Pathological Findings in the Testes of COVID-19 Patients: Clinical Implications

Effects of SARS-CoV-2 infection on human reproduction

The worldwide infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacts human health and life on multiple levels. People infected with SARS-CoV-2 suffer from physical disorders and psychological distress. At present, no direct evidence indicates that SARS-CoV-2 negatively influences human reproduction, and the possibility that gametes and embryos are affected requires further investigation. To evaluate the potential effects of SARS-CoV-2 infection on human reproduction and fetal health, this review summarizes the basic and clinical research of SARS-CoV-2 on reproduction up to date, hoping to offer guidance and advice to people at reproductive age and provide clues for the prevention and treatment of associated diseases.

COVID-19 Pandemic and Male Fertility: Clinical Manifestations and Pathogenic Mechanisms

The novel coronavirus disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been a major public health emergency worldwide with over 118.27-million confirmed COVID-19 cases and 2.62-million deaths recorded, as of March 12, 2021. Although this disease primarily targets lungs, damages in other organs, such as heart, kidney, liver, and testis, may occur. Testis is the cornerstone of male reproduction, while reproductive health is the most valuable resource for continuity of the human race. Given the unique nature of SARS-CoV-2, the mechanisms of its impact on the testes have yet to be fully explored. Notably, coronaviruses have been found to invade target cells through the angiotensin-converting enzyme 2 receptor, which can be found in the respiratory, gastrointestinal, cardiovascular, urinary tract, and reproductive organs, such as testes. Coronavirus studies have suggested that testes might be a potential target for SARS-CoV-2 infection. The first etiopathogenic concept proposed by current hypotheses indicates that the virus can invade testes through the angiotensin-converting enzyme 2 receptor. Next, the activated inflammatory response in the testes, disease-associated fever, and COVID-19 medications might be implicated in testicular alterations. Although evidence regarding the presence of SARS-CoV-2 mRNA in semen remains controversial, this emphasizes the need for researchers to pay closer attention to sexually transmitted diseases and male fertility after recovering from COVID-19. In this review the latest updates regarding COVID-19-associated testicular dysfunction are summarized and possible pathogenic mechanisms are discussed.

Postmortem Findings Associated With SARS-CoV-2: Systematic Review and Meta-analysis

Coronavirus Disease 2019 (COVID-19), caused by the novel Severe Acute Respiratory Syndrome-associated Coronavirus 2 (SARS-CoV-2), has become a global threat to public health. COVID-19 is more pathogenic and infectious than the prior 2002 pandemic caused by SARS-CoV-1. The pathogenesis of certain disease manifestations in COVID-19 such as diffuse alveolar damage (DAD) are thought to be similar to SARS-CoV-1. However, the exact pathogenesis of COVID-19 related deaths remains poorly understood. The aim of this article was to systematically summarize the rapidly emerging literature regarding COVID-19 autopsies. A meta-analysis was also conducted based on data accrued from preprint and published articles on COVID-19 (n=241 patients) and the results compared with postmortem findings associated with SARS-CoV-1 deaths (n=91 patients). Both autopsy groups included mostly adults of median age 70 years with COVID-19 and 50 years with SARS-CoV-1. Overall, prevalence of DAD was more common in SARS-CoV-1 (100.0%) than COVID-19 (80.9%) autopsies (P=0.001). Extrapulmonary findings among both groups were not statistically significant except for hepatic necrosis (P <0.001), splenic necrosis (P<0.006) and white pulp depletion (P <0.001) that were more common with SARS-CoV-1. Remarkable postmortem findings in association with COVID-19 apart from DAD include pulmonary hemorrhage, viral cytopathic effect within pneumocytes, thromboembolism, brain infarction, endotheliitis, acute renal tubular damage, white pulp depletion of the spleen, cardiac myocyte necrosis, megakaryocyte recruitment, and hemophagocytosis.

Is Microthrombosis the Main Pathology in Coronavirus Disease 2019 Severity?-A Systematic Review of the Postmortem Pathologic Findings

This systematic review attempts to retrieve and report the findings of postmortem studies including the histopathologic data of deceased coronavirus disease 2019 patients and to review the manifestations of coronavirus disease 2019-associated thrombotic pathologies reported in the recent literature.

DATA SOURCES

PubMed, Excerpta Medica Database, and Cochrane library between December 1, 2019, and August 26, 2020.

STUDY SELECTION

Investigators screened 360 unique references, retrieved published autopsy series, and report on the postmortem histopathologic information on patients who had died of coronavirus disease 2019.

DATA EXTRACTION

Investigators independently abstracted all available data including study design, participant demographics, key histopathologic findings, disease severity markers, duration of hospital stay, and cause of death.

DATA SYNTHESIS

From the 65 eligible studies, 691 total completed autopsies were included in evidence synthesis. Histopathologic evaluation of the lungs revealed presence of diffuse alveolar damage in 323 of 443 patients and pulmonary microthrombi in 242 of 326 patients. Deep venous thrombosis and pulmonary embolism were found in 41% and ~15%, respectively, of the cadavers examined for thromboembolic events. d-dimer levels were generally higher in patients with severe clinical course of coronavirus disease 2019. Plasma levels of ferritin, lactate dehydrogenase, interleukin-6, and C-reactive protein were higher in nonsurvivors when compared with survivors. Overall, microthrombi and extensive angiogenesis of lung vasculature were the most common pathologic findings in the lungs and microthrombi in most of the assessed organ-tissue.

CONCLUSIONS

Diffuse alveolar damage was the most predominant feature in the lungs of coronavirus disease 2019 patients who underwent postmortem assessment. Widespread pulmonary microthrombosis and extensive pulmonary angiogenesis, in addition to frequent pulmonary and extrapulmonary microthrombotic and thromboembolic findings in patients with coronavirus disease 2019, appear to be consistent with the disease-specific hypercoagulability. Further discovery efforts in assessing the link between coronavirus disease 2019, hypercoagulable state, and immunothrombosis are warranted. In the interim, increased attention to anticoagulant treatment approaches in coronavirus disease 2019 patients is needed.

Short-term effects of COVID-19 on semen parameters: A multicenter study of 69 cases

Objective

COVID‐19, which is known to be caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), is a global health problem that can cause multiorgan damage because of its use of the angiotensin‐converting enzyme 2 (ACE2) receptor in its pathophysiology. We aimed to investigate whether SARS‐CoV‐2 had a short‐term effect on spermatogenesis, which plays an important role in male reproductive health as it has abundant ACE2 expression in testicular tissue.

Material and methods

This multicenter study included 69 patients aged 20–45 years, who admitted to our hospitals between April 2020 and October 2020 with a history of a positive test result for SARS‐CoV‐2 based on the nasopharyngeal or oropharyngeal swab samples and had recovered from the disease at least three months earlier and who had undergone a spermiogram test in the hospital database within the last year before the onset of disease. The patients were divided into two groups according to their COVID‐19 symptoms being mild or moderate, depending on whether they had received home treatment or required hospitalization for oxygen therapy. Semen samples taken before and after COVID‐19 were compared within and between the groups in terms of sperm parameters.

Results

The mean age of the patients included in the study was 30.4±4.8 years in the mild symptomatic COVID‐19 group and 31.06±4.2 years in the moderate symptomatic group. When the spermiogram samples of the patients before and after COVID‐19 were evaluated, it was found that motility and vitality significantly decreased in the mild symptomatic group, while the decrease in all semen parameters was statistically significant in the moderate symptomatic group.

Conclusion

Although the mechanism by which COVID‐19 causes testicular involvement remains uncertain, its short‐term results on spermatogenesis reveals that COVID‐19 negatively affects sperm parameters.

