Antibodies to angiotensin-converting enzyme 2 in infertile patients with a history of COVID-19 and in fertile women

Angiotensin-converting enzyme 2 (ACE2) is a key component of the renin-angiotensin system (RAS) that affects fertility in women. Antibodies against ACE2 have predictive value for COVID-19 and may contribute to RAS dysregulation and reproductive failure.

Objective: To investigate the prevalence and levels of anti-ACE2 autoantibodies in infertile patients with a history of COVID-19 and in fertile women.

Materials and methods: Serum anti-ACE2 autoantibodies (M, G) were determined by ELISA in infertile patients with a history of COVID-19 (group 1, n=121), without a history of COVID-19 (group 2, n=79), and in fertile women (group 3, n=80). The association between antibodies against ACE2, SARS-CoV-2, thyroid antigens, and hormones was investigated.

Results: Patients in groups 1 and 2 had higher rates of inflammatory gynecologic diseases, pelvic surgery, spontaneous miscarriages, and thyroid pathology than those in group 3. Anti-ACE2 antibodies were detected more frequently (40.5% and 38.8 %) and had higher levels in infertile patients than in fertile women (20%). Women with a history of COVID-19 were more likely to have anti-ACE2 IgG. Antibodies against ACE2 were significantly correlated with those against FSH.

Conclusion: Patients with infertility, irrespective of a history of COVID-19, have a higher prevalence and higher anti-ACE2 antibody levels than fertile women. Anti-ACE2 antibodies are associated with primary and secondary infertility, and may be involved in the pathophysiology of infertility.