormone production and sperm quality. Further research is needed to determine the long-term effects of COVID-19 on male fertility and to explore potential treatment options.

Digit ratios and hospitalization for COVID-19: A test of the low-androgen-driven and high-androgen-driven theories of COVID-19 severity

BACKGROUND

Sex hormones are likely to be important determinants of COVID-19 severity, and two opposing explanations regarding severity, the low-androgen-driven and high-androgen-driven theories, seek to explain this pattern. Digit ratios are sex dependent (males < females) and are claimed to be markers for both prenatal and postnatal testosterone.

OBJECTIVES

Here, we use a measure of COVID-19severity (hospitalization), compare digit ratios in patients and controls and consider whether vaccination status changed these associations.

MATERIAL AND METHODS

Four digits were measured (2D, 3D, 4D, 5D). There were 194 participants (94 hospitalized patients [45 men] and 100 controls [53 men]) in Sample I and 162 participants (100 hospitalized [42 men], including 40 vaccinated and 62 controls [32 men]) in Sample II. Six ratios were calculated (2D:3D; 2D:4D; 2D:5D; 3D:4D; 3D:5D, 4D:5D) and compared between COVID-19 hospitalized and non-hospitalized patients and vaccinated and non-vaccinated.

RESULTS

In comparison to controls, we found higher ("feminized") means in patient ratios that included 5D (2D:5D; 3D:5D; 4D:5D) in both samples. The differences were independent of sex and age. Hospitalized patients with COVID-19 have higher (feminized) means and higher standard deviations (SDs) for 5D digit ratios.

DISCUSSION

Digit ratios are sex dependent (males < females) and are considered as markers for both prenatal and postnatal testosterone. If verified in future studies, the results will be helpful in regard to targeting mortality-reducing therapies for COVID-19 in certain groups of patients.

CONCLUSION

We conclude that the association between high (feminized) 5D ratios and hospitalization supports the low-androgen-driven theory of COVID-19 severity.

Impact of COVID-19 on testicular function: a systematic review and meta-analysis

INTRODUCTION

Studies investigating the effects of SARS-CoV-2 on male reproductive function are few and heterogeneous, and results are often conflicting. This systematic review and meta-analysis was carried out on studies conducted in men with active or anamnestic SARS-CoV-2 infection to evaluate its consequences on the male sex hormone profile and semen parameters.

MATERIALS AND METHOD

This meta-analysis follows the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocols. PubMed, Scopus, Cochrane, and Embase databases were searched to identify relevant studies. We originally selected 3553 articles. After the eligibility phase, 16 articles met our inclusion criteria encompassing 11 case-control studies and 5 cohort studies (2 prospective and 3 retrospective studies). We performed the quantitative analysis with Comprehensive Meta-Analysis Software. Cochran-Q and heterogeneity (I2) indexes were used to assess statistical heterogeneity. Sensitivity analysis and publication bias tests were also performed.

RESULTS

Overall, 1250 patients with active or recent (up to 80 days before) COVID-19 infection and 1232 matched healthy controls were included. Sperm concentration, total sperm count, and total motility were significantly lower in patients compared with controls. Patients also showed lower levels of total testosterone and follicle-stimulating hormone, and higher levels of luteinizing hormone, 17β-estradiol, and prolactin compared with healthy controls. None of the included studies found the presence of SARS-CoV-2 mRNA in the semen of infected patients.

CONCLUSION

The present systematic review and meta-analysis suggests the presence of an association between SARS-CoV-2 infection and primary testicular damage manifested with a picture of altered steroidogenesis and worsening spermatogenesis. The absence of the virus in the seminal fluid indicates a low possibility of sexual transmission of the infection to partners and offspring. However, our findings mostly show short-term follow-up, while few studies have considered the long-term consequences of the viral infection, thus further studies are needed to evaluate the long-term consequences on male reproductive health.

Is SARS-CoV-2-induced disease a decisive factor influencing testosterone in males? Findings from a case-control ex post facto study

BACKGROUND

Whether the observed lower total testosterone (tT) levels in male patients with COVID-19 are caused by a direct impact of SARS-CoV-2 infection or are collateral phenomena shared by other systemic inflammatory conditions has not yet been clarified.

OBJECTIVES

To investigate the independent role of COVID-19 in reducing circulating tT levels in men.

MATERIALS AND METHODS

We compared demographic, clinical, and hormonal values of patients with laboratory confirmed COVID-19 admitted during the first wave of the pandemic with a cohort of consecutive male patients admitted to the intensive care unit (ICU) of the same academic center because of severe acute respiratory distress syndrome (ARDS) but without SARS-CoV-2 infection and no previous history of COVID-19. Linear regression model tested the independent impact of COVID-19 on circulating tT levels. Logistic regression model was used to test predictors of death in the entire cohort.

RESULTS

Of 286 patients with COVID-19, 70 men had been admitted to the ICU ( = cases) and were compared to 79 patients equally admitted to ICU because of severe ARDS but negative for SARS-CoV-2 infection and without previous history of COVID-19 ( = controls). Controls were further grouped into noninfective (n = 49) and infective-ARDS (n = 30) patients. At baseline, controls were older (p = 0.01) and had more comorbidities (p < 0.0001). Overall, cases admitted to ICU had significantly lower circulating tT levels compared to controls (0.9 nmol/L vs. 2.1 nmol/L; vs. 1.2 nmol/L; p = 0.03). At linear regression, being negative for COVID-19 was associated with higher tT levels (Coeff: 2.13; 95% confidence interval - CI 0.71-3.56; p = 0.004) after adjusting for age, BMI, comorbidities and IL-6 levels. Only age and IL-6 levels emerged to be associated with higher risk of death regardless of COVID-19 status.

CONCLUSIONS

This case-control ex post facto study showed lower tT levels in men with COVID-19 compared to those without COVID-19 despite both groups have been equally admitted to ICU for severe ARDS, thus suggesting a possible direct impact of SARS-CoV-2 infection toward circulating tT levels and a consequent more severe clinical outcome.

Search traffic for inflatable penile prosthesis increased following the COVID-19 pandemic in the United States: a Google Trends analysis

We aimed to determine the impact of the COVID-19 pandemic on search trends for inflatable penile implants in the US. Search trends for inflatable penile implants ranging from 2016 through 2023 were analyzed utilizing Google Trends. Associations between search trends and US Census Bureau data, including average household income and per capita income, were analyzed. Pre- and post- COVID-19, the interest in inflatable penile implants has been steadily increasing on average in the US. The average household income for counties with the highest interest in inflatable penile implants during the pre-COVID era was $53,136, whereas for the counties with the highest interest in inflatable penile implants in the post-COVID era, the average decreased to $50,940. Similarly, the average per capita median decreased from $35,209 to $34,547. Search traffic for inflatable penile prosthesis increased following the pandemic in the US. Nevertheless, post-pandemic, individuals with lower income levels showed no change in interest in penile implant searches compared to the pre-pandemic period. Understanding this steadiness in interest can inform healthcare professionals and policymakers to tailor interventions and educational efforts to reach a broader audience, ensuring equitable access to information and healthcare resources.

Top-cited articles in andrology journals from 2013-2022: a bibliometric analysis

Bibliometric analyses serve to identify influential articles that have shaped medical practice and fostered new research ideas. Over the past decade, research in andrology has witnessed exponential growth, with an increasing number of academic publications, collaborations, and research innovations. However, there is a lack of literature that has identified the top-cited andrology articles. We conducted a bibliometric analysis to identify the top 1000 citations in andrology journals, with a focus on the top funding agencies, authors, institutions, countries/regions, and journals. To perform this analysis, we identified the top-cited articles in andrology journals as indexed in the Web of Science Core Collection. From 2013 through 2022, we found a total of 9827 articles published in andrology journals. The top publishers included "Andrology," the "Asian Journal of Andrology," and "Andrologia." The top affiliations contributing to research include the Cleveland Clinic Foundation (269 publications), Egyptian Knowledge Bank (EKB) (265), and Shanghai Jiao Tong University (202). Funding was primarily provided by notable agencies such as the National Natural Science Foundation of China (905 grants), United States Department of Health Human Services (321), and National Institutes of Health (NIH USA) (317). The present bibliometric analysis highlights andrology research from 2013 through 2022, offering key insights into leading contributors, influential authors, prominent funding sources, and major trends in the field.

COVID-19 and male fertility: short- and long-term impacts of asymptomatic vs. symptomatic infection on male reproductive potential

Background

Studies exploring the effect of COVID-19 on male reproductive system suggest a detrimental association, however with conflicting results. The aim of this study was to assess the association between COVID-19 infection and male reproductive potential including hormone profiles and semen parameters.