Structural and physiological changes of the human body upon SARS-CoV-2 infection

Since December 2019, the novel coronavirus (severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) has spread to many countries around the world, developing into a global pandemic with increasing numbers of deaths reported worldwide. To data, although some vaccines have been developed, there are no ideal drugs to treat novel coronavirus pneumonia (coronavirus disease 2019 (COVID-19)). By examining the structure of the coronavirus and briefly describing its possible pathogenesis based on recent autopsy reports conducted by various teams worldwide, this review analyzes the possible structural and functional changes of the human body upon infection with SARS-CoV-2. We observed that the most prominent pathological changes in COVID-19 patients are diffuse alveolar damage (DAD) of the lungs and microthrombus formation, resulting in an imbalance of the ventilation/perfusion ratio and respiratory failure. Although direct evidence of viral infection can also be found in other organs and tissues, the viral load is relatively small. The conclusion that the injuries of the extra-pulmonary organs are directly caused by the virus needs further investigation.

The impact of SARS-CoV-2 and COVID-19 on male reproduction and men's health

Many couples initially deferred attempts at pregnancy or delayed fertility care due to concerns about coronavirus disease 2019 (COVID-19). One significant fear during the COVID-19 pandemic was the possibility of sexual transmission. Many couples have since resumed fertility care while accepting the various uncertainties associated with severe acute respiratory syndrome coronavirus 2, including the evolving knowledge related to male reproductive health. Significant research has been conducted exploring viral shedding, tropism, sexual transmission, the impact of male reproductive hormones, and possible implications to semen quality. However, to date, limited definitive evidence exists regarding many of these aspects, creating a challenging landscape for both patients and physicians to obtain and provide the best clinical care. This review provides a comprehensive assessment of the evolving literature concerning COVID-19 and male sexual and reproductive health, and guidance for patient counseling.

Bioinformatic and mouse model reveal the potential high vulnerability of Leydig cells on SARS-CoV-2

Background

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in China and spread rapidly since the end of 2019. Previous studies have confirmed that SARS-CoV-2 infects host cells via binding to angiotensin converting enzyme II (ACE2).

Methods

To explore the expression of ACE2 and the potential risk of infection in testis, we performed a bioinformatic analysis based on public databases, and conducted a pilot study using a mouse model. We also collected clinical follow-up date on male patients who had recovered from COVID-19 for 6 months.

Results

The results showed that the RNA expression of ACE2 was higher in testis compared with other organs. Single-cell analysis and immunocytochemistry further indicated that Leydig cells were at risk of SARS-CoV-2 infection. Green fluorescence was only detected in the Leydig cells after intratesticular injection of pseudovirus SARS-CoV-2 in the mouse model. In the clinical follow-up, serum total testosterone level was statistically lower in patients who had recovered from COVID-19 compared with healthy men (P=0.010).

Conclusions

The findings of the present study indicate the potential vulnerability of Leydig cells. It is important to monitor the reproductive system and its complications in male COVID-19 patients. Further studies are still needed on SARS-CoV-2-associated reproductive complications.

Effect of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) on reproductive system

Since the emergence of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in December 2019, it has rapidly spread across many countries and it has become a crucial global health concern. Furthermore, SARS-CoV-2 infection not only effect on respiratory system, but on reproductive system of human. However, there has been not any review described the transmission paths and effects of SARS-CoV-2 infection on human reproductive system, systematically. In order to describe the transmission paths of SARS-CoV-2, effect on the male/female reproductive system of SARS-CoV-2 and some successful prevention measures. We would like to review effect of SARS-CoV-2 on reproductive system. To conclude, SARS-CoV-2 infection might damage to male reproductive system via ACE2 receptor mediating and male patients were reportedly slightly more affected than women by SARS-CoV-2 infections.

Pathological Findings in COVID-19 as a Tool to Define SARS-CoV-2 Pathogenesis. A Systematic Review

Introduction: The World Health Organization declared the COVID-19 pandemic in March 2020. COVID-19 still represents a worldwide health emergency, which causesa severe disease that has led to the death of many patients. The pathophysiological mechanism of SARS-CoV-2 determining the tissue damage is not clear and autopsycan be auseful tool to improve the knowledge of this infection and, thus, it can help achieve a timely diagnosis and develop an appropriate therapy. This is an overview of the main post-mortem findings reporting data on the infection effects on several organs. Methods: A systematic literature search was conducted in the PubMed database searching for articles from 1 January to August 31, 2020. Thearticles were selected identifying words/concepts in the titles and/or abstracts that indicated the analysis of the morphological/pathological tissue injuries related to SARS-CoV-2 disease by several investigations. Results: A total of 63 articles were selected. The main investigated tissue was the lung showing a diffuse alveolar damage (DAD) frequently associated with pulmonary thrombotic microangiopathy. Inflammatory findings and vascular damage were observed in other organs such as heart, liver, kidney, brain, spleen, skin and adrenal gland. The immunohistochemical analysis showed tissue inflammatory cells infiltrates. The virus presence was detected by several investigations such as RT-PCR, immunohistochemistry and electron microscope, showing the effect ofSARS-CoV-2not exclusively in the lung. Discussion: The evidence emerging from this review highlighted the importance of autopsy to provide a fundamental base in the process of understanding the consequences ofSARS-CoV-2 infection. COVID-19 is strictly related to a hyper inflammatory state that seems to start with DAD and immuno-thrombotic microangiopathy. Massive activation of the immune system and microvascular damage might also be responsible for indirect damage to other organs, even if the direct effect of the virus on these tissues cannot be excluded.

Biorepositories (biobanks) of human body fluids and materials as archives for tracing early infections of COVID-19

Identifying the individuals and geographical regions witnessing early infections or outbreaks of SARS-CoV-2 and its variants is helpful for studying the early epidemiology or even the origin of the novel coronavirus. Here, we put forward a strategy that can potentially contribute to this goal. Human body fluids and biological materials collected before the COVID-19 pandemic may serve as archives for retrospective testing of early human infections before the recent outbreaks. These have been routinely donated, collected, and archived, creating biorepositories or "biobanks" for clinical or research purposes. SARS-CoV-2 genetic materials and its antibodies have been confirmed in various types of biological samples from COVID-19 patients, including blood, sperm, umbilical cord blood, lung, heart, kidney and so on, making these biological archives as candidates for detecting early COVID-19 infections. Unlike sewage-based epidemiology which only provides information on the geographical aspect, viruses identified in archived human biological samples provide direct links to individuals, from whom a wealth of personal information including their profession, hobbies and activities, travel history, and previous exposure to wildlife can all be retrieved. By analyzing the patterns and links in the behavior of those early infected individuals, it is possible to trace the origin of the virus, for instance, in certain wild animals or local environments.

"Mask up to keep it up": Preliminary evidence of the association between erectile dysfunction and COVID-19

Background

Erectile dysfunction (ED), as the hallmark of endothelial dysfunction, could be a short‐ or long‐term complication of COVID‐19. Additionally, being ED a clinical marker and predictor of non‐communicable chronic diseases, particularly cardiovascular, subjects with ED could potentially have a higher risk of contracting COVID‐19.

Objectives

To investigate the prevalence of ED among subjects with a reported diagnosis of COVID‐19 and to measure the association of COVID‐19 and ED.

Materials and methods

We reviewed data from the Sex@COVID online survey (performed between April 7 and May 4, 2020, in Italy) to retrieve a sample of Italian male sexually active subjects with reported SARS‐CoV‐2 infection. A matching sample of COVID‐19‐negative male sexually active subjects was also retrieved using propensity score matching in a 3:1 ratio. The survey used different standardized psychometric tools to measure effects of lockdown and social distancing on the intrapsychic, relational, and sexual health of Italian subjects.

