Testicular pathology in fatal COVID-19: A descriptive autopsy study

Effect of SARS-CoV-2 infection on sperm telomere length

PURPOSE

The repercussions and outcomes of the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has raised concerns about potential adverse effects on the male reproductive system. Telomeres are crucial in maintaining the integrity and stability of genomic DNA, and viral infections can induce changes in telomere biology. In this study, the repercussions of SARS-CoV-2 infection in male reproductive health were analyzed.

METHODS

This case-control study enrolled subjects who donated blood and semen samples. Fifty-six men with and 56 without prior COVID-19 infection, ages 18-45 years, were included. Semen analysis and hormonal levels were evaluated. The presence of SARS-CoV-2 RNA in semen and the sperm telomere length were assessed by quantitative polymerase chain reaction and associated with clinical and laboratory data. To reduce interference factors, known variables that influence telomere length were analyzed independently.

RESULTS

Sperm telomere length was significantly diminished in the COVID-19 positive group with a mean difference of 0.635 compared to the negative group (p = 0.041). Most individuals in the COVID-19 positive group were clinically classified as asymptomatic/mild illness, and all samples were collected more than 90 days after recovery. No statistically significant differences were observed between the groups in terms of clinical data, semen parameters, and serum levels of follicle-stimulation hormone, estradiol, and testosterone. Persistent or subgenomic SARS-CoV-2 RNA was not detected in the semen samples.

CONCLUSION

This study revealed that SARS-CoV-2 infection reduced sperm telomere length without alterations in semen parameters or hormonal levels. These results provide further evidence that SARS-CoV-2 infection can induce genomic alterations in human sperm.

Long COVID: Pathophysiology, current concepts, and future directions

Long COVID, an umbrella term referring to a variety of symptoms and clinical presentations that emerges in a subset of patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has a significant effect on quality of life and places a substantial burden on health care systems worldwide, straining financial and human resources. The pathophysiology of long COVID remains incompletely understood, though several hypotheses have been proposed to explain different aspects of this complex condition. SARS-CoV-2 persistence, direct organ damage, innate and adaptive immune system perturbation, autoimmunity, latent virus reactivation, endothelial dysfunction, and microbiome disturbances are among the most relevant avenues for elucidating the evolution, complexity, and mechanisms of long COVID. Active investigation regarding potential biomarkers for long COVID and its associated disease endotypes highlights the role of inflammatory mediators, immunophenotyping, and multiomics approaches. Further advances in understanding long COVID are needed to inform current and future therapeutics.

SARS-CoV-2-induced cytokine storm drives prolonged testicular injury and functional impairment in mice that are mitigated by dexamethasone

Compromised male reproductive health, including reduced testosterone and sperm count, is one of the long COVID symptoms in individuals recovering from mild-severe disease. COVID-19 patients display testicular injury in the acute stage and altered serum fertility markers in the recovery phase, however, long-term implications on the testis remain unknown. This study characterized the consequences of SARS-CoV-2 on testis function. The K18-hACE2 mice that survived SARS-CoV-2 infection were followed for one month after infection and the testicular injury and function markers were assessed at different stages of infection and recovery. The long-term impact of infection on key testes function-related hormones and male fertility was measured. The efficacy of inflammation-suppressing drug in preventing testicular injury was also evaluated. The morphological defects like sloughing of spermatids into the lumen and increased apoptotic cells sustained for 2-4 weeks after infection and correlated with testicular inflammation and immune cell infiltration. Transcriptomic analysis revealed dysregulation of inflammatory, cell death, and steroidogenic pathways. Furthermore, reduced testosterone levels associated with a transient reduction in sperm count and male fertility. Most testicular impairments resolved within one month of infection. Importantly, dexamethasone treatment attenuated testicular damage, inflammation, and immune infiltration. Our results implicate virus-induced cytokine storm as the major driver of testicular injury and functional impairments, timely prevention of which limits testis damage. These findings serve as a model for evaluating therapeutics in long COVID patients and may guide clinical strategies to improve male reproductive health outcomes post-SARS-CoV-2 infection.

A Comprehensive Bibliometric Analysis of Orchitis Research from 1980 to 2023

Orchitis, an inflammation of the testes, presents significant implications for male fertility and has been a focal area of scientific inquiry over the past four decades. This study employs a comprehensive bibliometric analysis to assess the progression of global research on orchitis from 1980 to 2023. Drawing from a dataset of 1586 publications indexed in the Web of Science Core Collection, we uncover emerging patterns, collaborations, and pivotal works that have shaped the field. The United States, China, and Germany emerge as leading contributors, while the Journal of Urology stands out as a primary publishing avenue. The results highlight the increasing recognition of autoimmune responses, alongside infectious agents, as key contributors to orchitis. Moreover, molecules such as TNF-α, IL-6, and IFN-γ are identified as central to the disease's pathology. The dynamic interplay of testosterone and regulatory T cells is underscored as a determinant of the testicular immune milieu. Notably, disruptions in the blood-testis barrier (BTB) and germ cell apoptosis emerge as pivotal consequences of the condition. This analysis underscores the expansive and multidisciplinary nature of orchitis research, revealing a consistent growth in collaborative endeavors. In summary, our findings catalog the evolution of orchitis research, providing a consolidated perspective on past achievements and signposting future research avenues. Such insights are instrumental for researchers aiming to navigate the complexities of orchitis and its multifaceted impact on male reproductive health.

Testicular immunity

The testis is a unique environment where immune responses are suppressed to allow the development of sperm that possess autoimmunogenic antigens. There are several contributors responsible for testicular immune privilege, including the blood-testis barrier, testicular immune cells, immunomodulation by Sertoli cells, and high levels of steroid hormones. Despite multiple mechanisms in place to regulate the testicular immune environment, pathogens that disrupt testicular immunity can lead to long-term effects such as infertility. If testicular immunity is disturbed, autoimmune reactions can also occur, leading to aberrant immune cell infiltration and subsequent attack of autoimmunogenic germ cells. Here we discuss cellular and molecular factors underlying testicular immunity and how testicular infection or autoimmunity compromise immune privilege. We also describe infections and autoimmune diseases that impact the testis. Further research into testicular immunity will reveal how male fertility is maintained and will help update therapeutic strategies for infertility and other testicular disorders.

Interferon epsilon is produced in the testis and protects the male reproductive tract against virus infection, inflammation and damage

The testis is a reservoir for viruses that can cause persistent infection and adversely affect male reproductive health, an observation commonly attributed to deficiencies in inducible antiviral defence mechanisms. In this study, we demonstrate that interferon-epsilon (IFNε), a type I interferon initially discovered in female reproductive epithelia, is constitutively expressed by meiotic and post-meiotic spermatogenic cells, Leydig cells and macrophages in mouse testes. A similar distribution pattern was observed in human testes. Mice lacking IFNɛ were more susceptible to Zika virus-induced inflammation and damage of the testis and epididymis compared to wild-type mice. Exogenous IFNε treatment reduced the viral infection burden in cultured human testicular cells by inducing interferon-stimulated gene expression, and reducing inflammatory gene expression and cell damage. Treatment was more effective when administered prior to infection. These data indicate a critical role for constitutively-expressed IFNɛ in limiting viral infection and inflammatory damage in the male reproductive tract.

