Urinary Mulberry Cells as a Biomarker of the Efficacy of Enzyme Replacement Therapy for Fabry Disease

Mulberry cells are often present in the urinary sediments of patients with Fabry disease (FD). We herein report two patients with FD undergoing enzyme replacement therapy (ERT). A 41-year-old man was diagnosed based on lack of α-galactosidase A activity. ERT was subsequently administered. A 40-year-old woman was diagnosed based on urinary Mulberry cells and genetic testing, and ERT was initiated. While the renal function of the male patient deteriorated, the Mulberry cells disappeared in the female patient after ERT was administered. The detection of urinary Mulberry cells can contribute to the diagnosis as well as serve as a biomarker for the response to treatment.