Results

One hundred subjects were included in the analysis (25 COVID‐positive; 75 COVID‐negative). The prevalence of ED, measured with the Sexual Health Inventory for Men, was significantly higher in the COVID+ group (28% vs. 9.33%; p = 0.027). Logistic regression models confirmed a significant effect of COVID‐19 on the development of ED, independently of other variables affecting erectile function, such as psychological status, age, and BMI [OR 5.66, 95% CI: 1.50–24.01]. Likewise, subjects with ED were more likely to have COVID‐19, once corrected for age and BMI [OR 5.27, 95% CI: 1.49–20.09].

Discussion and conclusion

On top of well‐described pathophysiological mechanisms, there is preliminary evidence in a real‐life population of ED as a risk factor of developing COVID‐19 and possibly occurring as a consequence of COVID‐19. Universal vaccination against the COVID‐19 and the personal protective equipment could possibly have the added benefit of preventing sexual dysfunctions.

COVID-19 and human reproduction: A pandemic that packs a serious punch

The COVID-19 pandemic has led to a worldwide health emergency that has impacted 188 countries at last count. The rapid community transmission and relatively high mortality rates with COVID-19 in modern times are relatively unique features of this flu pandemic and have resulted in an unparalleled global health crisis. SARS-CoV-2, being a respiratory virus, mainly affects the lungs, but is capable of infecting other vital organs, such as brain, heart and kidney. Emerging evidence suggests that the virus also targets male and female reproductive organs that express its main receptor ACE2, although it is as yet unclear if this has any implications for human fertility. Furthermore, professional bodies have recommended discontinuing fertility services during the pandemic such that reproductive services have also been affected. Although increased safety measures have helped to mitigate the propagation of COVID-19 in a number of countries, it seems that there is no predictable timeline to containment of the virus, a goal likely to remain elusive until an effective vaccine becomes available  and widely distributed across the globe. In parallel, research on reproduction has been postponed for obvious reasons, while diagnostic tests that detect the virus or antibodies against it are of vital importance to support public health policies, such as social distancing and our obligation to wear masks in public spaces. This review aims to provide an overview of critical research and ethics issues that have been continuously emerging in the field of reproductive medicine as the COVID-19 pandemic tragically unfolds.Abbreviations: ACE2: angiotensin- converting enzyme 2; ART: Assisted reproductive technology; ASRM: American Society for Reproductive Medicine; CCR9: C-C Motif Chemokine Receptor 9; CDC: Centers for Disease Control and Prevention; COVID-19: Coronavirus disease 2019; Ct: Cycle threshold; CXCR6: C-X-C Motif Chemokine Receptor 6; ELISA: enzyme-linked immunosorbent assay; ESHRE: European Society of Human Reproduction and Embryology; ET: Embryo transfer; FSH: Follicle Stimulating Hormone; FFPE: formalin fixed paraffin embedded; FYCO1: FYVE And Coiled-Coil Domain Autophagy Adaptor 1; IFFS: International Federation of Fertility Societies; IUI: Intrauterine insemination; IVF: In vitro fertilization; LH: Luteinizing Hormone; LZTFL1: Leucine Zipper Transcription Factor Like 1; MAR: medically assisted reproduction services; MERS: Middle East Respiratory syndrome; NGS: Next Generation Sequencing; ORF: Open Reading Frame; PPE: personal protective equipment; RE: RNA Element; REDa: RNA Element Discovery algorithm; RT-PCR: Reverse=trascriptase transcriptase-polymerase chain reaction; SARS: Severe acute respiratory syndrome; SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus 2; SLC6A20: Solute Carrier Family 6 Member 20; SMS: Single Molecule Sequencing; T: Testosterone; TMPRSS2: transmembrane serine protease 2; WHO: World Health Organization; XCR1: X-C Motif Chemokine Receptor.

Autopsy Tool in Unknown Diseases: The Experience with Coronaviruses (SARS-CoV, MERS-CoV, SARS-CoV-2)

In the last two decades, three unknown pathogens have caused outbreaks, generating severe global health concerns. In 2003, after nucleic acid genotyping, a new virus was named severe acute respiratory syndrome coronavirus (SARS-CoV). After nine years, another coronavirus emerged in the middle east and was named MERS-CoV (Middle East Respiratory Syndrome-Coronavirus). Finally, in December 2019, a new unknown coronavirus was isolated from a cluster of patients and was named SARS-CoV-2 (COVID-19, coronavirus disease 2019). This review aims to propose a complete overview of autopsy in the three coronaviruses over the past two decades, showing its pivotal role in the management of unknown diseases. A total of 116 studies fulfilled the inclusion criteria: 14 studies were collected concerning SARS-CoV (87 autopsy reports, from Asian and American countries), 2 studies for MERS-CoV (2 autopsy reports, from Middle-East Asian countries), and 100 studies on SARS-CoV-2 (930 autopsy reports). Analyzing the data obtained on COVID-19, based on the country criterion, a large number of post-mortem investigation were performed in European countries (580 reports), followed by American countries (251 reports). It is interesting to note that no data were found from the Oceanic countries, maybe because of the minor involvement of the outbreak. In all cases, autopsy provided much information about each unknown coronavirus. Despite advanced technologies in the diagnostic fields, to date, autopsy remains the gold standard method to understand the biological features and the pathogenesis of unknown infections, especially when awareness of a pathogen is restricted and the impact on the healthcare system is substantial. The knowledge gained through this technique may positively influence therapeutic strategies, ultimately reducing mortality.

COVID-19 and male fertility: Taking stock of one year after the outbreak began

Objectives: The aim of this review is to summarize, following a timeline, the current knowledge regarding the effects of the Sars-cov2 virus on male fertility, researching the pathological and clinical results of the studies published in the last year. Methods: A systematic research was performed on the major international online databases; Thirty-five articles were selected. Results: A statistically significant reduction in testosterone levels and sperm quality in subjects with COVID-19 has been highlighted in several papers; however, in many cases the tests have been conducted in patients with active disease and long-term consequences are still not known. Some studies have confirmed the presence of the virus in the testis in a low percentage of patients; viral presence in sperm has only been found in one study. Testicular discomfort, which could indicate viral orchitis, was highlighted in several works, with an incidence of up to 19% percent of patients. The presence of inflammatory lymphocytic infiltrates, IgG and inflammatory cytokines have been documented in several works; pathological signs of inflammation were found in 60.9% of testicular biopsies performed in one study. The entry of the virus into the testis cells, both stromal and seminal cells appeared to be Angiotensin Converting Enzyme-2 (ACE2) mediated, as it also occurs in other tissues. DNA fragmentation, reactive oxygen species (ROS) formation, autoantibody production and ACE2 mediated effect have all been hypothesized as cause of cellular damage. Conclusions: The results on effects of COVID-19 infection on the male reproductive system are currently insufficient as they are based on a small number of patients and therefore are often contradictory.Certain mechanisms of testicular damage are still to be assessed, as any risk categories like age, ethnicity, or others. As for the transmission of the virus through sperm, there is insufficient evidence to ensure that this cannot happen.

Effects of COVID-19 on male sex function and its potential sexual transmission

INTRODUCTION

Severe Acute Respiratory Syndrome Coronavirus 2, (SARS-CoV-2) was first identified by the Chinese Centers for Disease Control and Prevention on January 8, 2020 and was declared as a global pandemic on March 11, 2020 by WHO. SARS-CoV-2 uses the Angiotensin-converting enzyme 2 (ACE2) receptor as an entry route, associated with the transmembrane serine protease protein (TMPRSS2), which makes the testis and particularly spermatogenesis potentially vulnerable, since this tissue has high expression of ACE2.

MATERIAL AND METHODS

We performed a systematic literature review by electronic bibliographic databases in Pubmed, Scopus and ScienceDirect up to August 2020 about the effect of SARS-CoV-2 on male sexual function and its transmission, to assess possible repercussions on sex organs and the existence of a sexual transmission path.