Methods

This prospective cohort study included 48 patients with confirmed COVID-19 infection. Patients were subdivided into an asymptomatic group (n = 30) and a group with COVID-19 symptoms (n = 18). Serum hormone levels including testosterone, LH, FSH and estradiol were collected during active infection (baseline, time 0), and at 3 and 6 months following COVID-19 infection. Semen samples (basic semen analysis and oxidation reduction potential) were examined at 3 and 6 months following infection. Student and paired-t tests were used to compare continuous variables between the study groups and across the studied time intervals, respectively. Multivariate binary logistic regression analysis was performed to explore predictors for COVID-19 symptoms during active infection.

Results

Patients with COVID-19 symptoms were significantly older (p = 0.02) and had significantly lower serum testosterone levels (p = 0.01) and significantly higher LH: testosterone ratio (p = 0.01) than asymptomatic patients. Multivariate analysis revealed older age (OR =  1.18, p = 0.03) and lower serum testosterone level (OR = 0.8, p = 0.03) as independent predictors of symptomatic COVID-19 infection. Significant increase in testosterone (p < 0.001 for both) and decrease in LH (p = 0.02, p = 0.007) and LH: testosterone (p = 0.02, p = 0.005) levels were observed at 3 and 6 months in patients with COVID-19 symptoms. Asymptomatic patients demonstrated significant increase in testosterone (p = 0.02) and decrease in LH: testosterone (p = 0.04) levels only at 3 months following COVID-19 infection. No significant differences were observed between the two study groups with regards to the semen analysis results obtained at 3 or 6 months following COVID-19 infection.

Conclusion

Significantly lower testosterone values are associated with worse disease severity among men with COVID-19 infection. This association appears to be temporary as a significant increase in testosterone levels are witnessed as early as 3 months following recovery. No significant detrimental effect for COVID-19 infection on testicular sperm production is found in this patient population.

Male reproductive function before and after the adjustment of the COVID-19 prevention policy: a multicenter study in China

At the end of 2022, the adjustment of the coronavirus disease 2019 (COVID-19) pandemic control policy in China resulted in a large-scale increase in public infection. To compare the fertility parameters of male patients before and after the adjustments of the COVID-19 pandemic control policy in China, we collected data on patients' medical histories and laboratory examinations on their first visits between June 2022 and March 2023 in five different hospitals. Data were divided into five groups according to the timeline of the policy adjustment. The data we collected from male patients included semen quality and serum reproductive hormone levels, and intergroup comparisons were made using the Mann-Whitney U and Chi-square tests. In total, 16 784 cases underwent regular semen analysis, 11 180 had sperm morphology assessments, and 7200 had reproductive hormone analyses. The data showed declining trends in semen volume, sperm motility, and the progressive sperm motility rate after the policy adjustment. Subgroup comparison revealed an initial decrease and gradual recovery in progressive motility rate. Sperm morphology analysis showed increased neck and tail abnormalities after the policy adjustment. No significant change in hormone levels was observed. Following the adjustment of the COVID-19 prevention policy in China, a decline in sperm motility and morphology was observed. This trend may gradually recover over 2 months. After the policy adjustment, reproductive hormone levels were relatively stable throughout, except for an increase in luteinizing hormone (LH). These changes in semen parameters suggest that the policy adjustment had a short- to medium-term impact on male reproductive function.

Pioglitazone reverses alcohol-induced alterations in alveolar macrophage mitochondrial phenotype

BACKGROUND

People with alcohol use disorder (AUD) have an increased risk of developing pneumonia and pulmonary diseases. Alveolar macrophages (AMs) are immune cells of the lower respiratory tract that are necessary for clearance of pathogens. However, alcohol causes AM oxidative stress, mitochondrial damage and dysfunction, and diminished phagocytic capacity, leading to lung injury and immune suppression.

METHODS

AMs were isolated by bronchoalveolar lavage from people with AUD and male and female C57BL/6J mice given chronic ethanol (20% w/v, 12 weeks) in drinking water. The peroxisome proliferator-activated receptor γ ligand, pioglitazone, was used to treat human AMs ex vivo (10 μM, 24 h) and mice in vivo by oral gavage (10 mg/kg/day). Levels of AM mitochondrial superoxide and hypoxia-inducible factor-1 alpha (HIF-1α) mRNA, a marker of oxidative stress, were measured by fluorescence microscopy and RT-qPCR, respectively. Mouse AM phagocytic ability was determined by internalized Staphylococcus aureus, and mitochondrial capacity, dependency, and flexibility for glucose, long-chain fatty acid, and glutamine oxidation were measured using an extracellular flux analyzer. In vitro studies used a murine AM cell line, MH-S (±0.08% ethanol, 72 h) to investigate mitochondrial fuel oxidation and ATP-linked respiration.

RESULTS

Pioglitazone treatment decreased mitochondrial superoxide in AMs from people with AUD and ethanol-fed mice and HIF-1α mRNA in ethanol-fed mouse lungs. Pioglitazone also reversed mouse AM glutamine oxidation and glucose or long-chain fatty acid flexibility to meet basal oxidation needs. In vitro, ethanol decreased the rate of AM mitochondrial and total ATP production, and pioglitazone improved changes in glucose and glutamine oxidation.

CONCLUSIONS

Pioglitazone reversed chronic alcohol-induced oxidative stress in human AM and mitochondrial substrate oxidation flexibility and superoxide levels in mouse AM. Decreased ethanol-induced AM HIF-1α mRNA with pioglitazone suggests that this pathway may be a focus for metabolic-targeted therapeutics to improve morbidity and mortality in people with AUD.

Effect of SARS-CoV-2 viral infection on male sexual hormones levels post COVID-19 exposure: A systematic review and meta-analysis

INTRODUCTION

The COVID-19 can affect human testicles, thus will interfere the production of important male sexual hormone such as testosterone. Our study provides scientific evidence through systematic reviews and meta-analyses that focus on the effects of SARS-CoV-2 virus infection on male sexual hormonal disorders in patients post-exposure to COVID-19.

METHODS

This meta-analysis was made in accordance with the PRISMA guidelines. The outcomes of this study were the level of total testosterone, free testosterone, LH and FSH. Chi-square and I2 tests were used to evaluate heterogeneity between studies. The standardized mean deviation (SMD) with 95% CI were used and analysis was performed using the Review Manager 5.4 software.

RESULTS

The four included studies reported a total of 256 patients with COVID-19 with time of follow-up time post COVID-19 varying from one month to 7 months. The mean age distribution in the study was 34-57 years old. Total testosterone level (SMD = -158.71; 95% CI= -205.30 - -112.12; p<0.00001) was significantly higher at follow-up post COVID-19, while LH (SMD = 0.40; 95% CI = 0.15-0.65; p=0.002) was lower. The free testosterone level and FSH level showed no significant difference between baseline and after following up post COVID-19.

CONCLUSIONS

At follow up, the total testosterone level in patients with SARS-CoV-2 infection appeared to be elevated while LH was lower compared to the baseline.

Systematic review and meta-analysis of serum total testosterone and luteinizing hormone variations across hospitalized Covid-19 patients

A growing body of evidence suggests the role of male hypogonadism as a possible harbinger for poor clinical outcomes across hospitalized Covid-19 patients. Accordingly, we sought to investigate the impact of dysregulated hypothalamic-pituitary-gonadal axis on the severity of the clinical manifestations for hospitalized Covid-19 patients matched with healthy controls through a systematic review and meta-analysis. Databases were searched from inception to March 2022. A standardized mean difference (SMD) meta-analysis focused on hospitalized Covid-19 patients and healthy controls was developed for studies who reported total testosterone (TT) and luteinizing hormone (LH) levels at hospital admission. Overall, n = 18 series with n = 1575 patients between 2020 and 2022 were reviewed. A significant decrease in SMD of TT levels in Covid-19 patients compared to paired controls was observed (- 3.25 nmol/L, 95%CI - 0.57 and - 5.93). This reduction was even more consistent when matching severe Covid-19 patients with controls (- 5.04 nmol/L, 95%CI - 1.26 and - 8.82) but similar for Covid-19 survivors and non-survivors (- 3.04 nmol/L, 95%CI - 2.04 and - 4.05). No significant variation was observed for serum LH levels across studies. Patient related comorbidities, year of the pandemic, and total lymphocyte count were associated with the observed estimates. TT levels may be a useful serum marker of poor outcomes among Covid-19 patients. These findings may support the development of ad-hoc clinical trials in the Covid-19 risk-group classification and subsequent disease monitoring. The interplay between TT and immune response should be evaluated in future researches.

