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

Potential mechanisms of SARS-CoV-2 action on male gonadal function and fertility: Current status and future prospects

The novel coronavirus was recognised in December 2019 and caught humanity off guard. The virus employs the angiotensin‐converting enzyme 2 (ACE2) receptor for entry into human cells. ACE2 is expressed on different organs, which is raising concern as to whether these organs can be infected by the virus or not. The testis appears to be an organ enriched with levels of ACE2, while the possible mechanisms of involvement of the male reproductive system by SARS‐CoV‐2 are not fully elucidated. The major focus of the present studies is on the short‐term complications of the coronavirus and gains importance on studying the long‐term effects, including the possible effects of the virus on the male reproductive system. The aim of this review was to provide new insights into different possible mechanisms of involvement of male gonads with SARS‐CoV‐2 including investigating the ACE2 axis in testis, hormonal alterations in patients with COVID‐19, possible formation of anti‐sperm antibodies (ASA) and subsequently immunological infertility as a complication of SARS‐CoV‐2 infection. Finally, we suggest measuring the sperm DNA fragmentation index (DFI) as a determiner of male fertility impairment in patients with COVID‐19 along with other options such as sex‐related hormones and semen analysis. Invasion of SARS‐CoV‐2 to the spermatogonia, Leydig cells and Sertoli cells can lead to sex hormonal alteration and impaired gonadal function. Once infected, changes in ACE2 signalling pathways followed by oxidative stress and inflammation could cause spermatogenesis failure, abnormal sperm motility, DNA fragmentation and male infertility.

Is There a Link between Bisphenol A (BPA), a Key Endocrine Disruptor, and the Risk for SARS-CoV-2 Infection and Severe COVID-19?

Infection by the severe acute respiratory syndrome (SARS) coronavirus-2 (SARS-CoV-2) is the causative agent of a new disease (COVID-19). The risk of severe COVID-19 is increased by certain underlying comorbidities, including asthma, cancer, cardiovascular disease, hypertension, diabetes, and obesity. Notably, exposure to hormonally active chemicals called endocrine-disrupting chemicals (EDCs) can promote such cardio-metabolic diseases, endocrine-related cancers, and immune system dysregulation and thus, may also be linked to higher risk of severe COVID-19. Bisphenol A (BPA) is among the most common EDCs and exerts its effects via receptors which are widely distributed in human tissues, including nuclear oestrogen receptors (ERα and ERβ), membrane-bound oestrogen receptor (G protein-coupled receptor 30; GPR30), and human nuclear receptor oestrogen-related receptor gamma. As such, this paper focuses on the potential role of BPA in promoting comorbidities associated with severe COVID-19, as well as on potential BPA-induced effects on key SARS-CoV-2 infection mediators, such as angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). Interestingly, GPR30 appears to exhibit greater co-localisation with TMPRSS2 in key tissues like lung and prostate, suggesting that BPA exposure may impact on the local expression of these SARS-CoV-2 infection mediators. Overall, the potential role of BPA on the risk and severity of COVID-19 merits further investigation.

Coronavirus: A possible cause of reduced male fertility

In lately December 2019, a novel coronavirus (SARS-CoV-2) outbreak occurred in Wuhan, PR China. It is a high contagious virus that has threatened human health worldwide. SARS-CoV-2 infection, termed COVID-19, causes rapidly developing lung lesions that can lead to multiple organ failure in a short period. Whenever a novel virus emerges, reproductive risk assessments should be performed after infection. In this review, we show that male fertility might be damaged by coronavirus associated with (i) direct cytopathic effects derived from viral replication and viral dissemination in the testis; and (ii) indirect damage to male fertility derived from immunopathology. In this review, we briefly describe the impaired fertility of humans and animals infected with coronaviruses to deduce the impact of the new coronavirus on male fertility. Together with information related to other coronaviruses, we extrapolate this knowledge to the new coronavirus SARS-CoV-2, which may have a significant impact on our understanding of the pathophysiology of this new virus.

Testis and blood-testis barrier in Covid-19 infestation: role of angiotensin-converting enzyme 2 in male infertility

Severe acute respiratory syndrome coronavirus 2 (SARS- CoV-2) that causes COVID-19 infections penetrates body cells by binding to angiotensin-converting enzyme-2 (ACE2) receptors. Evidence shows that SARS-CoV-2 can also affect the urogenital tract. Hence, it should be given serious attention when treating COVID-19-infected male patients of reproductive age group. Other viruses like HIV, mumps, papilloma and Epstein-Barr can induce viral orchitis, germ cell apoptosis, inflammation and germ cell destruction with attending infertility and tumors. The blood-testis barrier (BTB) and blood-epididymis barrier (BEB) are essential physical barricades in the male reproductive tract located between the blood vessel and seminiferous tubules in the testes. Despite the significant role of these barriers in male reproductive function, studies have shown that a wide range of viruses can still penetrate the barriers and induce testicular dysfunctions. Therefore, this mini-review highlights the role of ACE2 receptors in promoting SARS-CoV-2-induced blood-testis/epididymal barrier infiltration and testicular dysfunction.

Novel coronavirus disease 2019 (COVID-19) non-respiratory involvement

Background

Coronavirus disease 2019 (COVID-19) is a newly emerging pandemic that affected millions of people worldwide caused by novel coronavirus SARS-CoV-2. The first cases reported suffered from respiratory symptoms.

