ABSTRACT
Kidney transplant recipients who develop coronavirus disease 2019 (COVID-19) are at increased risk of life-threatening illness, which often requires reducing immunosuppression despite the potential risk of causing an allograft rejection. Herein, we describe the clinical presentation and course of a kidney transplant recipient who acquired COVID-19 and was hospitalized with severe symptoms and hypoxemia. Upon admission, the patient was found to have elevated de novo donor-specific antibodies (DSA) yielding a positive cytotoxicity crossmatch and concurrent elevated plasma donor-derived cell-free DNA (dd-cfDNA) level, indicating a possible ongoing rejection despite improvement in his serum creatinine. Because of persistent positive COVID-19 tests and stable serum creatinine, a kidney allograft biopsy was initially deferred and his dd-cfDNA and DSA were monitored closely postdischarge. Three months later, because of persistent elevated dd-cfDNA and positive DSA, a kidney allograft biopsy was performed, which showed chronic active antibody-mediated rejection. Accordingly, the patient was treated with intravenous immunoglobulin and his maintenance immunosuppressive regimen was increased.