RESULTS

Although SARS-CoV-2 presence has not been found in testicle samples, it has been demonstrated that it causes histological changes compatible with orchitis, and sex hormone disturbances. TMPRSS2 is up-regulated in prostate cancer where it supports tumor progression, thus these patients may have a higher risk of SARS-CoV-2 infection. TMPRSS2 inhibitors may be useful for the treatment or prevention of COVID-19. No viral material has been found in blood or semen, however it has been proven to be present in stool and saliva.

CONCLUSION

The male reproductive system would be highly vulnerable and susceptible to infection by SARS-CoV-2 given the expression of the ACE2 receptor in somatic and germ cells. The seminal fluid would remain free of viral presence in patients with COVID-19. Regardless, non-genital sex could be an important source of viral transmission. In assisted reproduction techniques all necessary tests must be carried out to ensure the donor is free of the virus at the time of collection and handling of the seminal sample.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): a Systemic Infection

To date, seven identified coronaviruses (CoVs) have been found to infect humans; of these, three highly pathogenic variants have emerged in the 21st century. The newest member of this group, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected at the end of 2019 in Hubei province, China. Since then, this novel coronavirus has spread worldwide, causing a pandemic; the respiratory disease caused by the virus is called coronavirus disease 2019 (COVID-19). The clinical presentation ranges from asymptomatic to mild respiratory tract infections and influenza-like illness to severe disease with accompanying lung injury, multiorgan failure, and death. Although the lungs are believed to be the site at which SARS-CoV-2 replicates, infected patients often report other symptoms, suggesting the involvement of the gastrointestinal tract, heart, cardiovascular system, kidneys, and other organs; therefore, the following question arises: is COVID-19 a respiratory or systemic disease? This review aims to summarize existing data on the replication of SARS-CoV-2 in different tissues in both patients and ex vivo models.

Severely low testosterone in males with COVID-19: A case-control study

Background

Circulating androgens could have a relevant pathobiological role in clinical outcomes in men with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection (COVID‐19).

Objectives

We aimed to assess: (a) circulating sex steroids levels in a cohort of 286 symptomatic men with laboratory‐confirmed COVID‐19 at hospital admission compared to a cohort of 281 healthy men; and (b) the association between serum testosterone levels (tT), COVID‐19, and clinical outcomes.

Materials and Methods

Demographic, clinical, and hormonal values were collected for all patients. Hypogonadism was defined as tT ≤9.2 nmol/l. The Charlson Comorbidity Index (CCI) was used to score health‐significant comorbidities. Severe clinical outcomes were defined as patients either transferred to intensive care unit (ICU) or death. Descriptive statistics and multivariable linear and logistic regression models tested the association between clinical and laboratory variables and tT levels. Univariable and multivariable logistic regression models tested the association between tT and severe clinical outcomes.

Results

Overall, a significantly lower levels of LH and tT were found in patients with COVID‐19 compared to healthy controls (all p < 0.0001); conversely, healthy controls depicted lower values of circulating E₂ (p < 0.001). Testosterone levels suggestive for hypogonadism were observed in 257 (89.8%) patients at hospital admission. In as many as 243 (85%) cases, hypogonadism was secondary. SARS‐CoV‐2 infection status was independently associated with lower tT levels (p < 0.0001) and greater risk of hypogonadism (p < 0.0001), after accounting for age, BMI, CCI, and IL‐6 values. Lower tT levels were associated with higher risk of ICU admission and death outcomes (all p ≤ 0.05), after accounting for clinical and laboratory parameters.

Conclusions

We unveil an independent association between SARS‐CoV‐2 infection status and secondary hypogonadism already at hospital admission, with lower testosterone levels predicting the most severe clinical outcomes.

Does SARS-CoV-2 Threaten Male Fertility?

In the continuing COVID-19 pandemic, one of the most important concerns in reproductive health is the issue of male fertility of recovered patients. In this study, we discuss the potential mechanisms that justify the possible impact of COVID-19 on male fertility. The main point of entry of SARS-CoV-2 into the host cells appears to be through the viral spike protein which permits entry into cells via the angiotensin-converting enzyme 2 (ACE2 receptor). In human testes, ACE2 is enriched in Sertoli and Leydig cells and spermatogonia. Also, it seems that there is a mild or severe cytokine storm in patients with severe COVID-19, and such changes may affect fertility. It should also be mentioned that the orchitis caused by the SARS-CoV-2 virus may have an important impact on fertility. Prolonged and high fever may lead to changes in testicular temperature and destroy germ cells. In general, there is little evidence for a definite conclusion, but there are facts that suggest that COVID-19 may affect male fertility. It is prudent for men of reproductive age who have recovered from COVID-19 to be evaluated for the presence of the virus in semen and fertility-related items. There is an urgent need to conduct quality studies on, in particular, the long-term effects of COVID-19 on the fertility of recovered males.

Potential impacts of COVID-19 on reproductive health: Scientific findings and social dimension

COVID-19 virus is classified as a respiratory disease that can be mainly transmitted via respiratory droplets, however, there are recently published reports suggested its ability to transmit via sexual intercourse, assisted reproductive technology (ART) treatments, pregnancy, and nursing. Although SARS-CoV-2 mainly attacks respiratory systems, manifestations of multiple organs have been detected. A significant concern was raised about whether COVID-19 may affect female and male reproductive functions. These findings imposed more restrictions on social relationships between individuals even if inside the family, adding more physiologic load. In this context, there is a crucial need to identify the biological and behavioral reproductive risk factors associated with COVID-19 disease. Questions regarding the potential risks of sexual transmission during intercourse and/or application of ART, vertical transmission (throughout pregnancy, delivery, and breastfeeding), the health of pregnant and postpartum women, and fetal or postnatal health problems of neonates/children remain largely unanswered. The contribution of individuals to different social and economic activities depends on the maintenance of good quality life and health. The ongoing COVID-19 pandemic raised on the end of December 2019 has drastically affected different aspects of human wellbeing. The pandemic not only affected the health of individuals, but also negatively affected mental health and social interaction. This review illustrates: a) scientific findings related to the impact of the COVID-19 pandemic on the reproductive process, considering gender, hormonal balance, gonad functions, pregnancy, and ART, b) the sociosexual dimension of COVID-19 disease and precautions that should be taken to avoid infection via sexual transmission or vertical transmission, which may alleviate the fear associated with continuing normal social relationships and economic activities.

The other side of COVID-19 pandemic: Effects on male fertility

The outbreak of novel coronavirus disease 2019 (COVID-19) has become a major pandemic threat worldwide. According to the existing clinical data, this virus not only causes respiratory diseases and affects the lungs but also induces histopathological or functional changes in various organs like the testis and also the male genital tract. The renin-angiotensin system (RAS), also ACE 2 and TMPRSS2 play an important role in the cellular entry for SARS-CoV-2. Because the male genital system presents high ACE 2 expression, the importance of this pathway increases in COVID-19 cases. As the COVID-19 pandemic has affected the male genital system in direct or indirect ways and showed a negative impact on male reproduction, this paper focuses on the possible mechanisms underlying the damage caused by COVID-19 to the testis and also other components of the male genital tract.

Covid19, beyond just the lungs: A review of multisystemic involvement by Covid19

With the commencement of the COVID19 pandemic, following its 1st case reported in Wuhan in China, the knowledge about the virus as well as the symptoms produced by the disease have drastically increased to this day. The manifestations of COVID19 is now known to affect multiple organ systems of the body, which have shown to have acute as well as chronic complications. Histopathological analysis of the biopsies from the affected organs have implied a direct cytopathic effect of the virus but at the same time not ruling out other causes like hypoxia metabolic changes etc., occurring during the course of the disease. In this review article, we have highlighted the histopathological changes in various organs as reported by various studies throughout the world for a better understanding of the etiopathogenesis of COVID19.