Transmission electron microscopy reveals the presence of SARS-CoV-2 in human spermatozoa associated with an ETosis-like response

BACKGROUND

Severe acute syndrome coronavirus 2 can invade a variety of tissues, including the testis. Even though this virus is scarcely found in human semen polymerase chain reaction tests, autopsy studies confirm the viral presence in all testicular cell types, including spermatozoa and spermatids.

OBJECTIVE

To investigate whether the severe acute syndrome coronavirus 2 is present inside the spermatozoa of negative polymerase chain reaction-infected men up to 3 months after hospital discharge.

MATERIALS AND METHODS

This cross-sectional study included 13 confirmed moderate-to-severe COVID-19 patients enrolled 30-90 days after the diagnosis. Semen samples were obtained and examined with real-time polymerase chain reaction for RNA detection and by transmission electron microscopy.

RESULTS

In moderate-to-severe clinical scenarios, we identified the severe acute syndrome coronavirus 2 inside spermatozoa in nine of 13 patients up to 90 days after discharge from the hospital. Moreover, some DNA-based extracellular traps were reported in all studied specimens.

DISCUSSION AND CONCLUSION

Although severe acute syndrome coronavirus 2 was not present in the infected men's semen, it was intracellularly present in the spermatozoa till 3 months after hospital discharge. The Electron microscopy (EM) findings also suggest that spermatozoa produce nuclear DNA-based extracellular traps, probably in a cell-free DNA-dependent manner, similar to those previously described in the systemic inflammatory response to COVID-19. In moderate-to-severe cases, the blood-testes barrier grants little defence against different pathogenic viruses, including the severe acute syndrome coronavirus 2. The virus could also use the epididymis as a post-testicular route to bind and fuse to the mature spermatozoon and possibly accomplish the reverse transcription of the single-stranded viral RNA into proviral DNA. These mechanisms can elicit extracellular cell-free DNA formation. The potential implications of our findings for assisted conception must be addressed, and the evolutionary history of DNA-based extracellular traps as preserved ammunition in animals' innate defence might improve our understanding of the severe acute syndrome coronavirus 2 pathophysiology in the testis and spermatozoa.

Toosi B, Ghorbanifaraz P, Mahmoudiasl GR, Aliaghaei A, Faghihi Hosseinabadi H, Paktinat S, Abdollahifar MA. Vimentin as a contributing factor in SARS-CoV-2-induced orchitis on postmortem testicular autopsy of COVID-19 cases: A case-control study

Background

Coronavirus disease 2019 (COVID-19) was identified in China in late December 2019 and led to a pandemic that resulted in millions of confirmed cases and deaths. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), uses distinct receptors and co-receptors to enter host cells. Vimentin has emerged as a potential co-receptor for SARS-CoV-2 due to the high level of vimentin expression in testis tissue.

Objective

The present study investigated the link between vimentin expression level and SARS-CoV-2-induced orchitis.

Materials and Methods

In this case-control study, testis autopsy samples were collected immediately after the death of both COVID-19 cases and a control group that included individuals who died due to accidental causes. Gene expression and immunohistochemical assays were conducted to evaluate the level of vimentin expression, cell proliferation, and leukocyte infiltration.

Results

A significant expression of vimentin and infiltration of immune cells (CD68+, CD38+, and CD138+) in the testicular tissue of COVID-19 cases, along with extensive immunoglobulin G precipitation and reduced inhibin expression (p = 0.001) were observed. Additionally, gene expression analysis revealed increased expression of vimentin and decreased expression of the proliferation markers Ki67 and proliferating cell nuclear antigen, suggesting that SARS-CoV-2 may disrupt spermatogenesis through immune responses and the arrest of cell proliferation.

Conclusion

There may be a strong link between vimentin expression and COVID-19-induced orchitis. Further studies are needed to confirm these findings. Considering some limitations, vimentin can be used as a biomarker option for testicular damage following COVID-19-induced orchitis.

The Association Between Male Viral Infections and Infertility: A Systematic Review and Meta-Analysis

Infertility affects approximately one-sixth of couples worldwide, with male factors contributing to half of all cases. However, infections, particularly those of reproductive tract, are increasingly recognized as important contributors to male infertility. Therefore, in this meta-analysis, we focused on the impact of various viral infections on male infertility. We searched PubMed, Embase, Web of Science and Cochrane Library on 20 October 2023. And included 135 studies involving 30,298 men of reproductive age. We found that the human papilloma virus (HPV)-infected group had a significantly higher DNA fragmentation index (DFI) than the non-infected group, with a mean difference (MD) of 5.64 (95% CI: 3.74-7.54). Conversely, the HPV-infected group had significantly lower sperm count, concentration, viability and normal morphology. Other viruses that affect semen quality include hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). HBV significantly decreased fertilization rate, with an odds ratio (OR) of 0.86 (95% CI: 0.76-0.99). HPV associated with lower clinical pregnancy rate (OR: 0.31 [95% CI: 0.16-0.62]) and higher miscarriage rate (OR: 5.28 [95% CI: 2.02-13.78]). Additionally, the fertility treatment group had a significantly higher rate of HPV infection (OR: 1.85 [95% CI: 1.10-3.12]) and adeno-associated virus (AAV) infection (OR: 8.49 [95% CI: 2.66-27.10]) than the fertility group. Conclusively, most viral infections affect semen quality, while HBV and HPV may affect assisted reproductive technology (ART) outcomes. HPV and AAV are risk factors for infertility.

COVID-19: a multi-organ perspective

In this mini review, we explore the complex network of inflammatory reactions incited by SARS-CoV-2 infection, which extends its reach well beyond the respiratory domain to influence various organ systems. Synthesizing existing literature, it elucidates how the hyperinflammation observed in COVID-19 patients affects multiple organ systems leading to physiological impairments that can persist over long after the resolution of infection. By exploring the systemic manifestations of this inflammatory cascade, from acute respiratory distress syndrome (ARDS) to renal impairment and neurological sequelae, the review highlights the profound interplay between inflammation and organ dysfunction. By synthesizing recent research and clinical observations, this mini review aims to provide an overview of the systemic interactions and complications associated with COVID-19, underscoring the need for an integrated approach to treatment and management. Understanding these systemic effects is crucial for improving patient outcomes and preparing for future public health challenges.

hACE2 upregulation and participation of macrophages and clear cells in the immune response of epididymis to SARS-CoV-2 in K18-hACE2 mice

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus caused the coronavirus disease 2019 pandemic, and the prevalence of deaths among men is higher than among women. The epididymis, divided into caput, corpus, and cauda, shows a region-specific immunity. The K18-hACE2 mouse expresses human angiotensin-converting enzyme 2 (hACE2), the receptor that allows SARS-CoV-2 infection. However, studies using this transgenic mouse to evaluate the impact of this viral infection in epididymis have not yet been performed.