Understanding Covid-19: Digit ratios and duration of oxygen therapy in hospitalized Covid-19 patients

BACKGROUND

Covid-19 severity shows a sex difference (males>females) and progressive hypoxia among the most seriously affected. Digit ratios are sexually dimorphic and may be negatively-related to prenatal (2nd-to-4th digits' ratio; 2D:4D) and pubertal (3rd-to-5th digits' ratio; 3D:5D) testosterone. Oxygen therapy is important in Covid-19 treatment and low 2D:4D is linked to efficient oxygen metabolism. We consider relationships between digit ratios and duration of oxygen treatment in hospitalized Covid-19 patients.

METHODS

Digit lengths were measured from photographs of the patient's hands. Age, Sex, BMI, vaccination status and number of days of O2 treatment, were recorded.

RESULTS

There were 100 (58 women) patients. Sex differences (males

CONCLUSION

We have found that high (feminized) 2D:4D of males and females is positively related to duration of oxygen therapy. This adds to the evidence for links between severity of Covid-19 and national and individual level variation in foetal androgen (as measured by 2D:4D). We discuss our finding in the light of the "low-androgen-driven COVID-19 pandemic theory".

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Key Words

• COVID-19
• Digit ratio
• Oxygen therapy

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MESH Headings

• Humans
• Male
• Female
• Androgens
• Fingers/anatomy & histology
• Digit Ratios
• COVID-19/therapy
• Pandemics
• COVID-19 Drug Treatment
• Sex Characteristics
• Oxygen/therapeutic use

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Affiliation(s)

Anna Kasielska-Trojan Plastic, Reconstructive and Aesthetic Surgery Clinic, Institute of Surgery, Medical University of Lodz, Lodz, Poland.
Maciej Jabłkowski Department of Infectious and Liver Diseases, Medical University of Lodz, Lodz, Poland
Jolanta Białkowska-Warzecha Department of Infectious and Liver Diseases, Medical University of Lodz, Lodz, Poland
Oliwia Kwaśniewska Medical University of Lodz, Lodz, Poland
Bogusław Antoszewski Plastic, Reconstructive and Aesthetic Surgery Clinic, Institute of Surgery, Medical University of Lodz, Lodz, Poland

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The impact of acute SARS-CoV-2 on testicular function including insulin-like factor 3 (INSL3) in men with mild COVID-19: A longitudinal study

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may affect the male reproductive system as it uses angiotensin-converting enzyme (ACE)2, which is expressed in testicular tissue, as an entry point into the cell. Few studies have evaluated the long-term effects of mild coronavirus disease 2019 (COVID-19) on testicular function, and insulin-like factor 3 (INSL3) levels have not previously been assessed during acute SARS-CoV-2 infection.

OBJECTIVES

The aim of the study was to assess the impact of acute SARS-CoV-2 infection on testicular function including INSL3 and the presence of SARS-CoV-2 RNA in semen in non-hospitalised men with mild COVID-19.

MATERIALS AND METHODS

This longitudinal study included 36 non-hospitalised SARS-CoV-2-positive men (median age 29 years). Inclusion was within seven days following a positive SARS-CoV-2 reverse-transcription polymerase chain reaction test. Reproductive hormone levels, semen parameters, and the presence of SARS-CoV-2 RNA in oropharyngeal and semen samples were assessed during acute SARS-CoV-2 infection (baseline) and at three- and six-month follow-up. Wilcoxon matched-pair signed-rank (two samples) test was used to assess time-related alterations in reproductive hormone levels and semen parameters.

RESULTS

Lower plasma testosterone (T) (total and calculated free (c-fT)) and higher luteinising hormone (LH) concentrations were observed during acute SARS-CoV-2 infection (baseline) compared to three- and six-month follow-up. Consequently, ratios of c-fT/LH were lower at baseline compared to three- and six-month follow-up (p < 0.001 and p = 0.003, respectively). Concomitantly, lower INSL3 concentrations were observed at baseline compared to three-month follow-up (p = 0.01). The total number of motile spermatozoa was also lower at baseline compared to six-month follow-up (p = 0.02). The alterations were detected irrespective of whether the men had experienced SARS-CoV-2-related fever episodes or not. No SARS-CoV-2 RNA was detected in semen at any time point.

DISCUSSION AND CONCLUSION

This study showed a reduction in testicular function, which was for the first time confirmed by INSL3, in men mildly affected by SARS-CoV-2 infection. The risk of transmission of SARS-CoV-2 RNA via semen seems to be low. Febrile episodes may impact testicular function, but a direct effect of SARS-CoV-2 cannot be excluded.

Effect of COVID-19 on sexual and reproductive functions of Egyptian males following recovery: A cross sectional study

INTRODUCTION

We aimed to assess the sexual and the reproductive functions in males post COVID-19 infection in Beni-Suef Governorate.

METHODS

One hundred men were recruited in the current study. All participants were assessed by the Arabic validated version of the International Index of the Erectile Function 5 (ArIIEF-5), semen analysis, and Hospital Depression and Anxiety Scale (HADS). Finally, morning testosterone serum level was measured.

RESULTS

There were significant decreases in the sperm total motility, the ArIIEF-5 score, and serum total testosterone in the post COVID-19 patients after 3 months when compared to the controls. However, there were significant increases in the sperm total motility, the ArIIEF-5 score, and serum total testosterone in the post COVID-19 patients after 6 months group when compared to the post COVID-19 patients after 3 months group. Moreover, there was a significant increase in the HADS score in the post COVID-19 patients after 3 months when compared to the controls. In contrast, there was a significant decrease in the HADS score in the post COVID-19 patients after 6 months when compared to the post COVID-19 patients after 3 months.

CONCLUSION

Our study had shown temporary impairment of sexual and reproductive functions in post COVID-19 convalescent males especially after 6 months from the onset of the infection.

Establishment of sex-specific predictive models for critical illness in Chinese people with the Omicron variant

Introduction

The Omicron variant has rapidly spread throughout the world compared to the Delta variant and poses a great threat to global healthcare systems due to its immune evasion and rapid spread. Sex has been identified as a factor significantly associated with COVID-19 mortality, but it remains unclear which clinical indicators could be identified as risk factors in each sex group and which sex-specific risk factors might shape the worse clinical outcome, especially for Omicrons. This study aimed to confirm the relationship between sex and the progression of the Omicron variant and to explore its sex-biased risk factors.

Methods

We conducted a retrospective study including 1,132 hospitalized patients with the COVID-19 Omicron variant from 5 December 2022 to 25 January 2023 at Shanghai General Hospital, and the medical history data and clinical index data of the inpatients for possible sex differences were compared and analyzed. Then, a sex-specific Lasso regression was performed to select the variables significantly associated with critical illness, including intensive care unit admission, invasive mechanical ventilation, or death. A logistic regression was used to construct a sex-specific predictive model distinctively for the critical illness outcome using selected covariates.

Results

Among the collected 115 clinical indicators, up to 72 showed significant sex differences, including the difference in merit and the proportion of people with abnormalities. More importantly, males had greater critical illness (28.4% vs. 19.9%) and a significantly higher intensive care unit occupancy (20.96% vs. 14.49%) and mortality (13.2% vs. 4.9%), and males over 80 showed worse outcomes than females. Predictive models (AUC: 0.861 for males and 0.898 for females) showed 12 risk factors for males and 10 for females. Through a comprehensive sex-stratified analysis of a large cohort of hospitalized Omicron-infected patients, we identified the specific risk factors for critical illness by developing prediction models.

Discussion

Sex disparities and the identified risk factors should be considered, especially in the personalized prevention and treatment of the COVID-19 Omicron variant.

Antiandrogens as Therapies for COVID-19: A Systematic Review

BACKGROUND

In 2019, the breakthrough of the coronavirus 2 disease (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represented one of the major issues of our recent history. Different drugs have been tested to rapidly find effective anti-viral treatments and, among these, antiandrogens have been suggested to play a role in mediating SARS-CoV-2 infection. Considering the high heterogeneity of studies on this topic, we decided to review the current literature.

METHODS

We performed a systematic review according to PRISMA guidelines. A search strategy was conducted on PUBMED and Medline. Only original articles published from March 2020 to 31 August 2023 investigating the possible protective role of antiandrogens were included. In vitro or preclinical studies and reports not in the English language were excluded. The main objective was to investigate how antiandrogens may interfere with COVID-19 outcomes.

RESULTS

Among 1755 records, we selected 31 studies, the majority of which consisted of retrospective clinical data collections and of randomized clinical trials during the first and second wave of the COVID-19 pandemic.

CONCLUSIONS

In conclusion, we can state that antiandrogens do not seem to protect individuals from SARS-CoV-2 infection and COVID-19 severity and, thus, their use should not be encouraged in this field.

Predicting Factors of Worse Prognosis in COVID-19: Results from a Cross-sectional Study on 52 Inpatients Admitted to the Internal Medicine Department

BACKGROUND

The initial phases of the COVID-19 pandemic posed a real need for clinicians to identify patients at risk of poor prognosis as soon as possible after hospital admission.

