De novo CMV-associated collapsing focal segmental glomerulosclerosis in a kidney transplant recipient.

Collapsing focal segmental glomerulosclerosis (FSGS) is a variant of FSGS and is associated with severe nephrotic syndrome and acute kidney injury and can occur after kidney transplantation. The exact mechanism of collapsing FSGS after kidney transplantation is unknown, but potential causes include autoimmune diseases, certain malignancies, bisphosphonates, m-TOR inhibitors, interferon-alpha, HIV infection, and other viruses. We describe a case of de novo Cytomegalovirus (CMV)-associated collapsing FSGS in a kidney transplant recipient with a UL97 phosphotransferase mutation that was successfully treated with intravenous ganciclovir, intravenous immunoglobulin, and steroids.