OBJECTIVES

We evaluated the expression of hACE2 in the epididymis of SARS-CoV-2-infected K18-hACE2 mice, and assessed the epididymal immune response, focusing on F4/80+ mononuclear phagocytes and tumor necrosis factor-alpha expression.

MATERIALS AND METHODS

The following analyses were performed in the epididymal sections of infected mice: epithelial height and duct diameter, birefringent collagen, Terminal deoxynucleotidyl Transferase-mediated dUTP Nick End Labelling, immunoreactions for detection of hACE2, spike, FGF, V-ATPase, F4/80, tumor necrosis factor-alpha, and iNOS. Viral particles were identified under electron microscopy. hACE2, Rigi, Tgfb1 and Tnfa expression were also evaluated by real-time quantitative polymerase chain reaction.

RESULTS

All epididymal regions expressed hACE2, which increased in all epididymal regions in the infected mice. However, the caput appeared to be the most infected region. Despite this, the caput region showed minimal changes while the cauda showed significant epithelial changes associated with increased iNOS immunoexpression. The F4/80+ mononuclear phagocyte area increased significantly in both stroma and epithelium. In addition to the epithelial and stromal mononuclear phagocytes, tumor necrosis factor-alpha was also detected in clear cells, whose cytoplasm showed a significant increase of this cytokine in the infected animals.

DISCUSSION AND CONCLUSION

The K18-hACE2 mouse is a useful model for evaluating the impact of SARS-CoV-2 infection in the epididymis. The infection induced hACE2 upregulation, favoring the virulence in the epididymis. The epididymal regions responded differentially to infection, and the activation of F4/80+ mononuclear phagocytes associated with the increased tumor necrosis factor-alpha immunolabeling in clear cells indicates a role of clear cells/mononuclear phagocytes immunoregulatory mechanisms in the epididymal immune response to SARS-CoV-2 infection.

Can serum 17-hydroxy progesterone predict an improvement in semen parameters following micro-varicocelectomy? A prospective study

BACKGROUND & OBJECTIVES

Notably, 17-hydroxy progesterone (17-OHP) (17-OHP) is a precursor for testosterone (T) synthesis, and intratesticular testosterone (ITT) is essential for spermatogenesis. Varicocele (Vx) has an estimated prevalence of 15% in the general population and 35% in those with primary infertility. We aimed to evaluate the correlation between changes of serum 17-OHP after sub-inguinal micro-varicocelectomy and improvement of semen parameters.

PATIENTS AND METHODS

The current prospective study included 45 infertile men attending the andrology clinic form February 2021 to August 2021. Two semen analyses and hormonal profile were evaluated. Colored duplex ultasonography (CDUS) was done in standing and supine position for accurate measurements of testicular volumes and confirmation of Vx. Patients underwent sub-inguinal micro-varicocelectomy using a surgical microscope HB surgitech. We followed them prospectively up for three months following micro-varicocelectomy with serum TT and 17-OHP.

RESULTS

Sperm concentration improved significantly from 8.36 ± 5.04 million/ml to 12.52 ± 8.42 million/ml after 3 months following sub-inguinal micro-varicocelectomy (p= 0.001), with normalization of concentration in 15/45 (33%) patients. Total motility did not improve significantly but progressive motility improved significantly from 8.62 ± 8.74% to 16.24 ± 14.45% (p=0.001). Abnormal forms significantly declined from 96.67 ± 2.03% to 95.75 ± 2.47% (p=0.009).  Serum 17 OHP and 17 OHP/total testosterone (TT) improved significantly from 1.21 ± 0.45 ng/ml and 0.26 ± 0.09 to 1.42 ± 0.76 ng/ml and 0.3 ± 0.16 (p= 0.013, p= 0.004), respectively, while serum TT did not improve significantly. A significant correlation was found between improvement in sperm concentration and both serum 17 OHP and 17 OHP/TT ratio (p=0.001, p=004). Furthermore, change in abnormal sperm forms showed significant correlations with changes in both 17-OHP and 17-OHP/TT.

CONCLUSION

17 OHP and 17OHP/ TT ratio can be used as biomarkers to detect improvement in semen parameters following sub-inguinal micro-varicocelectomy.

CD147 mediates S protein pseudovirus of SARS-CoV-2 infection and its induction of spermatogonia apoptosis

Male cases diagnosed COVID-19 with more complications and higher mortality compared with females, and the overall consequences of male sex hormones and semen parameters deterioration were observed in COVID-19 patients, whereas the involvement and mechanism for spermatogenic cell remains unclear. The study was aimed to investigate the infection mode of S protein (D614G) pseudovirus (pseu-S-D614G) to spermatogenic cells, as well as the influence on cell growth. Both mouse spermatogonia (GC-1 cell, immortalized spermatogonia) and spermatocyte (GC-2 cell, immortalized spermatocytes) were used to detect the infection of pseu-S-D614G of SARS-CoV-2, and further explored the effect of SARS-CoV-2-spike protein (S-protein) and SARS-CoV-2-spike protein (omicron) (O-protein) on GC-1 cell apoptosis and proliferation. The data showed that the pseu-S-D614G invaded into GC-1 cells through either human ACE2 (hACE2) or human CD147 (hCD147), whereas GC-2 cells were insensitive to viral infection. In addition, the apoptosis and proliferation suppression inflicted by S-protein and O-protein on GC-1 cells was through Bax-Caspase3 signaling rather than arresting cell cycle progression. These findings suggest that CD147, apart from ACE2, may be a potential receptor for SARS-CoV-2 infection in testicular tissues, and that the apoptotic effect was induced in spermatogonia cells by S-protein or O-protein, eventually resulted in the damage to male fertility.

Correlation between viral infections in male semen and infertility: a literature review

Infertility affects approximately one-sixth of couples globally, with the incidence of male infertility steadily increasing. However, our understanding of the impact of viral infections on fertility remains limited. This review consolidates findings from previous studies, outlining 40 viruses identified in human semen and summarizing their key characteristics, modes of transmission, and their effects on both the reproductive and endocrine systems. Furthermore, it elucidates potential pathogenic mechanisms and treatment prospects of viruses strongly associated with male infertility. This synthesis will enhance our comprehension of how viral infections influence male reproductive health, offering valuable insights for future research as well as the diagnosis and treatment of infectious infertility.

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.

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.

Systematic analyses of the factors influencing sperm quality in patients with SARS-CoV-2 infection

To figure out how does SARS-CoV-2 affect sperm parameters and what influencing factors affect the recovery of sperm quality after infection? We conducted a prospective cohort study and initially included 122 men with SARS-CoV-2 infection. The longest time to track semen quality after infection is 112 days and 58 eligible patients were included in our study eventually. We subsequently exploited a linear mixed-effects model to statistically analyze their semen parameters at different time points before and after SARS-CoV-2 infection. Semen parameters were significantly reduced after SARS-CoV-2 infection, including total sperm count (211 [147; 347] to 167 [65.0; 258], P < 0.001), sperm concentration (69.0 [38.8; 97.0] to 51.0 [25.5; 71.5], P < 0.001), total sperm motility (57.5 [52.3; 65.0] to 51.0 [38.5; 56.8], P < 0.001), progressive motility (50.0 [46.2; 58.0] to 45.0 [31.5; 52.8], P < 0.001). The parameters displayed the greatest diminution within 30 days after SARS-CoV-2 infection, gradually recovered thereafter, and exhibited no significant difference after 90 days compared with prior to COVID-19 infection. In addition, the patients in the group with a low-grade fever showed a declining tendency in semen parameters, but not to a significant degree, whereas those men with a moderate or high fever produced a significant drop in the same parameters. Semen parameters were significantly reduced after SARS-CoV-2 infection, and fever severity during SARS-CoV-2 infection may constitute the main influencing factor in reducing semen parameters in patients after recovery, but the effect is reversible and the semen parameters gradually return to normal with the realization of a new spermatogenic cycle.

