Case Report of COVID-19 Infection After Kidney Transplant Treated With Casirivimab-Imdevimab and Mycophenolate Mofetil Changed to Everolimus

BACKGROUND: Casirivimab-imdevimab is a cocktail of 2 monoclonal antibodies designed to prevent infection by SARS-CoV-2, the virus that causes COVID-19. Casirivimab-imdevimab has been approved in Japan for treating mild to moderate COVID-19; however, to our knowledge, there are no reports of its use after kidney transplant from a live donor. Everolimus, an antineoplastic chemotherapy drug, is expected to be effective in inhibiting the spread of SARS-CoV-2 and preventing its replication, which may facilitate treatment. Here, we report a case of COVID-19 infection after kidney transplant that was initially treated with casirivimab-imdevimab and mycophenolate mofetil but was later changed to everolimus. CASE REPORT: A 47-year-old man underwent living donor kidney transplant from his mother in 2017. Immunosuppression therapy was underway through the administration of tacrolimus, mycophenolate mofetil, and methylprednisolone. In early September 2021, he was diagnosed as having COVID-19 and was hospitalized on day 3. On hospitalization, mycophenolate mofetil was discontinued and casirivimab-imdevimab and heparin were started. The patient started an everolimus regimen on day 5. The clinical course was successful without rejection. There was no exacerbation of COVID-19; the patient's serum creatinine levels and renal function had otherwise remained stable. CONCLUSIONS: We could safely treat a patient with casirivimab-imdevimab after kidney transplant. It is suggested that casirivimab-imdevimab can prevent COVID-19 from becoming severe and can be administered without worsening renal function. In addition, everolimus may have inhibited the spread of the virus and prevented it from replicating.