Minimal Change Disease Following B-Cell Maturation Antigen-Directed Chimeric Antigen Receptor T-Cell Therapy.

Acute kidney injury (AKI) is a well-recognized complication of chimeric antigen receptor (CAR) T-cell therapy, typically attributed to cytokine release syndrome and acute tubular injury. However, glomerular disease post CAR-T cell is rare. We report a case of minimal change disease presenting with AKI and nephrotic-range proteinuria 3 weeks after B-cell maturation antigen-directed CAR-T cell therapy, ciltacabtagene autoleucel, in a patient with relapsed refractory multiple myeloma. The kidney biopsy revealed diffuse podocyte foot process effacement and a predominance of CD4+ T cells with potential on-target, off-tumor effect of B-cell maturation antigen-directed CAR-T cell therapy, leading to podocyte injury. The patient received one dose of rituximab along with a short course of corticosteroid and had complete kidney recovery by week 4 of therapy. This report emphasizes the need for further investigation into the mechanism of kidney toxicity following CAR-T cell therapy, and potential benefits and risks of immunosuppressive therapy in this context.