Being pregnant in the COVID-19 pandemic: Effects on the placenta in all aspects

The coronavirus disease 2019 (COVID‐19), which had spread to the world from Wuhan (China) in late December, was announced as a pandemic by the World Health Organization in March 2020. In addition to acute respiratory syndrome symptoms, this virus also affects nonrespiratory organs, according to existing data. ACE2 and TMPRSS2, which play a critical role in the entrance of SARS‐COV‐2 into the cell, are coexpressed in placental development stages, so the placenta also carries a risk for this virus. Many studies have shown that this virus causes some histopathological changes in the placenta. The vertical transmission of the virus is not yet clear, but available data have shown that the indirect effects of the virus can be seen on the fetus. This article focuses on revealing the effects of the virus on the placenta in all aspects.

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The placenta also shows antiviral activity due to placental growth factors, cytokines, and chemokines, so the use of placental extracts as therapeutic agents in the treatment of COVID‐19 needs authority regulations and clinical guidelines.

Anti-infection mechanism of phosphodiesterase-5 inhibitors and their roles in coronavirus disease 2019 (Review)

Coronavirus disease 2019 (COVID-19) has a variety of impacts on the human body. Severe acute respiratory syndrome coronavirus 2 is the pathogen that causes COVID-19. It invades human tissues through the receptor angiotensin-converting enzyme 2, resulting in an imbalance in the angiotensin II (AngII) level and upregulation of renin-angiotensin system/AngII pathway activity. Furthermore, the binding of AngII to its receptor leads to vasoconstriction, endothelial injury and intravascular thrombosis. In addition, COVID-19 may have adverse effects on male reproductive organs and a marked impact on male reproductive health. Phosphodiesterase-5 inhibitors (PDE5Is) may improve vascular endothelial function, promote testicular and systemic blood circulation and testosterone secretion and enhance epididymal function, as well as sperm maturation and capacitation. PDE5Is may also be of use in the treatment of infectious diseases by enhancing immunity and anti-inflammatory responses and improving vascular endothelial function. Based on the pharmacological mechanism of PDE5Is, they are of unique value in the fight against infectious diseases and may be effective in combination with direct antiviral drugs. The anti-infection mechanisms of PDE5Is and their roles in COVID-19 were reviewed in the present study.

COVID-19 may affect male fertility but is not sexually transmitted: a systematic review

Objective

To determine if SARS-CoV-2, which has led to the rapidly spreading COVID-19 global pandemic, is sexually transmitted. Since the putative receptor for the virus is identified in reproductive organs, it is also important to examine if COVID-19 may affect human fertility.

Evidence Review

A systematic review of English publications was conducted up to December 11, 2020 in PubMed, NIH iCite COVID-19 portfolio, Cochrane Library, and Google Scholar databases, searching for SARS-CoV-2 in the testes; seminal, prostatic, and vaginal fluids; and cervical smears. A total of 1,997 records were identified, duplicates were removed, and 1,490 records were reviewed for eligibility by examining titles and abstracts. Subsequently, 202 full-text relevant articles were reviewed by 2 independent reviewers. Forty-seven studies (literature reviews, editorials, and guidelines) were assessed qualitatively, and 23 studies that tested the male and female reproductive tracts of patients with COVID-19 for SARS-CoV-2 were quantitatively analyzed.

Results

No epidemiological investigations to date have described evidence suggesting that COVID-19 is an STD. While angiotensin-converting enzyme 2 receptor is found in the reproductive organs, the lack of co-expression of the TMPRSS2 modulatory protein, required for SARS-CoV-2 cell entry, in testicular cells, sperm, or oocytes, argues against the hypothesis that gametes transmit SARS-CoV-2. Molecular detection studies of SARS-CoV-2 RNA in the male and female reproductive tracts were summarized: 98.0% (293/299) of the seminal fluids, 16/17 testicular biopsies, all 89 prostatic fluids, 98.3% (57/58) of the vaginal fluids, all 35 cervical smears, and all 16 oocyte samples tested negative for SARS-CoV-2. None of the studies confirmed sexual transmission of SARS-CoV-2. Nonetheless, COVID-19 may have detrimental effects on male reproduction by inducing orchitis and/or decreasing testosterone levels, sperm counts, and motility.

Conclusion

On the basis of the current worldwide published information, COVID-19 is not an STD. This information is important for clinicians, proposed guidelines for public health, U.S. Food and Drug Administration guidelines for gamete and tissue donor eligibility, and fertility treatments. Universal precautions, currently practiced worldwide, are adequate and sufficient at this time to prevent the transmission of known or unknown viral infections. We suggest that recovered patients of COVID-19, especially those with infertility, should be evaluated for their ovarian and testicular function.

COVID-19 and male reproduction: Current research and unknown factors

BACKGROUND

The testes are suspected target organs of SARS-CoV-2. However, the results of studies on the effect of COVID-19 on male reproduction are controversial.

OBJECTIVE

To summarize current research on the effects of COVID-19 on male reproduction.

METHODS

A systematic review of English literature was performed using PubMed and Ovid Embase up to 18 August 2020. Research articles on the presence of SARS-CoV-2 in semen, the effects of the virus on semen parameters and any pathological changes in the testes were evaluated.

RESULTS

Fourteen studies were included in this review. Six of 176 survivors (3.4%) and 1 of 13 decedents (7.7%) in 2 of 12 studies were positive for viral RNA in semen and testicular tissue, respectively. After stratification of patient groups, we found that the virus was detected in the relatively early stage of infection, 6-16 days after disease onset, in semen from survivors. Two of 3 studies reported that some participants had substandard semen quality after COVID-19, and 1 study found that COVID-19 may impair semen quality in a severity-related manner. Pathological analyses showed that injuries to the seminiferous tubule occurred in all decedents (N = 11). Another study found that orchitic and testis fibrin microthrombi occurred in patients with fatal disease (100%, N = 2). Scrotal discomfort of orchiepididymitis or spermatic cord inflammation has also been reported in COVID-19 patients.

CONCLUSION

Current studies suggest that semen is rarely considered a carrier of SARS-CoV-2 genetic material during the infection period but not in the semen of recovered patients. Fatal COVID-19 may cause testicular structure damage without the presence of virus.

COVID-19 in the paediatric population of Kazakhstan

Background: To date, there have been no studies of COVID-19 infection in children in Central Asia, particularly the Republic of Kazakhstan. This report analyses the epidemiological data on COVID-19 infection in children in Kazakhstan.Methods: The study included 650 paediatric patients diagnosed with COVID-19. Demographic and epidemiological data and the symptoms and radiological evidence of complications were collected and analysed. Children were sub-divided into four groups: neonates/infants, young children, older children and adolescents.Results: All of the 650 children were under 19 years of age, 56.3% of whom were male, and 122 (18.8%) were newborns and infants. The majority of cases (n = 558, 85.8%) were asymptomatic and only four cases were severe (0.6%). The symptoms were as follows in descending order: cough (14.8%), sore throat (12.8%), fever (9.1%) and rhinorrhoea (5.5%). Diarrhoea (2%), dyspnoea (1.8%) and muscle pain were rare (1.1%). Only three children required intensive care, including invasive ventilation. One patient had acute respiratory distress syndrome. There were no deaths.Conclusion: Most cases of COVID-19 infection in children in Kazakhstan were asymptomatic or the symptoms were mild. Only three patients required intensive care.

Addressing male sexual and reproductive health in the wake of COVID-19 outbreak

PURPOSE

The COVID-19 pandemic, caused by the SARS-CoV-2, represents an unprecedented challenge for healthcare. COVID-19 features a state of hyperinflammation resulting in a "cytokine storm", which leads to severe complications, such as the development of micro-thrombosis and disseminated intravascular coagulation (DIC). Despite isolation measures, the number of affected patients is growing daily: as of June 12th, over 7.5 million cases have been confirmed worldwide, with more than 420,000 global deaths. Over 3.5 million patients have recovered from COVID-19; although this number is increasing by the day, great attention should be directed towards the possible long-term outcomes of the disease. Despite being a trivial matter for patients in intensive care units (ICUs), erectile dysfunction (ED) is a likely consequence of COVID-19 for survivors, and considering the high transmissibility of the infection and the higher contagion rates among elderly men, a worrying phenomenon for a large part of affected patients.