Comprehensive evaluation of inactivated SARS-CoV-2 vaccination on sperm parameters and sex hormones

Background

The inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine has made significant contributions to fighting the epidemic in the past three years. However, the rapid development and application raised concerns about its safety in reproductive health, especially after several studies had observed a decrease in semen parameters following two doses of mRNA SARS-CoV-2 vaccination. Thus, it is necessary to comprehensively evaluate the effect of inactivated SARS-CoV-2 vaccine on male fertility.

Methods

A retrospective cohort study was conducted in the Center for Reproductive Medicine of the Affiliated Hospital of Jining Medical University between July 2021 and March 2023. A total of 409 men with different vaccination status and no history of SARS-CoV-2 infection were included in this study. Their sex hormone levels and semen parameters were evaluated and compared separately.

Results

The levels of FSH and PRL in one-dose vaccinated group were higher than other groups, while there were no significant changes in other sex hormone levels between the control and inactivated SARS-CoV-2 vaccinated groups. Most semen parameters such as volume, sperm concentration, total sperm count, progressive motility and normal forms were similar before and after vaccination with any single dose or combination of doses (all P > 0.05). Nevertheless, the total motility was significantly decreased after receiving the 1 + 2 doses of vaccine compared to before vaccination (46.90 ± 2.40% vs. 58.62 ± 2.51%; P = 0.001). Fortunately, this parameter was still within the normal range.

Conclusion

Our study demonstrated that any single dose or different combined doses of inactivated SARS-CoV-2 vaccination was not detrimental to male fertility. This information could reassure men who want to conceive after vaccination and be incorporated into future fertility recommendations.

Updates in the pathophysiology of COVID-19 infection in male reproductive and sexual health: a literature review

This extensive comprehensive review explores the impact of the Coronavirus disease 2019 (COVID-19) pandemic on men's sexual and reproductive health. We conducted a literature review focusing on the possible pathophysiology by which severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) affects men's sexual and reproductive systems. We reviewed most of the studies that reported the impact of SARS-CoV-2 infection on the Testicular, Epididymal, Prostatic, and Penile tissue. Also, we focused on evaluating the SARS-CoV-2 infection on semen parameters and male reproductive hormones. Finally, we reviewed the COVID-19 vaccine's effect on male reproductive and sexual health. Findings revealed the adverse consequences of SARS-CoV-2 at cellular and organ levels on the male genital tract. However, the reported data are still controversial. The initial data regarding COVID-19 vaccination was promising promoted safety for men's reproductive and sexual health. We conclude this paper by offering recommendations to address these adverse consequences and potentially improve sexual and reproductive health among men in the post-COVID-19 pandemic era.

SARS-CoV-2 vaccination and semen quality: a study based on sperm donor candidate data in southwest China

Background

The coronavirus disease 2019 (COVID-19) pandemic has been a global health crisis and continues to pose risk to population health at the present. Vaccination against this disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a public health priority worldwide. Yet, limited information is available on the potential impact of such vaccines on human fertility.

Methods

To examine the relationship between COVID-19 vaccination and male fertility, we conducted an observational study on sperm donor candidates in China who received Chinese COVID-19 vaccines between January 1, 2020 to December 31, 2021.

Results

A total of 2,955 semen samples from 564 individuals were assessed along with vaccination information. Statistical analyses were conducted on both the entire study population and the subgroup of individuals who provided repeated semen samples before and after vaccination. While motility related parameters [progressive rate, curvilinear velocity (VCL), average path velocity (VAP), straight-line velocity (VSL), wobble (WOB), straightness (STR), linearity (LIN), amplitude of lateral head displacement (ALH), beat-cross frequency (BCF)] exhibited statistically significant difference before and after vaccination based on Welch two-sample test, mixed effects regression results based on repeated measures from the same individuals indicated that vaccination was not statistically associated with sperm quality parameters except for VCL, VAP, and VSL. Individual variability was the key determinant of sperm quality variance, with contribution ranging from 19% to 82%.

Conclusions

Findings from our study could help to enhance current understanding of male reproductive health in the context of the global pandemic.

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.

The impact of Sars-Cov-2 infection on the wound healing of cervical treatment in patients with squamous intraepithelial lesions: a retrospective cohort study

Objective

SARS-CoV-2 infection has been associated with an increase in inflammatory factors, a weakening of the immune system, and a potentially delay in wound healing following surgery or ablative treatment. In this retrospective cohort study, we aimed to investigate the impact of SARS-CoV-2 infection on wound healing following cervical treatment in patients with squamous intraepithelial lesions (SIL).

Method

From November 2022 to February 2023, patients with SIL who underwent cervical ablative treatment or loop electrosurgical excision procedure at the People's Hospital of Guangxi Zhuang Autonomous Region, China, were enrolled in the study. Of these, 29 patients who developed symptoms of SARS-CoV-2 infection and confirmed by an antigen test within one month after cervical treatment were included as experimental group, while the other 31 patients who received cervical treatment after recovering from SARS-CoV-2 infection were included in the control group. The cervical wound condition of all patients was documented using colposcopy immediately and one month after the procedure. Image J software was utilized to analyze the wound healing rate at one month post-treatment, and the wound healing status between two groups was compared. A vaginal discharge examination was performed before and one month after cervical treatment.

Results

No significant differences in age, severity, treatment, or time between groups. Experimental group had significantly lower healing rate 83.77(62.04, 97.09) % than control 98.64(97.10, 99.46)%，p < 0.001, and a higher scab non-shedding rate (24.14% vs. 3.22%, p = 0.024). Among patients who were infected with SARS-CoV-2 after undergoing cervical treatment, we observed 5 out of 7 patients (71.43%) contracted SARS-CoV-2 within 2 weeks after cervical treatment. No significant correlation was found between white blood cell count or leukocyte esterase in vaginal discharge and delayed wound healing of the cervix (p = 0.947 and 0.970, respectively).

Conclusion

SARS-CoV-2 infection may prolong the healing time of cervical treatment in patients with SIL. To minimize the risk of delayed healing, it's crucial for patients to avoid viral infections such as SARS-CoV-2 within the first month of treatment. Taking necessary precautions to prevent infection is essential for successful cervical treatment outcomes in patients with SIL.

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.