AIMS

The study aimed to assess the role of baseline anamnestic information, clinical parameters, instrumental examination, and serum biomarkers in predicting adverse outcomes of COVID-19 in a hospital setting of Internal Medicine.

METHODS

Fifty-two inpatients consecutively admitted to the Unit of Internal Medicine "Baccelli," Azienda Ospedaliero - Universitaria Policlinico of Bari (February 1 - May 31, 2021) due to confirmed COVID-19 were grouped into two categories based on the specific outcome: good prognosis (n=44), patients discharged at home after the acute phase of the infection; poor prognosis, a composite outcome of deaths and intensive care requirements (n=8). Data were extracted from medical records of patients who provided written informed consent to participate.

RESULTS

The two study groups had similar demographic, anthropometric, clinical, and radiological characteristics. Higher interleukin 6 (IL-6) levels and leucocyte count, and lower free triiodothyronine (fT3) levels were found in patients with poor than those with good prognosis. Higher IL-6 levels and leucocyte count, lower fT3 concentration, and pre-existing hypercholesterolemia were independent risk factors of poor outcomes in our study population. A predicting risk score, built by assigning one point if fT3 < 2 pg/mL, IL-6 >25 pg/mL, and leucocyte count >7,000 n/mm3, revealed that patients totalizing at least 2 points by applying the predicting score had a considerably higher risk of poor prognosis than those scoring <2 points (OR 24.35 (1.32; 448), p = 0.03). The weight of pre-existing hypercholesterolemia did not change the risk estimation.

CONCLUSION

Four specific baseline variables, one anamnestic (pre-existing hypercholesterolemia) and three laboratory parameters (leucocyte count, IL-6, and fT3), were significantly associated with poor prognosis as independent risk factors. To prevent adverse outcomes, the updated 4-point score could be useful in identifying at-risk patients, highlighting the need for specific trials to estimate the safety and efficacy of targeted treatments.

Male Hypogonadism After Recovery from Acute COVID-19 Infection: A Prospective Observational Study

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 can affect the hypothalamic-pituitary-gonadal axis (HPG) due to the expression of the angiotensin-converting enzyme 2 receptor.

OBJECTIVES

To assess the prevalence of hypogonadism and Sertoli cell dysfunction in coronavirus disease 2019 (COVID-19) male survivors.

METHOD

Male subjects recovered from acute COVID-19 infection were prospectively observed. The primary outcomes included the proportion of hypogonadism, defined biochemically as serum testosterone<230 ng/dL or CFT of<6.4 ng/mL if the total testosterone is between 230-320 ng/m. Sertoli cell dysfunction was defined as inhibin-B level<54.5 pg/mL. Subjects with hypogonadism were followed up at 12 months to assess the recovery of the HPG axis.

RESULTS

Eighty-three subjects aged≥18 years were evaluated at a median of 120 (±35) days post-recovery. Their mean age was 49.50±12.73 years, and the mean BMI was 26.84±5.62 kg/m2. Low testosterone was detected in 21 (24.71%) and low inhibin-B was detected in 14 (19.71%) out of 71 subjects at 3 months. Subjects with low testosterone were younger, with a mean age of 43.29±12.03 years (P-0.08) and higher BMI (P-0.012). The severity of COVID-19 infection, duration of hospitalization, and other factors were not significantly associated with low testosterone. At 12 months, 18 out of 21 subjects came for follow-up, of which 9 (50%) showed persistently low testosterone, suggestive of hypogonadism.

CONCLUSION

Following COVID-19 infection, testosterone levels recovered over time; however, a significant proportion of subjects had low levels at 12-month follow-up. These findings have long-term implications for the management of COVID-19 subjects.

Men, testosterone and Covid-19

Men have more severe Coronavirus disease 2019 (Covid-19) outcomes and higher mortality rates than women, and it was suggested that testosterone levels might promote severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and Covid-19 severity. However, clinical studies have not supported this theory. Studies have consistently shown that serum testosterone concentrations during acute Covid-19 in men are inversely proportional to the inflammatory cytokines and severity of illness. It is likely that lower testosterone concentrations in this setting are a result of acute Covid-19 illness on the hypothalamic-pituitary-testicular axis. Clinical trials that attempted to lower testosterone concentrations further or block androgen signaling acutely during Covid-19 in men did not result in improved Covid-19 outcomes. Additionally, pre-existing male hypogonadism, diagnosed before Covid-19 pandemic, was found to be a risk factor for hospitalization from Covid-19. In this review, we also discuss the preclinical and mechanistic studies that have evaluated the role of androgens in SARS-CoV-2 infection and illness. Finally, long-term consequences of Covid-19 on male reproductive health are reviewed. SARS-CoV-2 virus is known to infiltrate testis and induce orchitis in men, but it is unclear if Covid-19 leads to an increase in incidence of male hypogonadism.

Adult Male Hypogonadism: A Laboratory Medicine Perspective on Its Diagnosis and Management

Testosterone (T), the principal androgen secreted by the testes, plays an essential role in male health. Male hypogonadism is diagnosed based on a combination of associated clinical signs and symptoms and laboratory confirmation of low circulating T levels. In this review, we have highlighted factors, both biological and analytical, that introduce variation into the measurement of serum T concentrations in men; these need to be considered when requesting T levels and interpreting results. There is an ongoing need for analytical standardisation of T assays and harmonisation of pre- and post-analytical laboratory practices, particularly in relation to the laboratory reference intervals provided to clinicians. Further, there is a need to share with service users the most up-to-date and evidence-based action thresholds for serum T as recommended in the literature. Estimation of free testosterone may be helpful. Causes of secondary hypogonadism should be considered. A comprehensive approach is required in the management of male hypogonadism, including lifestyle modification as well as medication where appropriate. The goal of treatment is the resolution of symptoms as well as the optimisation of metabolic, cardiovascular, and bone health. The advice of an endocrinologist should be sought when there is doubt about the cause and appropriate management of the hypogonadism.

Neurological risks of COVID-19 in women: the complex immunology underpinning sex differences

The COVID-19 pandemic has uncovered many mysteries about SARS-CoV-2, including its potential to trigger abnormal autoimmune responses. Emerging evidence suggests women may face higher risks from COVID-induced autoimmunity manifesting as persistent neurological symptoms. Elucidating the mechanisms underlying this female susceptibility is now imperative. We synthesize key insights from existing studies on how COVID-19 infection can lead to immune tolerance loss, enabling autoreactive antibodies and lymphocyte production. These antibodies and lymphocytes infiltrate the central nervous system. Female sex hormones like estrogen and X-chromosome mediated effects likely contribute to dysregulated humoral immunity and cytokine profiles among women, increasing their predisposition. COVID-19 may also disrupt the delicate immunological balance of the female microbiome. These perturbations precipitate damage to neural damage through mechanisms like demyelination, neuroinflammation, and neurodegeneration - consistent with the observed neurological sequelae in women. An intentional focus on elucidating sex differences in COVID-19 pathogenesis is now needed to inform prognosis assessments and tailored interventions for female patients. From clinical monitoring to evaluating emerging immunomodulatory therapies, a nuanced women-centered approach considering the hormonal status and immunobiology will be vital to ensure equitable outcomes. Overall, deeper insights into the apparent female specificity of COVID-induced autoimmunity will accelerate the development of solutions mitigating associated neurological harm.

SARS-CoV-2 infection (COVID-19) and male fertility: Something we should be worried about?

As of 2021, roughly 5 million deaths were linked to SARS-CoV-2 infection based on World Health Organization estimates. The pandemic takes its staggering death toll, severely affecting the healthcare systems and leading to detrimental implications globally. While the severe impact on the respiratory system is well-established, the exact effect on male reproduction is still largely uncharted territory. When it comes to gender, men appear more vulnerable compared to women. Increasing evidence suggests that COVID-19 adversely affects spermatogenesis and hormonal balance in diverse ways. Semen parameters seem to be compromised at least temporarily, while long-term worsening needs to be clarified in studies with extended follow-up. For the time being, no data support the adverse effect of COVID-19 vaccines on a male's reproductive health. In the present article, we examine the available literature and briefly discuss the impact of the virus on reproduction and fertility. We further provide a comprehensive overview of the current status of vaccination and its potential effect on male fertility. Ultimately, we address the need for future well-designed large-scale trials before drawing definite conclusions on the exact impact of the virus on a male's fecundity.

