Even mild or moderate COVID-19 illness could change the level of proteins related to male reproductive function that may impair fertility, according to a small study led by researchers at the Indian Institute of Technology (IIT) Bombay.
The research, published last week in the journal ACS Omega, analysed protein levels in semen of men who have recovered from COVID-19.
Although SARS-CoV-2, the virus that causes COVID-19, mainly affects the respiratory system, the virus, and the body’s response to it, also damages other tissues, according to the researchers.
Recent evidence indicates that COVID-19 infection can reduce male fertility, and the virus has been detected in male reproductive organs, they said.
The team, including researchers from Jaslok Hospital and Research Centre in Mumbai at IIT-B, wondered if COVID-19 infection could have long-term impacts on the male reproductive system.
The researchers compared the levels of proteins in the semen of healthy men and those who previously had mild or moderate cases of COVID-19.
They analysed semen samples from 10 healthy men and 17 men who had recently recovered from COVID-19. None of the men, who ranged in age from 20 to 45, had a prior history of infertility.
The team found that the recovered men had significantly reduced sperm count and motility, and fewer normally shaped sperm, than those who had not had COVID-19.
When the researchers analysed semen proteins using liquid chromatography-tandem mass spectrometry, they found 27 proteins at higher levels and 21 proteins at lower levels in COVID-19-recovered men compared with the control group.
The researchers said many of the proteins were involved in reproductive function.
Two of the fertility-related proteins, semenogelin 1 and prosaposin, were present at less than half their levels in the semen of the COVID-19-recovered group than in the semen of controls they said.
The findings suggest that SARS-CoV-2 has direct or indirect effects on male reproductive health that linger after recovery, the researchers said.
The work might also reveal insights into the physiological processes associated with disease or injury of human reproduction in recovered men, they added.
However, the researchers added that larger studies should be done to confirm the findings, and a control group of men who recently recovered from other flu-like illnesses should be included to ensure that the findings are specific for COVID-19.