From Emergence to Endemicity: A Comprehensive Review of COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), later renamed coronavirus disease 2019 (COVID-19), was first identified in Wuhan, China, in early December 2019. Initially, the China office of the World Health Organization was informed of numerous cases of pneumonia of unidentified etiology in Wuhan, Hubei Province at the end of 2019. This would subsequently result in a global pandemic with millions of confirmed cases of COVID-19 and millions of deaths reported to the WHO. We have analyzed most of the data published since the beginning of the pandemic to compile this comprehensive review of SARS-CoV-2. We looked at the core ideas, such as the etiology, epidemiology, pathogenesis, clinical symptoms, diagnostics, histopathologic findings, consequences, therapies, and vaccines. We have also included the long-term effects and myths associated with some therapeutics of COVID-19. This study presents a comprehensive assessment of the SARS-CoV-2 virology, vaccines, medicines, and significant variants identified during the course of the pandemic. Our review article is intended to provide medical practitioners with a better understanding of the fundamental sciences, clinical treatment, and prevention of COVID-19. As of May 2023, this paper contains the most recent data made accessible.

COVID-19: detection methods in post-mortem samples

COVID-19 identification is routinely performed on fresh samples, such as nasopharyngeal and oropharyngeal swabs, even if, the detection of the virus in formalin-fixed paraffin-embedded (FFPE) autopsy tissues could help to underlie mechanisms of the pathogenesis that are not well understood.

The gold standard for COVID-19 detection in FFPE samples remains the qRT-PCR as in swab samples, contextually other methods have been developed, including immunohistochemistry (IHC), and in situ hybridization (ISH). In this manuscript, we summarize the main data regarding the methods of COVID-19 detection in pulmonary and extra-pulmonary post-mortem samples, and especially the sensitivity and specificity of these assays will be discussed.

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.

Evaluation of semen DNA integrity and related parameters with COVID-19 infection: a prospective cohort study

BACKGROUND

In the context of Corona Virus Disease 2019 (COVID-19) global pandemic, Its impact on male reproductive function should be concerned.

METHODS

Our study is a prospective cohort study that recruited participants infected or uninfected with COVID-19 between December 2022 and March 2023. All laboratory tests and questionnaire data were completed at the First Affiliated Hospital of Nanchang University. A total of 132 participants were enrolled, with 78 COVID-19 positive patients as the positive group and 54 COVID-19 negative participants as the negative group. Semen quality was assessed by the fifth World Health Organization criteria. The general characteristics of semen samples were assessed using CASA (computer-assisted sperm analysis). DNA damage and the high density stainability was assessed by sperm chromatin structure analysis (SCSA) based on flowcytometry.

RESULTS

The sperm concentration, progressive motility and motility in COVID-19 negative group were significantly higher than positive group. In the following DNA damage analysis, a remarkably lower sperm DNA fragmentation index (DFI) in the COVID-19 negative group. In the positive group, unhealthy lifestyles had no significant effect on semen parameters, DNA fragmentation and nuclear compaction.

CONCLUSIONS

After excluding the interference of unhealthy lifestyle, the COVID-19 infection can have a significant impact on the quality of semen, especially the DFI,. Therefore, it shows that COVID-19 can adversely affects male fertility, and this result provides advisory guidance for clinicians.

Evidence for residual SARS-CoV-2 in corpus cavernosum of patients who recovered from COVID-19 infection

BACKGROUND

The COVID-19 is an ongoing health problem with millions of cases and deaths worldwide. Although the virus is transmitted with droplets through the respiratory system, the involvement of different organs has been reported.

OBJECTIVES

The pandemic caused urological procedures to be postponed when patient is infected with SARS-CoV-2. However, the reliability of 1 month postpone period and long-term complications of the virus, such as a possible erectile dysfunction (ED) is not clarified. We aimed to compare the corpus cavernosum of patients 1 and 7 months after COVID-19 infection with control patients who had not COVID-19 and search for SARS-CoV-2 in tissues using immunohistochemistry and electron microscopy.

MATERIALS AND METHODS

Three groups of subjects underwent penile prosthesis implantation and Nesbit procedure for Peyronie's disease 1 and 7 months after COVID-19 infection and control group without previous COVID-19 infection. We searched for SARS-CoV-2 in penile tissue using RT-PCR, electron microscopy and immunohistochemistry.

RESULTS

Electron microscopy and immunohistochemical staining showed SARS CoV-2 virus in the penile corpus cavernosum of patients 1 month after COVID-19 recovery. Immunohistochemical staining intensity correlated with the severity of previous infection. Transmission electron microscopy revealed intracellular virtual particles of about 80 nm with a typical morphology of prominent spikes and electron-dense dots of nucleocapsid in addition to vesicles filled with virus-like particles. Cells showed increased membrane trafficking. The 1 month after COVID-19 group showed an increased number of fibroblasts. The 7 months after COVID-19 group had similar morphology and immunoreactivity as control group.

DISCUSSION

This is the first study of late post-COVID examination of penis and the second study of early post-COVID examination of corpus cavernosum. For 1 month post-COVID patients, the aetiology of ED could be the viral infection that is also affecting corpora cavernosa. We hypothesize that viral infection affects the endocytic and exocytic pathways, hence the metabolic activity of cells that can be the reason of altered functions in some post-COVID patients.

CONCLUSION

This study is important because it did not detect any virus residue in the tissue samples at the seventh month. In addition, we can say that the penile surgeries should be postponed more than 1 month after the COVID infection according to this study. But, there is a need for new studies with large series and high levels of evidence that can show how long the virus remains in the corpus cavernosum. Patients should be followed in this respect.

Comparison of semen parameters in the same patients before and after diagnosis of COVID-19

Clinical and histopathological evidence suggest that the male reproductive system may be negatively impacted in patients with coronavirus disease (COVID-19). The objective of this study is to investigate the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on semen parameters by comparing semen analyses before and after COVID-19 diagnosis in the same patient. We retrospectively analyzed 342 semen analyses by reviewing medical records. The study included two groups of patients: (i) those who underwent two consecutive semen analyses within 6 months, one before (n = 114) and one after (n = 114) COVID-19 diagnosis, and (ii) a control group (n = 114) that was age-matched and did not receive a diagnosis of COVID-19. The study results indicated a significant decrease in semen volume, total sperm count per ejaculate, progressive motile sperm count, total motile sperm count, and normal sperm morphology after SARS-CoV-2 infection in comparison to their respective values before the infection. Subgroup analyses showed that the duration of COVID-19 diagnosis (short-term vs. long-term) did not impact the changes in semen parameters. However, fever during the COVID-19 process had a negative effect on semen parameters, particularly sperm concentration, unlike in patients without fever. In conclusion, our findings suggest that SARS-CoV-2 infection is associated with a decline in semen quality, which may potentially impact male fertility. Furthermore, it's important to note that the negative effects on semen parameters may persist in the long-term. Our results also indicate that fever during active infection could be a significant risk factor that negatively affects spermatogenesis.

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.