Sex-Specific Total Testosterone and Dehydroepiandrosterone Sulfate Status in Noncritically Ill Hospitalized Patients with Coronavirus Disease 2019: A Cross-Sectional Study

BACKGROUND

In individuals with coronavirus disease 2019 (COVID-19), male subjects have consistently been linked to poor severity and prognosis. Data on sex hormones in non-critical COVID-19-infected patients are scarce. The aim of this study was to assess the status of total testosterone (TT) and dehydroepiandrosterone sulfate (DHEAS) among noncritical patients with COVID-19 according to sex and their associations with clinical and biochemical features.

MATERIALS AND METHODS

This cross-sectional observational study was done in the COVID-19 unit of a University hospital during the period of September 2021 to February 2022 among 91 adults (18-65 years) with reverse transcriptase- polymerase chain reaction confirmed noncritical COVID-19 patients. Blood was drawn by venipuncture before receiving steroids between 07:00 to 09:00 a.m. in a fasting state to measure serum TT and DHEAS by chemiluminescent microparticle immunoassay. Diagnosis and classification of COVID-19 were done according to World Health Organization's interim guidance. Age- and sex-specific laboratory reference values were used to classify the TT and DHEAS status of the patients.

RESULTS

Only three males (8.1%) had low TT and the rest had normal TT. On the other hand, 15 (27.8%) of the females had high TT with normal levels in the rest. Similarly, 11 (29.7%) males had low DHEAS. Females had low, normal, and high DHEAS in four (7.4%), 48 (88.9%), and two (3.7%) cases respectively. Males with moderate severity of COVID-19 had significantly lower DHEAS (post hoc P=0.038) than the mild group. Both TT (P=0.008) and DHEAS (P=0.023) significantly correlated with neutrophils/lymphocytes ratio and only DHEAS with platelets/lymphocytes ratio (P=0.044) in males. In females, TT significantly correlated with serum sodium (P=0.034).

CONCLUSION

In noncritical COVID-19 patients, substantial gender variations in TT and DHEAS were detected and correlated with severity markers in males.

Comparison of testosterone, FSH, LH and E2 hormone levels in infertility suspected males with COVID-19 infection

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an infectious disease that has many adverse impacts on many systems including reproduction. The direct effects of COVID-19 on urogenital system are still open to argue. This study aimed to compare testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) hormone levels in COVID-19 infected male individuals with infertility suspicion.

METHODS

One hundred five control (healthy) and 105 COVID-19 infected males aged between 20 to 54 years old were enrolled in the study. All patients were either diagnosed with primary or secondary infertility suspicion. The COVID-19 infection was diagnosed via reverse-transcription polymerase chain reaction test. Blood samples from patients were analyzed from the control and COVID-19 group to measure serum testosterone, FSH, LH, and E2 levels. Hormone levels were statistically compared between groups with the Independent T test.

RESULTS

In control and COVID-19 patients, no significance was determined for FSH and LH hormone values. Testosterone hormone were significantly decreased and E2 level was statistically increased in COVID-19 patients compared to that in the control group (P < .001).

CONCLUSION

COVID-19 is a viral disease that affects organ including gonads. COVID-19 infection decreased testosterone levels and increased E2 levels, which leading to disorders in male and female reproductivity.

From Diagnosis to Treatment: Comprehensive Care by Reproductive Urologists in Assisted Reproductive Technology

Infertility is a global health concern, with male factors playing an especially large role. Unfortunately, however, the contributions made by reproductive urologists in managing male infertility under assisted reproductive technology (ART) often go undervalued. This narrative review highlights the important role played by reproductive urologists in diagnosing and treating male infertility as well as any barriers they face when providing services. This manuscript presents a comprehensive review of reproductive urologists' role in managing male infertility, outlining their expertise in diagnosing and managing male infertility as well as reversible causes and performing surgical techniques such as sperm retrieval. This manuscript investigates the barriers limiting urologist involvement such as limited availability, awareness among healthcare professionals, and financial constraints. This study highlights a decrease in male fertility due to lifestyle factors like sedentary behavior, obesity, and substance abuse. It stresses the significance of conducting an evaluation process involving both male and female partners to identify any underlying factors contributing to infertility and to identify patients who do not require any interventions beyond ART. We conclude that engaging urologists more effectively in infertility management is key to optimizing fertility outcomes among couples undergoing assisted reproductive technology treatments and requires greater education among healthcare providers regarding the role urologists and lifestyle factors that could have an effect on male fertility.

Sex Differences and Cytokine Profiles among Patients Hospitalized for COVID-19 and during Their Recovery: The Predominance of Adhesion Molecules in Females and Oxidative Stress in Males

The severity and mortality of coronavirus disease 2019 (COVID-19) are greater in males than in females, though the infection rate is the same in the two sexes. We investigated sex hormone differences associated with the hyperinflammatory immune response to SARS-CoV-2 on the basis of patients' cytokine profiles and vaccination statuses. Clinical and laboratory data of 117 patients with COVID-19 were collected to examine sex differences associated with oxidative stress markers, neutrophil extracellular traps (NETs), and plasma cytokine levels up to 5 months from hospital admission. The testosterone and free testosterone levels were low in male patients with COVID-19 and returned to normal values after recovery from the disease. The dihydrotestosterone (DHT) levels were transiently reduced, while the sex hormone-binding globulin levels were decreased in post-COVID-19 male patients. The levels of the inflammatory cytokines interleukin-6 (IL-6) and IL-10 appeared generally increased at diagnosis and decreased in post-COVID-19 patients. In females, the concentration of tumor necrosis factor-alpha was increased by four times at diagnosis. The levels of the coagulation markers intercellular adhesion molecule-1 (ICAM-1) and E-selectin were consistently upregulated in post-COVID-19 female patients, in contrast to those of vascular cell adhesion molecule-1 (VCAM-1), P-selectin, and chemokine IL-8. DHT increased the levels of reactive oxygen species in the neutrophils of male patients, while estradiol decreased them in females. Markers for NET, such as circulating DNA and myeloperoxidase, were significantly more abundant in the patients' plasma. Sex hormones have a potential protective role during SARS-CoV-2 infection, which is weakened by impaired testosterone synthesis in men.

Impaired immune response against SARS-CoV-2 infection is the major factor indirectly altering reproductive function in COVID-19 patients: a narrative review

Coronavirus disease 2019 (COVID-19) is an infectious disease affecting multiple systems and organs, including the reproductive system. SARS-CoV-2, the virus that causes COVID-19, can damage reproductive organs through direct (angiotensin converting enzyme-2, ACE-2) and indirect mechanisms. The immune system plays an essential role in the homeostasis and function of the male and female reproductive systems. Therefore, an altered immune response related to infectious and inflammatory diseases can affect reproductive function and fertility in both males and females. This narrative review discussed the dysregulation of innate and adaptive systems induced by SARS-CoV-2 infection. We reviewed the evidence showing that this altered immune response in COVID-19 patients is the major indirect mechanism leading to adverse reproduction outcomes in these patients. We summarized studies reporting the long-term effect of SARS-CoV-2 infection on women's reproductive function and proposed the chronic inflammation and chronic autoimmunity characterizing long COVID as potential underlying mechanisms. Further studies are needed to clarify the role of autoimmunity and chronic inflammation (long COVID) in altered female reproduction function in COVID-19.

The unique interplay of mitochondrial oxidative phosphorylation (OXPHOS) and immunity and its potential implication for the sex- and age-related morbidity of severe COVID-19 patients

Aged male patients are more vulnerable to severe or critical symptoms of COVID-19, but the underlying mechanism remains elusive. In this study, we analyzed previously published scRNA-seq data from a large cohort of COVID-19 patients, castrated and regenerated mice, and bulk RNA-seq of a RNAi library of 400 genes, and revealed that both immunity and OXPHOS displayed cell-type-, sex-, and age-related variation in the severe or critical COVID-19 patients during disease progression, with a more prominent increase in immunity and decrease in OXPHOS in myeloid cells in the males relative to the females (60-69 years old). Male severe or critical patients above 70 years old were an exception in that the compromised negative correlation between OXPHOS and immunity in these patients was associated with its disordered transcriptional regulation. Finally, the expression levels of OXPHOS and androgens were revealed to be positively correlated, and the responses of macrophages to android fluctuation were more striking than other types of detected immune cells in the castrated mice model. Therefore, the interplay of OXPHOS and immunity displayed a cell-type-specific, age-related, and sex-biased pattern, and the underlying potential regulatory role of the hormonal milieu should not be neglected.

Association between COVID-19 and sexual health: an umbrella review

PURPOSE

We conducted this umbrella review to review the current evidence on the relationship between COVID-19 and sexual health in both men and women.

METHODS

We conducted searches in Pubmed, Embase, and the Cochrane dataset for meta-analyses that met our pre-set inclusion criteria. We included studies with detailed information investigating the link between COVID-19 and sexual health in men/women. We did not limit the language.