METHODS

A literature research on the possible mechanisms involved in the development of ED in COVID-19 survivors was performed.

RESULTS

Endothelial dysfunction, subclinical hypogonadism, psychological distress and impaired pulmonary hemodynamics all contribute to the potential onset of ED. Additionally, COVID-19 might exacerbate cardiovascular conditions; therefore, further increasing the risk of ED. Testicular function in COVID-19 patients requires careful investigation for the unclear association with testosterone deficiency and the possible consequences for reproductive health. Treatment with phosphodiesterase-5 (PDE5) inhibitors might be beneficial for both COVID-19 and ED.

CONCLUSION

COVID-19 survivors might develop sexual and reproductive health issues. Andrological assessment and tailored treatments should be considered in the follow-up.

Viral pathogenesis of SARS-CoV-2 infection and male reproductive health

Coronavirus disease 2019 (COVID-19) has emerged as a new public health crisis, threatening almost all aspects of human life. Originating in bats, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted to humans through unknown intermediate hosts, where it is primarily known to cause pneumonia-like complications in the respiratory system. Organ-to-organ transmission has not been ruled out, thereby raising the possibility of the impact of SARS-CoV-2 infection on multiple organ systems. The male reproductive system has been hypothesized to be a potential target of SARS-CoV-2 infection, which is supported by some preliminary evidence. This may pose a global threat to male fertility potential, as men are more prone to SARS-CoV-2 infection than women, especially those of reproductive age. Preliminary reports have also indicated the possibility of sexual transmission of SARS-CoV-2. It may cause severe complications in infected couples. This review focuses on the pathophysiology of potential SARS-CoV-2 infection in the reproductive organs of males along with their invasion mechanisms. The risks of COVID-19 on male fertility as well as the differences in vulnerability to SARS-CoV-2 infection compared with females have also been highlighted.

The Immunopathological and Histological Landscape of COVID-19-Mediated Lung Injury

A complete understanding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) physiopathology and related histopathologic lesions is necessary to improve treatment and outcome of coronavirus disease 2019 (COVID-19) patients. Many studies have focused on autopsy findings in COVID-19-related deaths to try and define any possible specific pattern. Histopathologic alterations are principally found within lungs and blood vessels, and these abnormalities also seem to have the highest clinical impact. Nevertheless, many of the morphological data collected so far are non-specific, fickle, and possibly associated with other co-existing factors. The aim of this minireview is to describe the main histopathological features related to COVID-19 and the mechanism known as "cytokine storm".

Multi-organ proteomic landscape of COVID-19 autopsies

The molecular pathology of multi-organ injuries in COVID-19 patients remains unclear, preventing effective therapeutics development. Here, we report a proteomic analysis of 144 autopsy samples from seven organs in 19 COVID-19 patients. We quantified 11,394 proteins in these samples, in which 5,336 were perturbed in the COVID-19 patients compared to controls. Our data showed that cathepsin L1, rather than ACE2, was significantly upregulated in the lung from the COVID-19 patients. Systemic hyperinflammation and dysregulation of glucose and fatty acid metabolism were detected in multiple organs. We also observed dysregulation of key factors involved in hypoxia, angiogenesis, blood coagulation, and fibrosis in multiple organs from the COVID-19 patients. Evidence for testicular injuries includes reduced Leydig cells, suppressed cholesterol biosynthesis, and sperm mobility. In summary, this study depicts a multi-organ proteomic landscape of COVID-19 autopsies that furthers our understanding of the biological basis of COVID-19 pathology.

Testicular Atrophy and Hypothalamic Pathology in COVID-19: Possibility of the Incidence of Male Infertility and HPG Axis Abnormalities

Coronavirus disease 2019 (COVID-19), which resulted from the pandemic outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causes a massive inflammatory cytokine storm leading to multi-organ damage including that of the brain and testes. While the lungs, heart, and brain are identified as the main targets of SARS-CoV-2-mediated pathogenesis, reports on its testicular infections have been a subject of debate. The brain and testes are physiologically synchronized by the action of gonadotropins and sex steroid hormones. Though the evidence for the presence of the viral particles in the testicular biopsies and semen samples from COVID-19 patients are highly limited, the occurrence of testicular pathology due to abrupt inflammatory responses and hyperthermia has incresingly been evident. The reduced level of testosterone production in COVID-19 is associated with altered secretion of gonadotropins. Moreover, hypothalamic pathology which results from SARS-CoV-2 infection of the brain is also evident in COVID-19 cases. This article revisits and supports the key reports on testicular abnormalities and pathological signatures in the hypothalamus of COVID-19 patients and emphasizes that testicular pathology resulting from inflammation and oxidative stress might lead to infertility in a significant portion of COVID-19 survivors. Further investigations are required to monitor the reproductive health parameters and HPG axis abnormalities related to secondary pathological complications in COVID-19 patients and survivors.

SARS-CoV-2 and the reproductive system: known and the unknown..!!

Background

COVID-19 is the most recent zoonotic outbreak of coronaviruses. Mostly, it invades the cells of the respiratory system by binding to the receptor angiotensin-converting enzyme 2 (ACE2) which is also present in other organs like the kidney, testis, ovaries, breast, heart, and intestine, rendering them prone to be infected. The reproductive potential is a must for the sustenance of any species and it is our prime duty to safeguard the reproductive system of the present generation from such a deadly virus. The previously reported coronaviruses like severe acute respiratory syndrome coronavirus (SARS-CoV) had a detrimental impact on reproductive organs. There is a dearth of sufficient research to provide substantial evidence for the harmful effects of this novel virus on the reproductive system. Hence, our review compiles the knowledge available until now to boost research in this regard and to take the necessary steps in time.

Main body of abstract

Here we tried to compile all the data available on the effect of SARS-CoV-2 on the reproductive system as well as vertical transmission of the virus. All related articles published from February to August 2020 were reviewed and thoroughly analyzed. SARS-CoV-2 has been found to affect the sperm concentration and motility, thus degrading the fertility of males. In females, it is suspected that this virus affects the oocyte quality and ovarian function, resulting in infertility or miscarriage. Traces of SARS-CoV-2 virus have also been found in the breast milk of the infected mothers and the semen of infected males. Vertical transmission of SARS-CoV-2 has also been reported in some cases.

Conclusion

Based on the literature review, SARS-CoV-2 seems to have the potential of affecting both male and female reproductive tracts. This review brings together the findings and observations made in the area of reproductive health during the current pandemic. The reproductive system of the young population is preordained for subsequent disorders, infertility, reduced sperm count, and motility. Therefore, the research and medical practices should focus on possible vulnerability being posed by SARS-CoV-2 to the gametes and future generations. We, hereby, recommend close monitoring of young and pregnant COVID-19 patients concerning reproductive health with utmost priority.

The Double Edge Sword of Testosterone's Role in the COVID-19 Pandemic

COVID-19 is a complex disease with a multifaceted set of disturbances involving several mechanisms of health and disease in the human body. Sex hormones, estrogen, and testosterone, seem to play a major role in its pathogenesis, development, spread, severity, and mortalities. Examination of factors such as age, gender, ethnic background, genetic prevalence, and existing co-morbidities, may disclose the mechanisms underlying SARS-CoV-2 infection, morbidity, and mortality, paving the way for COVID-19 amelioration and substantial flattening of the infection curve. In this mini-review, we focus on the role of testosterone through a discussion of the intricate mechanisms of disease development and deterioration. Accumulated evidence suggests that there are links between high level (normal male level) as well as low level (age-related hypogonadism) testosterone in disease progression and expansion, supporting its role as a double-edged sword. Unresolved questions point to the essential need for further targeted studies to substantiate these contrasting mechanisms.