Identification of PDCL2 as a candidate marker in Sertoli cell-only syndrome by chromatin immunoprecipitation-sequencing and bioinformatics analysis

BACKGROUND

Sertoli cell-only syndrome (SCOS) or germ cell aplasia is one of the most serious histopathological subtypes within the scope of non-obstructive azoospermia (NOA). Understanding the molecular mechanism of SCOS and identifying new non-invasive markers for clinical application is crucial to guide proper sperm procurement and avoid unnecessary interventions. This study sought to identify the differentially expressed genes (DEGs) of SCOS by using gene sequencing identity and verify the key marker genes to provide basic data for subsequent research on SCOS.

METHODS

A total of 50 testicular samples were collected in this study from 25 patients with SCOS and 25 patients with normal spermatogenesis. In total, 5 pairs of testis samples were used for the RNA-sequencing (RNA-seq). We identified the DEGs between the SCOS and normal spermatogenesis patients and conducted a Gene Ontology (GO) analysis and a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The expression of the main target gene phosducin-like 2 (PDCL2) was examined by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC).

RESULTS

In total, 3,133 upregulated DEGs and 1,406 downregulated DEGs were identified by the RNA-seq. The highly enriched processes involved in spermatogenesis included the mitotic cell cycle, cell cycle, and oocyte maturation. The expression of PDCL2 was verified as a downregulation marker in SCOS by qRT-PCR and IHC.

CONCLUSIONS

This study identified the DEGs of SCOS, and the bioinformatics analysis results identified the potential target key genes and pathways for SCOS. PDCL2 is a key gene involved in SCOS and may serve as a non-invasive downregulation marker of SCOS.

Viruses, bacteria and parasites: infection of the male genital tract and fertility

BACKGROUND

Infertility affects one couple out of six worldwide. Male infertilty can result from congenital or acquired factors, of which pathogens that reach the genital tract through sexual contact or blood dissemination. The impact of major viral, bacterial and parasitic infections on the male genital tract and fertility has been summarized.

RESULTS AND CONCLUSIONS

A systematic review of articles published in the Google Scholar and PubMed databases was conducted. It turns out that viruses, as well as bacteria and parasites are major inducers of male genital tract infections and ensuing infertility through damage to the organs and subsequent loss of function and/or through direct damage to the sperm cells. Moreover, not only male infertility results from such infections but these can also be transmitted to women and even to the offspring, thus highlighting the need to efficiently detect, treat and prevent them.

Testicular pathological alterations associated with SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the etiologic agent of the coronavirus disease 2019 (COVID-19), which caused one of the pandemics with the highest mortalities with millions of deaths and hundreds of millions of cases to date. Due to its potential for airborne transmission, many studies have focused on SARS-CoV-2 primarily as a respiratory disease. However, the spread of SARS-CoV-2 to non-respiratory organs has been experimentally demonstrated and clinically observed. During autopsy studies, histopathological lesions, and disruption of the blood-testes barrier (BTB) have been observed in the male reproductive tract. Here, we review findings from both autopsy cases and animal models that demonstrate testicular disease due to COVID-19 and present an overview of the pathological alterations that occur in the testes resulting from SARS-CoV-2 infection and explore its potential mechanisms.

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.

SARS-CoV-2 Enters Human Leydig Cells and Affects Testosterone Production In Vitro

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a SARS-like coronavirus, continues to produce mounting infections and fatalities all over the world. Recent data point to SARS-CoV-2 viral infections in the human testis. As low testosterone levels are associated with SARS-CoV-2 viral infections in males and human Leydig cells are the main source of testosterone, we hypothesized that SARS-CoV-2 could infect human Leydig cells and impair their function. We successfully detected SARS-CoV-2 nucleocapsid in testicular Leydig cells of SARS-CoV-2-infected hamsters, providing evidence that Leydig cells can be infected with SARS-CoV-2. We then employed human Leydig-like cells (hLLCs) to show that the SARS-CoV-2 receptor angiotensin-converting enzyme 2 is highly expressed in hLLCs. Using a cell binding assay and a SARS-CoV-2 spike-pseudotyped viral vector (SARS-CoV-2 spike pseudovector), we showed that SARS-CoV-2 could enter hLLCs and increase testosterone production by hLLCs. We further combined the SARS-CoV-2 spike pseudovector system with pseudovector-based inhibition assays to show that SARS-CoV-2 enters hLLCs through pathways distinct from those of monkey kidney Vero E6 cells, a typical model used to study SARS-CoV-2 entry mechanisms. We finally revealed that neuropilin-1 and cathepsin B/L are expressed in hLLCs and human testes, raising the possibility that SARS-CoV-2 may enter hLLCs through these receptors or proteases. In conclusion, our study shows that SARS-CoV-2 can enter hLLCs through a distinct pathway and alter testosterone production.

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.

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.

Zika Virus Infection Damages the Testes in Pubertal Common Squirrel Monkeys (Saimiri collinsi)

During the Zika virus (ZIKV) outbreak and after evidence of its sexual transmission was obtained, concerns arose about the impact of the adverse effects of ZIKV infection on human fertility. In this study, we evaluated the clinical-laboratory aspects and testicular histopathological patterns of pubertal squirrel monkeys (Saimiri collinsi) infected with ZIKV, analyzing the effects at different stages of infection. The susceptibility of S. collinsi to ZIKV infection was confirmed by laboratory tests, which detected viremia (mean 1.63 × 106 RNA copies/µL) and IgM antibody induction. Reduced fecal testosterone levels, severe testicular atrophy and prolonged orchitis were observed throughout the experiment by ultrasound. At 21 dpi, testicular damage associated with ZIKV was confirmed by histopathological and immunohistochemical (IHC) analyses. Tubular retraction, the degeneration and necrosis of somatic and germ cells in the seminiferous tubules, the proliferation of interstitial cells and an inflammatory infiltrate were observed. ZIKV antigen was identified in the same cells where tissue injuries were observed. In conclusion, squirrel monkeys were found to be susceptible to the Asian variant of ZIKV, and this model enabled the identification of multifocal lesions in the seminiferous tubules of the infected group evaluated. These findings may suggest an impact of ZIKV infection on male fertility.

High SARS-CoV-2 tropism and activation of immune cells in the testes of non-vaccinated deceased COVID-19 patients

BACKGROUND

Cellular entry of SARS-CoV-2 has been shown to rely on angiotensin-converting enzyme 2 (ACE2) receptors, whose expression in the testis is among the highest in the body. Additionally, the risk of mortality seems higher among male COVID-19 patients, and though much has been published since the first cases of COVID-19, there remain unanswered questions regarding SARS-CoV-2 impact on testes and potential consequences for reproductive health. We investigated testicular alterations in non-vaccinated deceased COVID-19-patients, the precise location of the virus, its replicative activity, and the immune, vascular, and molecular fluctuations involved in the pathogenesis.