RESULTS

The results of the included studies frequently relied on the Female Sexual Function Index to assess sexual health in women. For men, the International Index of Male Function and hospital diagnoses were commonly used to assess sexual health. Currently, there is conflicting evidence regarding the impact of COVID-19 on sexual health. However, since most studies were observational in nature, additional study designs are necessary to draw definitive conclusions across different contexts.

CONCLUSION

Our findings highlight the importance of sexual health among COVID-19 patients and people affected due to COVID-19. Further critical studies should investigate the mechanism underlying the association between COVID-19 and sexual health.

SARS-CoV-2 and male infertility: from short- to long-term impacts

PURPOSE

The coronavirus 2019 (COVID-19) pandemic-caused by a new type of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-has posed severe impacts on public health worldwide and has resulted in a total of > 6 million deaths. Notably, male patients developed more complications and had mortality rates ~ 77% higher than those of female patients. The extensive expression of the SARS-CoV-2 receptor and related proteins in the male reproductive tract and the association of serum testosterone levels with viral entry and infection have brought attention to COVID-19's effects on male fertility.

METHODS

The peer-reviewed articles and reviews were obtained by searching for the keywords SARS-CoV-2, COVID-19, endocrine, spermatogenesis, epididymis, prostate, and vaccine in the databases of PubMed, Web of Science and Google Scholar from 2020-2022.

RESULTS

This review summarizes the effects of COVID-19 on the male reproductive system and investigates the impact of various types of SARS-CoV-2 vaccines on male reproductive health. We also present the underlying mechanisms by which SARS-CoV-2 affects male reproduction and discuss the potentially harmful effects of asymptomatic infections, as well as the long-term impact of COVID-19 on male reproductive health.

CONCLUSION

COVID-19 disrupted the HPG axis, which had negative impacts on spermatogenesis and the epididymis, albeit further investigations need to be performed. The development of vaccines against various SARS-CoV-2 variations is important to lower infection rates and long-term COVID risks.

COVID-19 associated thyroid dysfunction and other comorbidities and its management using phytochemical-based therapeutics: a natural way

The present severe acute respiratory syndrome-2 (SARS-CoV-2) mediated Coronavirus pandemic (COVID-19) and post-COVID-19 complications affect human life drastically. Patients who have been cured of COVID-19 infection are now experiencing post-COVID-19 associated comorbidities, which have increased mortality rates. The SARS-CoV-2 infection distresses the lungs, kidneys, gastrointestinal tract, and various endocrine glands, including the thyroid. The emergence of variants which includes Omicron (B.1.1.529) and its lineages threaten the world severely. Among different therapeutic approaches, phytochemical-based therapeutics are not only cost-effective but also have lesser side effects. Recently a plethora of studies have shown the therapeutic efficacy of various phytochemicals for the treatment of COVID-19. Besides this, various phytochemicals have been found efficacious in treating several inflammatory diseases, including thyroid-related anomalies. The method of the phytochemical formulation is quick and facile and the raw materials for such herbal preparations are approved worldwide for human use against certain disease conditions. Owing to the advantages of phytochemicals, this review primarily discusses the COVID-19-related thyroid dysfunction and the role of key phytochemicals to deal with thyroid anomaly and post-COVID-19 complications. Further, this review shed light on the mechanism via which COVID-19 and its related complication affect organ function of the body, along with the mechanistic insight into the way by which phytochemicals could help to cure post-COVID-19 complications in thyroid patients. Considering the advantages offered by phytochemicals as a safer and cost-effective medication they can be potentially used to combat COVID-19-associated comorbidities.

COVID-19 and Male Infertility: Is There a Role for Antioxidants?

Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), jeopardizes male fertility because of the vulnerability of the male reproductive system, especially the testes. This study evaluates the effects of the virus on testicular function and examines the potential role of antioxidants in mitigating the damage caused by oxidative stress (OS). A comprehensive PubMed search examined exocrine and endocrine testicular function alteration, the interplay between OS and COVID-19-induced defects, and the potential benefit of antioxidants. Although the virus is rarely directly detectable in sperm and testicular tissue, semen quality and hormonal balance are affected in patients, with some changes persisting throughout a spermatogenesis cycle. Testicular pathology in deceased patients shows defects in spermatogenesis, vascular changes, and inflammation. Acute primary hypogonadism is observed mainly in severely infected cases. Elevated OS and sperm DNA fragmentation markers suggest redox imbalance as a possible mechanism behind the fertility changes. COVID-19 vaccines appear to be safe for male fertility, but the efficacy of antioxidants to improve sperm quality after infection remains unproven due to limited research. Given the limited and inconclusive evidence, careful evaluation of men recovering from COVID-19 seeking fertility improvement is strongly recommended.

Hormone replacement therapy and COVID-19 outcomes in solid organ transplant recipients compared with the general population

Exogenous estrogen is associated with reduced coronavirus disease (COVID) mortality in nonimmunosuppressed/immunocompromised (non-ISC) postmenopausal females. Here, we examined the association of estrogen or testosterone hormone replacement therapy (HRT) with COVID outcomes in solid organ transplant recipients (SOTRs) compared to non-ISC individuals, given known differences in sex-based risk in these populations. SOTRs ≥45 years old with COVID-19 between April 1, 2020 and July 31, 2022 were identified using the National COVID Cohort Collaborative. The association of HRT use in the last 24 months (exogenous systemic estrogens for females; testosterone for males) with major adverse renal or cardiac events in the 90 days post-COVID diagnosis and other secondary outcomes were examined using multivariable Cox proportional hazards models and logistic regression. We repeated these analyses in a non-ISC control group for comparison. Our study included 1135 SOTRs and 43 383 immunocompetent patients on HRT with COVID-19. In non-ISC, HRT use was associated with lower risk of major adverse renal or cardiac events (adjusted hazard ratio [aHR], 0.61; 95% confidence interval [CI], 0.57-0.65 for females; aHR, 0.70; 95% CI, 0.65-0.77 for males) and all secondary outcomes. In SOTR, HRT reduced the risk of acute kidney injury (aHR, 0.79; 95% CI, 0.63-0.98) and mortality (aHR, 0.49; 95% CI, 0.28-0.85) in males with COVID but not in females. The potentially modifying effects of immunosuppression on the benefits of HRT requires further investigation.

Identifying hub genes and common biological pathways between COVID-19 and benign prostatic hyperplasia by machine learning algorithms

Background

COVID-19, a serious respiratory disease that has the potential to affect numerous organs, is a serious threat to the health of people around the world. The objective of this article is to investigate the potential biological targets and mechanisms by which SARS-CoV-2 affects benign prostatic hyperplasia (BPH) and related symptoms.

Methods

We downloaded the COVID-19 datasets (GSE157103 and GSE166253) and the BPH datasets (GSE7307 and GSE132714) from the Gene Expression Omnibus (GEO) database. In GSE157103 and GSE7307, differentially expressed genes (DEGs) were found using the "Limma" package, and the intersection was utilized to obtain common DEGs. Further analyses followed, including those using Protein-Protein Interaction (PPI), Gene Ontology (GO) function enrichment analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Potential hub genes were screened using three machine learning methods, and they were later verified using GSE132714 and GSE166253. The CIBERSORT analysis and the identification of transcription factors, miRNAs, and drugs as candidates were among the subsequent analyses.

Results

We identified 97 common DEGs from GSE157103 and GSE7307. According to the GO and KEGG analyses, the primary gene enrichment pathways were immune-related pathways. Machine learning methods were used to identify five hub genes (BIRC5, DNAJC4, DTL, LILRB2, and NDC80). They had good diagnostic properties in the training sets and were validated in the validation sets. According to CIBERSORT analysis, hub genes were closely related to CD4 memory activated of T cells, T cells regulatory and NK cells activated. The top 10 drug candidates (lucanthone, phytoestrogens, etoposide, dasatinib, piroxicam, pyrvinium, rapamycin, niclosamide, genistein, and testosterone) will also be evaluated by the P value, which is expected to be helpful for the treatment of COVID-19-infected patients with BPH.

Conclusion

Our findings reveal common signaling pathways, possible biological targets, and promising small molecule drugs for BPH and COVID-19. This is crucial to understand the potential common pathogenic and susceptibility pathways between them.

A negative association between triglyceride glucose-body mass index and testosterone in adult males: a cross-sectional study

Background and objectives

Insulin resistance (IR) is closely related to the decline or deficiency of testosterone in males. Triglyceride glucose-body mass (TyG-BMI) is considered to be a novel indicator of IR. We conducted this analysis to investigate the association between TyG-BMI and male testosterone, and to explore whether its ability to predict testosterone deficiency is superior to HOMA-IR and TyG.

Methods

This was a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES, 2011-2016). The TyG-BMI index was calculated from serum triglyceride, fasting plasma glucose and BMI. The association of TyG-BMI with male testosterone was estimated by weighted multivariable regression.