Histopathology and Ultrastructural Findings of Fatal COVID-19 Infections on Testis

PURPOSE

To evaluate the presence and analyze the pathological changes within the testes of patients who died or recovered from severe acute respiratory syndrome coronavirus 2 (COVID-19) complications.

MATERIALS AND METHODS

Testis tissue was collected from autopsies of COVID-19 positive (n=6) and negative men (n=3). Formalin-fixed paraffin-embedded tissues were stained with hematoxylin and eosin (H&E) and subjected to immunofluorescence for angiotensin-converting enzyme 2 (ACE-2) expression. Fluorescent-labeled tissue slides were imaged on a quantitative pathology scope with various zoom levels allowing for qualitative and quantitative interpretation. Tissue from four COVID-19 positive autopsy cases and a live seroconverted patient was imaged with transmission electron microscopy (TEM).

RESULTS

H&E histomorphology showed three of the six COVID-19 biopsies had normal spermatogenesis while the remaining three had impaired spermatogenesis. TEM showed the COVID-19 virus in testis tissue of one COVID-19 positive autopsy case and the live biopsy, H&E stain on the same autopsy case demonstrated interstitial macrophage and leukocyte infiltration. Immunofluorescent stained slides from six COVID-19 positive men demonstrated a direct association between increased quantitative ACE-2 levels and impairment of spermatogenesis.

CONCLUSIONS

The novel COVID-19 has an affinity for ACE-2 receptors. Since ACE-2 receptor expression is high in the testes, we hypothesized that COVID-19 is prevalent in testes tissue of infected patients. This study suggests the male reproductive tract, specifically the testes, may be targets of COVID-19 infection. We found an inverse association between ACE-2 receptor levels and spermatogenesis, suggesting a possible mechanism of how COVID-19 can cause infertility.

Testosterone target therapy: focus on immune response, controversies and clinical implications in patients with COVID-19 infection

The pandemic acute respiratory syndrome coronavirus 2 (SARS-CoV-2) named COVID-19 is causing a severe health emergency, and an individual's hormonal milieu may play an important role in both susceptibility to infection and severity of clinical course. We analyzed the role of testosterone in the immune response, and we hypothesized possible mechanisms to explain the high incidence of COVID-19 infection and a worse clinical course in elderly male patients. Testosterone may impair the immune response, and this effect could explain the greater susceptibility of men to infection. Transmembrane serine protease 2 (TMPRSS2) plays a crucial role in the entry of the virus into the respiratory epithelial cells, leading to COVID-19 disease. It is crucial to emphasize that testosterone levels and chemical castration (e.g. by androgen deprivation therapy for prostate cancer) may have contrasting roles in the phases of COVID-19 infection. Whereas low testosterone levels may be protective against the initial susceptibility (due to a restoration of immunological functions and a block of TMPRSS2), low testosterone may stimulate a worse clinical course in the advanced COVID-19 infection as it could exacerbate or activate the cytokine storm. If testosterone levels play these different roles, it is necessary to carefully identify patients for any indicated testosterone manipulation.

An Update on the Relationship of SARS-CoV-2 and Male Reproduction

Since the outbreak of the COVID-19, up to now, infection cases have been continuously rising to over 200 million around the world. Male bias in morbidity and mortality has emerged in the COVID-19 pandemic. The infection of SARS-CoV-2 has been reported to cause the impairment of multiple organs that highly express the viral receptor angiotensin-converting enzyme 2 (ACE2), including lung, kidney, and testis. Adverse effects on the male reproductive system, such as infertility and sexual dysfunction, have been associated with COVID-19. This causes a rising concern among couples intending to have a conception or who need assisted reproduction. To date, a body of studies explored the impact of SARS-CoV-2 on male reproduction from different aspects. This review aims to provide a panoramic view to understand the effect of the virus on male reproduction and a new perspective of further research for reproductive clinicians and scientists.

COVID-19 endocrinopathy with hindsight from SARS

The current COVID-19 pandemic is probably the worst the world has ever faced since the start of the new millennium. Although the respiratory system is the most prominent target of SARS-CoV-2 (the contagion of COVID-19), extrapulmonary involvement are emerging as important contributors of its morbidity and lethality. This article summarizes the impact of SARS-CoV and SARS-CoV-2 on the endocrine system to facilitate our understanding of the nature of coronavirus-associated endocrinopathy. Although new data are rapidly accumulating on this novel infection, many of the endocrine manifestations of COVID-19 remain incompletely elucidated. We, hereby, summarize various endocrine dysfunctions including coronavirus-induced new onset diabetes mellitus, hypocortisolism, thyroid hormone, and reproductive system aberrations so that clinicians armed with such insights can potentially benefit patients with COVID-19 at the bedside.

Viral infections and implications for male reproductive health

Viral infections have haunted humankind since times immemorial. Overpopulation, globalization, and extensive deforestation have created an ideal environment for a viral spread with unknown and multiple shedding routes. Many viruses can infect the male reproductive tract, with potential adverse consequences to male reproductive health, including infertility and cancer. Moreover, some genital tract viral infections can be sexually transmitted, potentially impacting the resulting offspring's health. We have summarized the evidence concerning the presence and adverse effects of the relevant viruses on the reproductive tract (mumps virus, human immunodeficiency virus, herpes virus, human papillomavirus, hepatitis B and C viruses, Ebola virus, Zika virus, influenza virus, and coronaviruses), their routes of infection, target organs and cells, prevalence and pattern of virus shedding in semen, as well as diagnosis/testing and treatment strategies. The pathophysiological understanding in the male genital tract is essential to assess its clinical impact on male reproductive health and guide future research.

A Systematic Review of the Assessment of the Presence of SARS-CoV-2 in Human Semen

Theoretically, human testes are highly expressive organs for angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 receptor. This study aimed to investigate whether the causative agent of COVID-19 is found in semen. The databases of PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar were searched using a combination of related keywords. All studies with original data, involving detection of SARS-CoV-2 in semen of male patients with COVID-19 or in those who have recovered from it, were included in the study. Six articles, including 136 samples, entered the systematic review. Most of the studies were performed in the recovery phase of COVID-19. In four articles, SARS-CoV-2 was not detected in semen, while in the other two articles semen testing showed the presence of the virus in some samples. Testicular discomfort, testicular cell damage, and spermogram disruption were also reported in some studies. We conclude that the study question cannot be answered with this number of studies. Since most of the samples were mild to moderate forms of COVID-19, it is not yet clear what the presence of the virus in semen will be in severe cases. The long-term effects are also vague. More original articles with better design and in different phases of the disease are needed to draw robust conclusions.

Spectrum of Endocrine Dysfunction and Association With Disease Severity in Patients With COVID-19: Insights From a Cross-Sectional, Observational Study

INTRODUCTION

Evidence on new-onset endocrine dysfunction and identifying whether the degree of this dysfunction is associated with the severity of disease in patients with COVID-19 is scarce.

PATIENTS AND METHODS

Consecutive patients enrolled at PGIMER Chandigarh were stratified on the basis of disease severity as group I (moderate-to-severe disease including oxygen saturation <94% on room air or those with comorbidities) (n= 35) and group II (mild disease, with oxygen saturation >94% and without comorbidities) (n=49). Hypothalamo-pituitary-adrenal, thyroid, gonadal axes, and lactotroph function were evaluated. Inflammatory and cell-injury markers were also analysed.