RESULTS

We found that SARS-CoV-2 testicular tropism is higher than previously thought and that reliable viral detection in the testis requires sensitive nanosensors or RT-qPCR using a specific methodology. Through an in vitro experiment exposing VERO cells to testicular macerates, we observed viral content in all samples, and the subgenomic RNA's presence reinforced the replicative activity of SARS-CoV-2 in testes of the severe COVID-19 patients. The cellular structures and viral particles, observed by transmission electron microscopy, indicated that macrophages and spermatogonial cells are the main SARS-CoV-2 lodging sites, where new virions form inside the endoplasmic reticulum Golgi intermediate complex. Moreover, we showed infiltrative infected monocytes migrating into the testicular parenchyma. SARS-CoV-2 maintains its replicative and infective abilities long after the patient's infection. Further, we demonstrated high levels of angiotensin II and activated immune cells in the testes of deceased patients. The infected testes show thickening of the tunica propria, germ cell apoptosis, Sertoli cell barrier loss, evident hemorrhage, angiogenesis, Leydig cell inhibition, inflammation, and fibrosis.

CONCLUSIONS

Our findings indicate that high angiotensin II levels and activation of mast cells and macrophages may be critical for testicular pathogenesis. Importantly, our findings suggest that patients who become critically ill may exhibit severe alterations and harbor the active virus in the testes.

COVID-19 and its treatments: lights and shadows on testicular function

PURPOSE

The SARS-CoV-2 pandemic has rapidly spread worldwide and, among the others, the male gender was quickly recognized as an independent risk factor for both the disease and its consequences. Since the possibility of long-term hormonal axis changes and male gamete impairment have been hypothesized but a relatively low levels of evidence has been reached, we focused this narrative mini-review on summarizing key state-of-the-art knowledge on male reproductive effects of COVID-19 as a quick reference for reproductive health specialists.

METHODS

A comprehensive Medline/PubMed and Embase search was performed selecting all relevant, peer-reviewed papers in English published from 2020. Other relevant papers were selected from the reference lists.

RESULTS

Available evidence indicates that the likelihood of direct testicular damage from SARS-CoV-2 is somewhat low, but there are many indirect ways (fever, cytokine imbalance, and drugs) through which the pituitary-gonadal axis and spermatogenesis may be disrupted. These alterations are probably transient, but as available evidence is low quality, it cannot be excluded that previous pathologies or comorbidities might modulate the risk of their persistence. On the other hand, available evidence shows high safety regarding andrological health for available vaccines, although studies are mainly focused on mRNA vaccines.

CONCLUSION

A careful andrological evaluation of men recovering from COVID-19 is highly recommended. Since available evidence is relatively scarce, a careful andrological follow-up and counseling of these patients are mandatory.

Impact of COVID-19 on male urogenital health: Success of vaccines

Throughout 2021, the scientific and medical communities were concentrated on dealing with the acute morbidity and mortality induced by the COVID-19 pandemic due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We reviewed the present data for adverse effects of COVID-19 on the different parts of the male urogenital system during the dynamic situation of the COVID-19 pandemic. With the approval of COVID-19 vaccinations, there is a ray of hope at the end of this dark tunnel and a chance to look ahead for the management of long-term consequences in males with urogenital illness. A multidisciplinary investigation of these cases could provide information for establishing and optimizing treatment protocols.

Urological complications of COVID-19: a systematic review

PURPOSE

COVID-19 continues to be an urgent World issue. Receptors of angiotensin converting enzyme 2 (ACE2), gateway of SARS-CoV-2, are present in the lungs, bladder, prostate, and testicles. Therefore, these organs face high risk of damage caused by the virus and this mechanism may explain non-respiratory symptoms of the disease.

MATERIALS AND METHODS

This systematic review, guided by the PRIMSA statement, was proposed to elucidate possible urological complications of COVID-19. Searches were carried out in Medline (PubMed), Cochrane (CENTRAL), Embase, MedRxiv and LILACS. Bias analysis was made using the specific Newcastle-Ottawa Scale for each study design.

RESULTS

Search was carried out until April 2022, and 8,477 articles were identified. Forty-nine of them were included in this systematic review. There is evidence that lower urinary tract symptoms and acute scrotum may be signs of COVID-19 in men, although in a small proportion. Also, the disease may have a transitory impact on male fertility, evidenced by several alterations in sperm counts. However, it must be clarified whether this impact is transitory, or may last for longer periods. Several patients showed reduction of total value of testosterone. Two authors linked low levels of testosterone with worse outcomes of COVID-19, suggesting that the hormone may be used as an early biomarker of the severity of the disease. Moreover, it is extremely unlikely that SARS-CoV-2 is transmitted by semen.

CONCLUSION

This systematic review identified possible repercussions of COVID-19 in the urinary as well as in the male reproductive system.

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 failure including testicular injury 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 can likely result either from direct virus infection of resident cells or by exposure to systemic inflammatory mediators or virus antigens. We here characterized SARS-CoV-2 infection in different human testicular 2D and 3D models 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 establish a productive infection in any testicular cell types. However, exposure of STC and HTO to inflammatory supernatant from infected airway epithelial cells and COVID-19 plasma depicted a significant decrease in cell viability and death of undifferentiated spermatogonia. Further, exposure to only SARS-CoV-2 envelope protein, but not Spike or nucleocapsid proteins led to cytopathic effects on testicular cells that was dependent on the TLR2 receptor. A similar trend was observed in the K18h-ACE2 mouse model which revealed gross pathology in the absence of virus replication in the testis. Collectively, data strongly indicates that the testicular injury is not due to direct infection of SARS-CoV-2 but more likely an indirect effect of exposure to systemic inflammation 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.

COVID-19 Infections in Gonads: Consequences on Fertility?

COVID-19 may influence human fertility and sexuality in several ways. Different cell types in gonads show a constitutive expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2), which provide potential entry pathways for SARS-CoV-2. In addition to the biological effects of a COVID-19 infection on the gonads, the impact of the ongoing COVID-19 pandemic on mental health issues and sexual behavior may affect reproduction. This review summarizes the current knowledge on the influence of COVID-19 on the gonads and discusses possible consequences on human fertility. In this context, the close interaction between the hypothalamic-pituitary-adrenal axis and the hypothalamic-pituitary-gonadal axis in response to COVID-19-related stress is discussed. Some women noticed changes in their menstrual cycle during the COVID-19 pandemic, which could be due to psychological stress, for example. In addition, occasional cases of reduced oocyte quality and ovarian function are described after COVID-19 infection. In men, COVID-19 may cause a short-term decrease in fertility by damaging testicular tissue and/or impairing spermatogenesis. Moreover, decreased ratio testosterone/LH and FSH/LH in COVID-19 compared to aged-matched healthy men has been reported. Available data do not suggest any effect of the available SARS-CoV-2 vaccines on fertility. The effects of long COVID on human fertility have been reported and include cases with premature ovarian failure and oligomenorrhoea in women and erectile dysfunction in men. Despite the increasing knowledge about the effects of COVID-19 infections on human gonads and fertility, the long-term consequences of the COVID-19 pandemic cannot yet be assessed in this context.

Suppression of Pituitary Hormone Genes in Subjects Who Died From COVID-19 Independently of Virus Detection in the Gland

CONTEXT

Involvement of the pituitary gland in SARS-CoV-2 infection has been clinically suggested by pituitary hormone deficiency in severe COVID-19 cases, by altered serum adrenocorticotropic hormone (ACTH) levels in hospitalized patients, and by cases of pituitary apoplexy. However, the direct viral infection of the gland has not been investigated.