Main body

Various extrapulmonary manifestations were linked to COVID-19 in several reports including cardiovascular, genitourinary, gastrointestinal, and skin. It is important that every clinician should be aware of these non-respiratory manifestations for early diagnosis and prompt management. This review aims to summarize the different extrapulmonary manifestations of COVID-19 disease and highlight the importance of multidisciplinary care.

Conclusion

COVID-19 is a disease of multi-organ involvement. Manifestations may vary depending on which organ is involved.

Renin Angiotensin System, COVID-19 and Male Fertility: Any Risk for Conceiving?

The current knowledge concerning the connection between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the renin-angiotensin system (RAS) system in the male reproductive apparatus is still limited, so dedicated studies are urgently required. Concerns about the male fertility consequences of SARS-CoV-2 infection have started to emerge, since epidemiologic studies observed that this coronavirus affects male patients more frequently and with increased severity, possibly because of the hormone-regulated expression of angiotensin-converting enzyme 2 (ACE2) receptor. A disturbance in fertility is also expected based on studies of the previous SARS-CoV infection, which targets the same ACE2 receptor when entering the host cells. In addition, bioinformatics analyses reveal the abundant expression of ACE2 receptor in the male reproductive tissues, particularly in the testis. It has been proposed that pharmacological intervention favoring the angiotensin-(1-7)/ACE2/Mas receptor pathway and increasing ACE2 expression and activity could greatly prevent inflammatory lesions in this area. Finally, in laboratories performing assisted reproductive technologies it is recommended that more attention should be paid not only to sperm quality but also to safety aspects. Data about the potential infectivity of seminal fluid are in fact conflicting and do not exclude risks for both personnel and patients. The potential infectivity of SARS-CoV-2 in reproductive male tissues should be strongly considered and further investigated for the proper management of in vitro fertilization procedures.

Imaging Diagnostics and Pathology in SARS-CoV-2-Related Diseases

In December 2019, physicians reported numerous patients showing pneumonia of unknown origin in the Chinese region of Wuhan. Following the spreading of the infection over the world, The World Health Organization (WHO) on 11 March 2020 declared the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak a global pandemic. The scientific community is exerting an extraordinary effort to elucidate all aspects related to SARS-CoV-2, such as the structure, ultrastructure, invasion mechanisms, replication mechanisms, or drugs for treatment, mainly through in vitro studies. Thus, the clinical in vivo data can provide a test bench for new discoveries in the field of SARS-CoV-2, finding new solutions to fight the current pandemic. During this dramatic situation, the normal scientific protocols for the development of new diagnostic procedures or drugs are frequently not completely applied in order to speed up these processes. In this context, interdisciplinarity is fundamental. Specifically, a great contribution can be provided by the association and interpretation of data derived from medical disciplines based on the study of images, such as radiology, nuclear medicine, and pathology. Therefore, here, we highlighted the most recent histopathological and imaging data concerning the SARS-CoV-2 infection in lung and other human organs such as the kidney, heart, and vascular system. In addition, we evaluated the possible matches among data of radiology, nuclear medicine, and pathology departments in order to support the intense scientific work to address the SARS-CoV-2 pandemic. In this regard, the development of artificial intelligence algorithms that are capable of correlating these clinical data with the new scientific discoveries concerning SARS-CoV-2 might be the keystone to get out of the pandemic.

[SARS-CoV-2 infection: implications for sexual and reproductive health. A position statement of the Asociación Española de Andrología, Medicina Sexual y Reproductiva (ASESA)]

OBJECTIVE

The main objective of this revision is to summarize the current existing evidence of the potential adverse effects of SARS-CoV-2 on the male reproductive system and provide the recommendations of the Asociación Española de Andrología, Medicina Sexual y Reproductiva (ASESA) concerning the implications of COVID-19 infection in the management of male infertilty patients and testicular endocrine dysfunction.

METHODS

A comprehensive systematic literature search of the databases of PubMed, Web of Science, Embase, Medline, Cochrane and MedRxiv, was carried out.

RESULTS

The presence of orchitis as a potential complication of the infection by SARS-CoV-2 has not yet been confirmed. One study reported that 19% of males with COVID-19 infection had scrotal symptoms suggestive of viral orchitis which could not be confirmed. It is possible that the virus, rather than infecting the testes directly, may induce a secondary autoimmune response leading to autoimmune orchitis. COVID-19 has been associated with coagulation disorders and thus the orchitis could be the result of segmental vasculitis. Existing data concerning the presence of the virus in semen are contradictory. Only one study reported the presence of RNA in 15.8% of patients with COVID-19. However, the presence of nucleic acid or antigen in semen is not synonyms of viral replication capacity and infectivity. It has been reported an increase in serum levels of LH in males with COVID-19 and a significant reduction in the T/LH and FSH/LH ratios, consistent with subclinical hypogonadism.

CONCLUSIONS

The findings of recent reports related to the potential effects of COVID-19 infection on the male reproductive system are based on poorly designed, small sample size studies that provide inconclusive, contradictory results. Since there still exists a theoretical possibility of testicular damage and male infertilty as a result of the infection by COVID-19, males of reproductive age should be evaluated for gonadal function and semen analysis. With regard to the sexual transmission of the virus, there is not sufficient evidence to recommend asymptomatic couples to abstein from having sex in order to protect themselves from being infected by the virus. Additional studies are needed to understand the long-term effects of SARS-CoV-2 on male reproductive function, including male fertility potential and endocrine testicular function.