RESULTS

Patients in group I had higher prevalence of hypocortisolism (38.5 vs 6.8%, p=0.012), lower ACTH (16.3 vs 32.1pg/ml, p=0.234) and DHEAS (86.29 vs 117.8µg/dl, p= 0.086) as compared to group II. Low T3 syndrome was a universal finding, irrespective of disease severity. Sick euthyroid syndrome (apart from low T3 syndrome) (80.9 vs 73.1%, p= 0.046) and atypical thyroiditis (low T3, high T4, low or normal TSH) (14.3 vs 2.4%, p= 0.046) were more frequent in group I than group II. Male hypogonadism was also more prevalent in group I (75.6% vs 20.6%, p=0.006) than group II, with higher prevalence of both secondary (56.8 vs 15.3%, p=0.006) and primary (18.8 vs 5.3%, p=0.006) hypogonadism. Hyperprolactinemia was observed in 42.4% of patients without significant difference between both groups.

CONCLUSION

COVID-19 can involve multiple endocrine organs and axes, with a greater prevalence and degree of endocrine dysfunction in those with more severe disease.

T Lymphocytes and Testicular Immunity: A New Insight into Immune Regulation in Testes

The immune privilege of the testes is necessary to prevent immune attacks to gamete-specific antigens and paternal major histocompatibility complex (MHC) antigens, allowing for normal spermatogenesis. However, infection and inflammation of the male genital tract can break the immune tolerance and represent a significant cause of male infertility. Different T cell subsets have been identified in mammalian testes, which may be involved in the maintenance of immune tolerance and pathogenic immune responses in testicular infection and inflammation. We reviewed the evidence in the published literature on different T subtypes (regulatory T cells, helper T cells, cytotoxic T cells, γδ T cells, and natural killer T cells) in human and animal testes that support their regulatory roles in infertility and the orchitis pathology. While many in vitro studies have indicated the regulation potential of functional T cell subsets and their possible interaction with Sertoli cells, Leydig cells, and spermatogenesis, both under physiological and pathological processes, there have been no in situ studies to date. Nevertheless, the normal distribution and function of T cell subsets are essential for the immune privilege of the testes and intact spermatogenesis, and T cell-mediated immune response drives testicular inflammation. The distinct function of different T cell subsets in testicular homeostasis and the orchitis pathology suggests a considerable potential of targeting specific T cell subsets for therapies targeting chronic orchitis and immune infertility.

Blood molecular markers associated with COVID-19 immunopathology and multi-organ damage

COVID-19 is characterized by dysregulated immune responses, metabolic dysfunction and adverse effects on the function of multiple organs. To understand host responses to COVID-19 pathophysiology, we combined transcriptomics, proteomics, and metabolomics to identify molecular markers in peripheral blood and plasma samples of 66 COVID-19-infected patients experiencing a range of disease severities and 17 healthy controls. A large number of expressed genes, proteins, metabolites, and extracellular RNAs (exRNAs) exhibit strong associations with various clinical parameters. Multiple sets of tissue-specific proteins and exRNAs varied significantly in both mild and severe patients suggesting a potential impact on tissue function. Chronic activation of neutrophils, IFN-I signaling, and a high level of inflammatory cytokines were observed in patients with severe disease progression. In contrast, COVID-19-infected patients experiencing milder disease symptoms showed robust T-cell responses. Finally, we identified genes, proteins, and exRNAs as potential biomarkers that might assist in predicting the prognosis of SARS-CoV-2 infection. These data refine our understanding of the pathophysiology and clinical progress of COVID-19.

Body Localization of ACE-2: On the Trail of the Keyhole of SARS-CoV-2

The explosion of the new coronavirus (SARS-CoV-2) pandemic has brought the role of the angiotensin converting enzyme 2 (ACE2) back into the scientific limelight. Since SARS-CoV-2 must bind the ACE2 for entering the host cells in humans, its expression and body localization are critical to track the potential target organ of this infection and to outline disease progression and clinical outcomes. Here, we mapped the physiological body distribution, expression, and activities of ACE2 and discussed its potential correlations and mutal interactions with the disparate symptoms present in SARS-CoV-2 patients at the level of different organs. We highlighted that despite during SARS-CoV-2 infection ACE2-expressing organs may become direct targets, leading to severe pathological manifestations, and subsequent multiple organ failures, the exact mechanism and the potential interactions through which ACE2 acts in these organs is still heavily debated. Further scientific efforts, also considering a personalized approach aimed to consider specific patient differences in the mutual interactions ACE2-SARS-CoV-2 and the long-term health effects associated with COVID-19 are currently mandatory.

A Review of the Impact of COVID-19 on Male Reproduction, and its Implications on Assisted Reproductive Technology Services

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became an established pandemic in 2020. The presence of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) in male reproductive organ are considered as a potential for susceptibility of these organs to SARS-CoV-2 infection.

Review: Spermatogonia are the only cells that express ACE2 and TMPRSS2 in the testis, but the cells which co-express both genes are rare (0.05% of cells). Based on this co-expression, sperm are unlikely to be susceptible to infection by SARS-CoV-2. However, the co-expression of receptor basigin (BSG/CD147) and cathepsin L (CTSL) in primary spermatocytes, Leydig cells, myoid cells, endothelial cells, and spermatogonia might increase the testicular susceptibility to this viral infection. Testicular pain and discomfort have been reported in coronavirus disease 2019 (COVID-19) patients. Postmortem examination also reported seminiferous tubular injury, reduced Leydig cells, and mild lymphocytic inflammation in COVID-19 patients. Compensated hypogonadism has been documented while the impact of COVID-19 on the semen quality is inconclusive. There is only one study that reported the presence of SARS-CoV-2 RNA in semen but, is not supported by other studies with better methods. The association between SARS-CoV-2 and assisted reproductive technology (ART) outcome is surrounded by some uncertainties. Recommendations have been made to reduce the risk of viral transmission to patients, staff, gametes, and embryos.

Summary: There is no definite correlation between SARS-CoV-2 infection and male reproductive system. However, a high level of vigilance is still required in services which involve the reproductive system.

A comprehensive review of the impact of COVID-19 on human reproductive biology, assisted reproduction care and pregnancy: a Canadian perspective

Currently, the world is in the seventh month of the COVID-19 pandemic. Globally, infections with novel SARS-CoV-2 virus are continuously rising with mounting numbers of deaths. International and local public health responses, almost in synchrony, imposed restrictions to minimize spread of the virus, overload of health system capacity, and deficit of personal protective equipment (PPE). Although in most cases the symptoms are mild or absent, SARS-CoV-2 infection can lead to serious acute respiratory disease and multisystem failure. The research community responded to this new disease with a high level of transparency and data sharing; with the aim to better understand the origin, pathophysiology, epidemiology and clinical manifestations. The ultimate goal of this research is to develop vaccines for prevention, mitigation strategies, as well as potential therapeutics.The aim of this review is to summarize current knowledge regarding the novel SARS CoV-2, including its pathophysiology and epidemiology, as well as, what is known about the potential impact of COVID-19 on reproduction, fertility care, pregnancy and neonatal outcome. This summary also evaluates the effects of this pandemic on reproductive care and research, from Canadian perspective, and discusses future implications.In summary, reported data on pregnant women is limited, suggesting that COVID-19 symptoms and severity of the disease during pregnancy are similar to those in non-pregnant women, with pregnancy outcomes closely related to severity of maternal disease. Evidence of SARS-CoV-2 effects on gametes is limited. Human reproduction societies have issued guidelines for practice during COVID-19 pandemic that include implementation of mitigation practices and infection control protocols in fertility care units. In Canada, imposed restrictions at the beginning of the pandemic were successful in containing spread of the infection, allowing for eventual resumption of assisted reproductive treatments under new guidelines for practice. Canada dedicated funds to support COVID-19 research including a surveillance study to monitor outcomes of COVID-19 during pregnancy and assisted reproduction. Continuous evaluation of new evidence must be in place to carefully adjust recommendations on patient management during assisted reproductive technologies (ART) and in pregnancy.