Results

We included 3394 participants for the final analysis. After adjusting for confounders, TyG-BMI was found to show an independent negative association with testosterone (β=-1.12, 95%CI: -1.50, -0.75, P<0.0001). Multivariate-adjusted beta also showed testosterone levels were significantly lower in the two highest TyG-BMI group (Q3, Q4) compared to the lowest group (Q1). Similar results were seen in all of the subgroup populations by stratified analysis (all P-interaction >0.05). Furthermore, ROC curve analysis indicated that the area under the curve of TyG-BMI index (0.73, 95% CI: 0.71, 0.75) was larger than that of HOMA-IR index (0.71, 95% CI: 0.69, 0.73) and TyG index (0.66, 95% CI: 0.64, 0.68).

Conclusion

Our result suggested a negative association between TyG-BMI index and testosterone in adult males. The predictability of the TyG-BMI index for testosterone deficiency is better than that of HOMA-IR index and TyG index.

Machine learning and integrative analysis identify the common pathogenesis of azoospermia complicated with COVID-19

Background

Although more recent evidence has indicated COVID-19 is prone to azoospermia, the common molecular mechanism of its occurrence remains to be elucidated. The aim of the present study is to further investigate the mechanism of this complication.

Methods

To discover the common differentially expressed genes (DEGs) and pathways of azoospermia and COVID-19, integrated weighted co-expression network (WGCNA), multiple machine learning analyses, and single-cell RNA-sequencing (scRNA-seq) were performed.

Results

Therefore, we screened two key network modules in the obstructive azoospermia (OA) and non-obstructive azoospermia (NOA) samples. The differentially expressed genes were mainly related to the immune system and infectious virus diseases. We then used multiple machine learning methods to detect biomarkers that differentiated OA from NOA. Enrichment analysis showed that azoospermia patients and COVID-19 patients shared a common IL-17 signaling pathway. In addition, GLO1, GPR135, DYNLL2, and EPB41L3 were identified as significant hub genes in these two diseases. Screening of two different molecular subtypes revealed that azoospermia-related genes were associated with clinicopathological characteristics of age, hospital-free-days, ventilator-free-days, charlson score, and d-dimer of patients with COVID-19 (P < 0.05). Finally, we used the Xsum method to predict potential drugs and single-cell sequencing data to further characterize whether azoospermia-related genes could validate the biological patterns of impaired spermatogenesis in cryptozoospermia patients.

Conclusion

Our study performs a comprehensive and integrated bioinformatics analysis of azoospermia and COVID-19. These hub genes and common pathways may provide new insights for further mechanism research.

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.

Serum testosterone mirrors inflammation parameters in females hospitalized with COVID-19

BACKGROUND

While low testosterone (T) was described as a predictor of unfavorable coronavirus-disease 19 (COVID-19) outcome in men, data concerning the role of T in women with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are scant and limited to small cohorts. This study investigated the relationship between serum T values and outcomes of COVID-19 in a large female hospitalized cohort.

METHODS

One-hundred-sixty-eight adult women (median age 77, range 18-100 years; 154 in post-menopause) hospitalized for COVID-19 were assessed for PaO2/Fio2 ratio, serum T and inflammatory parameters.

RESULTS

Median duration for hospital stay was 14.2 days (range 1-115) with overall mortality of 26% (n = 44). Subjects who died were significantly older (p < 0.001), had significantly more comorbidities (p = 0.015) and higher serum T (p = 0.040), white blood cells (p = 0.007), c-reactive protein (CRP; p < 0.001), interleukin-6 (IL-6; p < 0.001), procalcitonin (PCT; p < 0.001), lactate dehydrogenase (LDH; p = 0.001), D-dimer (p = 0.035), fibrinogen (p = 0.038) and lower serum free-triiodothyronine (FT3; p < 0.001) and luteinizing hormone (LH; p = 0.024) values. In post-menopausal women, significant associations were observed between T levels and serum CRP (rho: 0.23; p = 0.002), IL-6 (rho: 0.41; p < 0.001), LDH (rho: 0.34; p < 0.001), D-Dimer (rho: 0.21; p = 0.008), PCT (rho: 0.26; p = 0.001) and HDL cholesterol (rho:  - 0,22, p = 0.008). In multivariate regression analyses, serum T maintained the significant association with mortality after correction for age, coexistent comorbidities and serum LH and FT3, whereas it was lost after correction for inflammatory parameters.

CONCLUSION

In females, high serum T levels might be a mirror of inflammatory phenotype and worse COVID-19 course.

In vitro evidence against productive SARS-CoV-2 infection of human testicular cells: Bystander effects of infection mediate testicular injury

The hallmark of severe COVID-19 involves systemic cytokine storm and multi-organ injury including testicular inflammation, reduced testosterone, and germ cell depletion. The ACE2 receptor is also expressed in the resident testicular cells, however, SARS-CoV-2 infection and mechanisms of testicular injury are not fully understood. The testicular injury could be initiated by direct virus infection or exposure to systemic inflammatory mediators or viral antigens. We characterized SARS-CoV-2 infection in different human testicular 2D and 3D culture systems including primary Sertoli cells, Leydig cells, mixed seminiferous tubule cells (STC), and 3D human testicular organoids (HTO). Data shows that SARS-CoV-2 does not productively infect any testicular cell type. However, exposure of STC and HTO to inflammatory supernatant from infected airway epithelial cells and COVID-19 plasma decreased cell viability and resulted in the death of undifferentiated spermatogonia. Further, exposure to only SARS-CoV-2 Envelope protein caused inflammatory response and cytopathic effects dependent on TLR2, while Spike 1 or Nucleocapsid proteins did not. A similar trend was observed in the K18-hACE2 transgenic mice which demonstrated a disrupted tissue architecture with no evidence of virus replication in the testis that correlated with peak lung inflammation. Virus antigens including Spike 1 and Envelope proteins were also detected in the serum during the acute stage of the disease. Collectively, these data strongly suggest that testicular injury associated with SARS-CoV-2 infection is likely an indirect effect of exposure to systemic inflammation and/or SARS-CoV-2 antigens. Data also provide novel insights into the mechanism of testicular injury and could explain the clinical manifestation of testicular symptoms associated with severe COVID-19.

Association between COVID-19 and Male Fertility: Systematic Review and Meta-Analysis of Observational Studies

PURPOSE

Whether COVID-19 reduces male fertility remains requires further investigation. This meta-analysis and systematic review evaluated the impact of COVID-19 on male fertility.

MATERIALS AND METHODS

The literature in PubMed, Embase, MEDLINE, Web of Science, and Cochrane Library up to January 01, 2022 was systematically searched, and a meta-analysis was conducted to investigate the effect of COVID-19 on male fertility. Totally 17 studies with a total of 1,627 patients and 1,535 control subjects were included in our meta-analysis.

RESULTS

Regarding sperm quality, COVID-19 decreased the total sperm count (p=0.012), sperm concentration (p=0.001), total motility (p=0.001), progressive sperm motility (p=0.048), and viability (p=0.031). Subgroup analyses showed that different control group populations did not change the results. It was found that during the illness stage of COVID-19, semen volume decreased, and during the recovery stage of COVID-19, sperm concentration and total motility decreased <90 days. We found that sperm concentration and total motility decreased during recovery for ≥90 days. Fever because of COVID-19 significantly reduced sperm concentration and progressive sperm motility, and COVID-19 without fever ≥90 days, the sperm total motility and progressive sperm motility decreased. Regarding disease severity, the moderate type of COVID-19 significantly reduced sperm total motility, but not the mild type. Regarding sex hormones, COVID-19 increased prolactin and estradiol. Subgroup analyses showed that during the illness stage, COVID-19 decreased testosterone (T) levels and increased luteinizing hormone levels. A potential publication bias may have existed in our meta-analysis.

CONCLUSIONS

COVID-19 in men significantly reduced sperm quality and caused sex hormone disruption. COVID-19 had long-term effects on sperm quality, especially on sperm concentration and total motility. It is critical to conduct larger multicenter studies to determine the consequences of COVID-19 on male fertility.

Estradiol and Dihydrotestosterone Levels in COVID-19 Patients

OBJECTIVE

To determine differences in plasma sex hormone levels in male and female coronavirus disease 2019 (COVID-19) patients and healthy volunteers (HVs) because cell entry of severe acute respiratory syndrome coronavirus 2 occurs via the angiotensin-converting enzyme 2 receptor which is downregulated by 17β-estradiol.

