COVID-19-Related Collapsing Glomerulopathy and Thrombotic Microangiopathy in Kidney Transplant Recipients: A Case Report and Literature Review.

We present a case of collapsing glomerulopathy (CG) and thrombotic microangiopathy (TMA) associated with COVID-19 in an Asian kidney transplant recipient who does not have the APOL1 gene variant, and we conduct a literature review. The patient presented with progressive renal function decline following a negative COVID-19 nucleic acid test, accompanied by TMA manifestations such as thrombocytopenia and peripheral blood schistocytes. The renal biopsy conducted after plasma exchange revealed collapsing focal segmental glomerulosclerosis, along with acute tubulointerstitial nephritis and minor microangiopathic changes. The patient underwent cyclic eculizumab therapy and ultimately died of acute pulmonary embolism. Our findings indicate that kidney transplant recipients still may experience severe renal impairment even after testing negative for COVID-19 nucleic acid. COVID-19 can not only directly damage transplanted kidneys, but also indirectly harm transplanted kidneys by causing the release of cytokines and inflammation. COVID-19-related TMA and CG may be a continuous pathological process, and prolonged TMA may lead to the development of CG with a worse prognosis. It is also possible that CG and TMA coexist when patients present with acute kidney injury (AKI). Therefore, even a mild COVID-19 infection can have serious consequences for kidney transplant recipients. Vigilance for TMA and CG should be maintained in the presence of AKI of unknown cause.