In an article recently published in Frontiers in Endocrinology, scientists deciphered the possibility of cryopreserving sperm of coronavirus disease 2019 (COVID-19) patients. The article also proposes some suggestions to help cryobanks perform the appropriate procedure to preserve the sperm of COVID-19 patients.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of COVID-19, has been found to induce various reproductive abnormalities, including reduced sperm production and structural alteration in testicular tissues, sex hormone disorders, and poor sperm quality.
In the male reproductive system, SARS-CoV-2 may impair the blood-testis barrier to directly attack the germ cells and disrupt the hypothalamic-pituitary-testicular axis to alter the secretion of sex hormones. In addition, the virus-induced oxidative stress, inflammation, and infection-related fever may disrupt the overall functioning of the reproductive system.
Regarding the presence of SARS-CoV-2 in semen, most studies have reported non-affirmative. Only a few studies have detected viral RNA in the semen. Because of the overlapping of distal urinary and reproductive tracts in males, the viral RNA in the semen could possibly appear from urinary shedding. In addition, the evidence supporting the presence of SARS-CoV-2 in testicular tissues is lacking.
Possibility of sperm cryopreservation
During the initial phase of the COVID-19 pandemic, various fertility procedures, including cryopreservation of sperm and in vitro fertilization (IVF), have been suspended by many cryobanks and fertility centers because of the fear of work-related viral spread among staff and patients. However, for patients with cancer or other critical illnesses, cryopreservation of sperm is an urgent requirement before the commencement of therapeutic interventions because many therapies can cause temporary or permanent infertility in male patients.
Studies have detected more than 27 viruses in the semen, including human immunodeficiency virus (HIV), Zika, and mumps. Some viruses, such as the Zika virus, can even be detected in the sperm of asymptomatic patients for up to one year following recovery.
Laboratory staff working in cryobanks or fertility centers are at high risk of direct viral exposure during the processing of semen samples collected from virus-infected individuals. Moreover, cross-contamination between infected and non-infected samples can occur during the cryo-storage stage as many viruses can survive for a long time in the ultra-low temperature of liquid nitrogen. Thus, semen samples containing infectious virus should be treated with extra precaution to avoid unexpected viral exposure and cross-contamination.
Procedures to follow during cryopreservation of sperm from COVID-19 patients
Although the risk of SARS-CoV-2 infection in semen is very low, precautions should still be taken in cryobanks to avoid unnecessary health hazards. In the current article, the scientists have suggested some precautionary procedures based on the expert opinion available in the literature.
Cryobanks planning to preserve sperms of COVID-19 patients must invite reproductive health authorities to evaluate the laboratory conditions and facilities. They should train their staff for suitable precautionary procedures and arrange a separate laboratory for collecting sperm from COVID-19 patients.
To minimize direct patient contact, online platforms could be used to collect epidemiological and medical history from patients with acute SARS-CoV-2 infection. Semen samples should be analyzed via reverse transcription-polymerase chain reaction (RT-PCR) to detect SARS-CoV-2. Afterward, SARS-CoV-2-negative samples should be collected in high-security cryo-vials and stored in vapor-phase liquid nitrogen.
Given the possibility of long-lasting presence of SARS-CoV-2 in the body, COVID-19 recovered patients should be provided with cryopreservation facilities at least 3 months after the disappearance of symptoms. Specifically, this interval should be extended by 6 months or more for patients with long-COVID. In non-emergency conditions, sperm cryopreservation of patients with re-infection should be postponed.
In laboratories dealing with physiological and pathological conditions of the male reproductive system, class II biosafety cabinet should be utilized for emergency sperm cryopreservation of COVID-19 patients with other critical illnesses, such as cancer. Immediately after examining, processing, and storing the sperm, all equipment should be properly disposed of.
Given that SARS-CoV-2 could be present in other tissues, direct freezing of sperm collected by surgery should be avoided. All sperm samples should be washed repeatedly and examined for SARS-CoV-2 before cryopreservation.
It is highly recommended to avoid the preservation of SARS-CoV-2-positive sperms. However, in emergency conditions where further sampling of semen could not be possible, virus-positive samples should be washed with a double-density gradient followed by a swim-up. These procedures help dilute the virus before cryopreservation.