OBJECTIVE

To evaluate whether the SARS-CoV-2 genome and antigens could be present in pituitary glands of lethal cases of COVID-19, and to assess possible changes in the expression of immune-related and pituitary-specific genes.

METHODS

SARS-CoV-2 genome and antigens were searched in the pituitary gland of 23 patients who died from COVID-19 and, as controls, in 12 subjects who died from trauma or sudden cardiac death. Real-time reverse transcription polymerase chain reaction (PCR), in situ hybridization, immunohistochemistry, and transmission electron microscopy were utilized. Levels of mRNA transcripts of immune-related and pituitary-specific genes were measured by the nCounter assay.

RESULTS

The SARS-CoV-2 genome and antigens were detected in 14/23 (61%) pituitary glands of the COVID-19 group, not in controls. In SARS-CoV-2-positive pituitaries, the viral genome was consistently detected by PCR in the adeno- and the neurohypophysis. Immunohistochemistry, in situ hybridization, and transmission electron microscopy confirmed the presence of SARS-CoV-2 in the pituitary. Activation of type I interferon signaling and enhanced levels of neutrophil and cytotoxic cell scores were found in virus-positive glands. mRNA transcripts of pituitary hormones and pituitary developmental/regulatory genes were suppressed in all COVID-19 cases irrespective of virus positivity.

CONCLUSION

Our study supports the tropism of SARS-CoV-2 for human pituitary and encourages exploration of pituitary dysfunction after COVID-19.

A Systemic Review and Meta-analysis of the Effect of SARS-CoV-2 Infection on Sperm Parameters

Objective. Several studies examined the putative effects of SARS-CoV-2 infection on sperm parameters. However, the results remain controversial. In this study, we conducted the most up-to-date systematic review and meta-analysis to investigate the effect of SARS-CoV-2 infection on sperm quality in COVID-19-positive and COVID-19-negative male participants. Method. Seven databases were searched for literature released through June 10, 2022, containing estimates for the outcomes of interest. Using a random-effects model (REM) or a fixed-effects model (FEM), we analyzed the pooled results. The quality of all included studies was assessed by the Newcastle-Ottawa scale. In addition, we performed a quantitative and subgroup analysis of semen data across all included studies. Results. Fourteen studies were extracted from 10 publications, involving a total of 1174 participates for meta-analysis. Sperm parameters of 521 COVID-19 male patients and 653 controls were analyzed. In 8 case-control studies, the pooled mean difference (MD) of total sperm motility was -5.37% (95% confidence interval (CI): -8.47 to -2.28; p < 0.05 ), suggesting that total motility was significantly impaired in male COVID-19 cases. Subgroup analysis showed a significant decrease in semen volume, sperm concentration, and total motility in 238 patients with a recovery time of less than 90 days. Moreover, in the other 6 included pre- to post-COVID-19 studies, the pooled MDs of sperm concentration, total sperm count, total motility, progressive motility, and normal morphology were - 6.54 × 10 6/ml (95% CI: -10.27 to -2.81; p < 0.05 ), - 38.89 × 10 6 (95% CI: -59.20 to -18.58; p < 0.05 ), -7.21% (95% CI: -14.36 to -0.07; p < 0.05 ), -5.12% (95% CI: -8.71 to -1.53; p < 0.05 ), and -1.52% (95% CI: -2.88 to -0.16; p < 0.05 ), respectively, which indicate SARS-CoV-2 infection significantly affected these five sperm parameters. Conclusion. Our results revealed that SARS-CoV-2 infection was significantly correlated with decreased sperm quality. Of six sperm parameters, total motility and sperm concentration were the most significantly decreased parameters. These results suggest a possible negative influence of SARS-CoV-2 infection on testicular function and male fertility. Given the potential detrimental effect of SARS-CoV-2 on semen quality, male reproductive health should be monitored closely in patients with COVID-19. This trial is registered with CRD42021275823.

Male sex rather than socioeconomic vulnerability as a determinant for COVID-19 death in Sao Paulo: A population-based study

Objectives:

To determine the role of the male sex as a risk factor for coronavirus disease deaths in Sao Paulo and to what extent socioeconomic vulnerability and individual health issues can interfere in such risk.

Methods:

The primary cause of death, age, sex, comorbidities, and code of the Human Development Units of the residence of 37,583 individuals in Sao Paulo, Brazil, were obtained from the records on confirmed coronavirus disease resident hospitalizations of the city of Sao Paulo from the National Influenza Surveillance Information System. A social vulnerability index was assigned to each Human Development Unit. Using “death” as the outcome variable and sex, admission to the intensive care unit, obesity, renal and heart diseases, diabetes, and social vulnerability as confounders, the odds of death for males and females were compared via logistic regression.

Results:

The odds of death for males were 1.242 (confidence interval 95% = 1.237, 1.247) times the corresponding odds for females with the same values for all confounders. We estimated the odds of death for patients living in regions with high social vulnerability as 2.243 (CI 95% = 2.151, 2.339) times the corresponding odds of patients living in regions with very low social vulnerability with the same values of the remaining variables.

Conclusion:

The male:female death ratio by severe acute respiratory syndrome coronavirus 2 infection in Sao Paulo cannot be attributed only to comorbidities or social vulnerabilities. Our results suggest that the male sex is an independent biological risk factor for coronavirus disease death. Besides sex-specific factors, further research should focus on crucial biological factors in male sex coronavirus disease mortality.

SARS-CoV-2 Nucleocapsid Protein is Associated With Lower Testosterone Levels: An Experimental Study

The ongoing COVID-19 pandemic represents an extra burden in the majority of public and private health systems worldwide beyond the most pessimistic expectations, driving an urgent rush to develop effective vaccines and effective medical treatments against the SARS-CoV-2 pandemic. The Nucleocapsid structural viral protein is remarkably immunogenic and hugely expressed during infection. High IgG antibodies against Nucleocapsid protein (N protein) levels were detected in the serum of COVID-19 patients, confirming its pivotal antigen role for a T lymphocyte response in a vaccine microenvironment. Currently, adverse events associated with immunizations have raised some degree of concern, irrespective of its huge benefits in dealing with disease severity and decreasing mortality and morbidity. This hitherto study evaluates histological changes in rats’ testes, epididymis, prostate, and seminal vesicles and analyzes hormone levels after solely N protein inoculation. Therefore, we exposed a group of Lewis rats to weekly injections of the recombinant N protein for 28 days, while a control group was inoculated with a buffer solution. The N group revealed a more significant number of spermatozoa. Spermatozoa in the seminiferous tubules were counted in twenty 400 × microscopy fields (mean of 9.2 vs. 4.6 in the control group; p &lt; 0,01), but significantly lower testosterone levels (mean of 125.70 ng/dl vs. 309,00 ng/dl in the control group; p &lt; 0,05) were found. No other histological and biochemical changes were displayed. Conclusively, these data suggest testicular hormonal imbalance mediated by the SARS-CoV-2 N protein that could be linked to reported post-COVID-19 syndrome hypogonadism. More relevant research might be performed to confirm this viral antigen’s deleterious mechanism in the human testicular microenvironment, particular in Leydig cell function.