Cyclosporine therapy during the COVID-19 pandemic.

To the Editor : The rapid dissemination of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 pandemic raised concerns related to possible risks associated with the immunosuppressive treatment of autoimmune diseases. , Cyclosporine is an immunosuppressive drug that acts selectively on T cells by inhibiting calcineurin phosphorylase. It is widely used in dermatology, rheumatology, nephrology, ophthalmology, and transplantation.

Despite its immunosuppressive activity, infections are not a common adverse effect. Some reports of severe infections in patients treated with cyclosporine have been published, but several data sources indicate that the risk of common infections in patients receiving cyclosporine is low and comparable to that in individuals receiving placebo. In a study of 225 patients receiving cyclosporine for 12 months, none of the patients experienced the reactivation or a new onset of viral infections, including varicella zoster virus, herpes simplex 1, herpes simplex 2, Ebstein-Barr, cytomegalovirus, and HIV, or other infectious diseases. It was suggested that cyclosporine may exert a therapeutic effect in patients with selected viral diseases.

Numerous in vitro data also indicate that cyclosporine has wide-spectrum antiviral properties. It inhibits the replication of viruses such as the hepatitis B virus, hepatitis C virus, and HIV virus. Cyclosporine also inhibits the replication of influenza A virus, West Nile virus, Rift Valley fever virus, and Zika virus through blocking the interaction of cellular cyclophilins with viral proteins and inhibiting viral RNA synthesis.

The effect of cyclosporine on coronaviruses, other than the new SARS-CoV2, has been extensively studied. The attention was especially paid to 2 life-threatening coronaviruses in humans, SARS-CoV and Middle East respiratory syndrome-related coronavirus (MERS-CoV). The data showed that cyclosporine reduced MERS-CoV and SARS-COV replication in vitro. A similar inhibiting effect was observed in case of other coronaviruses, including human coronavirus 229E, transmissible gastroenteritis coronavirus, feline coronavirus, porcine epidemic diarrhea virus, and mouse hepatitis virus. Promising in vitro results led some authors to the speculation that cyclosporin may be an interesting treatment option for SARS.

No literature data are available on the effect of cyclosporine on SARS-CoV2, which causes COVID-19, but available data allow us to hypothesize that patients who receive cyclosporine treatment for dermatologic autoimmune diseases may benefit from its antiviral activity. They are probably at a lower risk of developing severe symptoms related to COVID-19 compared with patients who receive other treatments for their conditions. An open question remains whether the antiviral activity of cyclosporine may impair the development of immunity to coronaviruses and, as a consequence, increase vulnerability to future infections.