PATIENTS AND METHODS

Citrated plasma samples were collected from 101 patients with COVID-19 upon presentation to the emergency department and from 40 HVs between November 1, 2020, and May 30, 2021. Plasma 17β-estradiol and 5α-dihydrotestosterone (DHT) levels were measured using enzyme-linked immunosorbent assay (pg/mL). Data are presented as median and quartiles (IQR). Wilcoxon rank sum test with a P value less than .05 was considered significant.

RESULTS

Patients with COVID-19 (median age, 49 years) included 51 males and 50 females (25 postmenopausal). Hospital admission was required for 58.8% of male patients (n = 30) and 48.0% of female patients (n = 24) (66.7% postmenopausal, n = 16) Healthy volunteers (median age, 41 years) included 20 males and 20 females (9 postmenopausal). Female patients with COVID-19 were found to have decreased 17β-estradiol levels (18.5 [IQR, 10.5-32.3] pg/mL; 41.4 [IQR, 15.5-111.0] pg/mL, P=.025), and lower 17β-estradiol to DHT ratios (0.073 [IQR, 0.052-0.159] pg/mL; 0.207 [IQR, 0.104-0.538] pg/mL, P=.015) than female HVs. Male patients with COVID-19 were found to have decreased DHT levels (302.8 [IQR, 249.9-470.8] pg/mL; 457.2 [IQR, 368.7-844.3] pg/mL, P=.005), compared with male HVs. Levels of DHT did not differ between female patients with COVID-19 and female HVs, whereas 17β-estradiol levels did not differ between male patients with COVID-19 and male HVs.

CONCLUSION

Sex hormone levels differ between patients with COVID-19 and HVs, with sex-specific patterns of hypogonadism in males and females. These alterations may be associated with disease development and severity.

Sex hormones in SARS-CoV-2 susceptibility: key players or confounders?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a clear sex disparity in clinical outcomes. Hence, the interaction between sex hormones, virus entry receptors and immune responses has attracted major interest as a target for the prevention and treatment of SARS-CoV-2 infections. This Review summarizes the current understanding of the roles of androgens, oestrogens and progesterone in the regulation of virus entry receptors and disease progression of coronavirus disease 2019 (COVID-19) as well as their therapeutic value. Although many experimental and clinical studies have analysed potential mechanisms by which female sex hormones might provide protection against SARS-CoV-2 infectivity, there is currently no clear evidence for a sex-specific expression of virus entry receptors. In addition, reports describing an influence of oestrogen, progesterone and androgens on the course of COVID-19 vary widely. Current data also do not support the administration of oestradiol in COVID-19. The conflicting evidence and lack of consensus results from a paucity of mechanistic studies and clinical trials reporting sex-disaggregated data. Further, the influence of variables beyond biological factors (sex), such as sociocultural factors (gender), on COVID-19 manifestations has not been investigated. Future research will have to fill this knowledge gap as the influence of sex and gender on COVID-19 will be essential to understanding and managing the long-term consequences of this pandemic.

Gender-Specific Impact of Sex Hormones on the Immune System

Sex hormones are key determinants of gender-related differences and regulate growth and development during puberty. They also exert a broad range modulation of immune cell functions, and a dichotomy exists in the immune response between the sexes. Both clinical and animal models have demonstrated that androgens, estrogens, and progestogens mediate many of the gender-specific differences in immune responses, from the susceptibility to infectious diseases to the prevalence of autoimmune disorders. Androgens and progestogens mainly promote immunosuppressive or immunomodulatory effects, whereas estrogens enhance humoral immunity both in men and in women. This study summarizes the available evidence regarding the physiological effects of sex hormones on human immune cell function and the underlying biological mechanisms, focusing on gender differences triggered by different amounts of androgens between males and females.

Autopsy Study of Testicles in COVID-19: Upregulation of Immune-Related Genes and Downregulation of Testis-Specific Genes

CONTEXT

Infection by SARS-CoV-2 may be associated with testicular dysfunction that could affect male fertility.

OBJECTIVE

Testicles of fatal COVID-19 cases were investigated to detect virus in tissue and to evaluate histopathological and transcriptomic changes.

METHODS

Three groups were compared: (a) uninfected controls (subjects dying of trauma or sudden cardiac death; n = 10); (b) subjects dying of COVID-19 (virus-negative in testes; n = 15); (c) subjects dying of COVID-19 (virus-positive in testes; n = 9). SARS-CoV-2 genome and nucleocapsid antigen were probed using RT-PCR, in situ hybridization, and immunohistochemistry (IHC). Infiltrating leukocytes were typed by IHC. mRNA transcripts of immune-related and testis-specific genes were quantified using the nCounter method.

RESULTS

SARS-CoV-2 was detected in testis tissue of 9/24 (37%) COVID-19 cases accompanied by scattered T-cell and macrophage infiltrates. Size of testicles and counts of spermatogenic cells were not significantly different among groups. Analysis of mRNA transcripts showed that in virus-positive testes immune processes were activated (interferon-alpha and -gamma pathways). By contrast, transcription of 12 testis-specific genes was downregulated, independently of virus positivity in tissue. By IHC, expression of the luteinizing hormone/choriogonadotropin receptor was enhanced in virus-positive compared to virus-negative testicles, while expression of receptors for androgens and the follicle-stimulating hormone were not significantly different among groups.

CONCLUSION

In lethal COVID-19 cases, infection of testicular cells is not uncommon. Viral infection associates with activation of interferon pathways and downregulation of testis-specific genes involved in spermatogenesis. Due to the exceedingly high numbers of infected people in the pandemic, the impact of virus on fertility should be further investigated.

SARS-CoV-2, fertility and assisted reproduction

BACKGROUND

In 2020, SARS-CoV-2 and the COVID-19 pandemic had a huge impact on the access to and provision of ART treatments. Gradually, knowledge of the virus and its transmission has become available, allowing ART activities to resume. Still, questions on the impact of the virus on human gametes and fertility remain.

OBJECTIVE AND RATIONALE

This article summarizes published data, aiming to clarify the impact of SARS-CoV-2 and the COVID-19 disease on human fertility and assisted reproduction, as well as the impact of vaccination, and from this, provide answers to questions that are relevant for people contemplating pregnancy and for health care professionals.

SEARCH METHODS

PUBMED/MEDLINE and the WHO COVID-19 database were searched from inception to 5 October 2022 with search terms focusing on 'SARS-CoV-2' and gametes, embryos, reproductive function, fertility and ART. Non-English studies and papers published prior to 2020 were excluded, as well as reviews and non-peer reviewed publications. Full papers were assessed for relevance and quality, where feasible.

OUTCOMES

From the 148 papers included, the following observations were made. The SARS-CoV-2-binding proteins, angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine protease (TMPRSS2), are expressed in the testis, but co-expression remains to be proven. There is some evidence of SARS-CoV-2 RNA in the ejaculate of COVID-19 patients with severe disease, but not in those with mild/moderate disease. SARS-CoV-2 infection can impair spermatogenesis, but this seems to resolve after one spermatogenic cycle. Testosterone levels seem to be lower during and after COVID-19, but long-term data are lacking; disease severity may be associated with testosterone levels. COVID-19 cannot be considered a sexually transmitted disease. There is no co-expression of ACE2 and TMPRSS2 in the myometrium, uterus, ovaries or fallopian tubes. Oocytes seem to have the receptors and protease machinery to be susceptible to SARS-CoV-2 infection; however, viral RNA in oocytes has not been detected so far. Women contemplating pregnancy following COVID-19 may benefit from screening for thyroid dysfunction. There is a possible (transient) impact of COVID-19 on menstrual patterns. Embryos, and particularly late blastocysts, seem to have the machinery to be susceptible to SARS-CoV-2 infection. Most studies have not reported a significant impact of COVID-19 on ovarian reserve, ovarian function or follicular fluid parameters. Previous asymptomatic or mild SARS-CoV-2 infection in females does not seem to negatively affect laboratory and clinical outcomes of ART. There are no data on the minimum required interval, if any, between COVID-19 recovery and ART. There is no evidence of a negative effect of SARS-CoV-2 vaccination on semen parameters or spermatogenesis, ovarian function, ovarian reserve or folliculogenesis. A transient effect on the menstrual cycle has been documented. Despite concerns, cross reactivity between anti-SARS-CoV-2 spike protein antibodies and Syncytin-1, an essential protein in human implantation, is absent. There is no influence of mRNA SARS-CoV-2 vaccine on patients' performance during their immediate subsequent ART cycle. Pregnancy rates post-vaccination are similar to those in unvaccinated patients.

WIDER IMPLICATIONS

This review highlights existing knowledge on the impact of SARS-CoV-2 infection or COVID-19 on fertility and assisted reproduction, but also identifies gaps and offers suggestions for future research. The knowledge presented should help to provide evidence-based advice for practitioners and couples contemplating pregnancy alike, facilitating informed decision-making in an environment of significant emotional turmoil.