Zebra Bodies on Renal Biopsy: Fabry Disease or Not Fabry? A Tale of Two Cases

Abstract

Background: Zebra bodies are intracellular lamellar inclusions detected by electron microscopy (EM) on renal biopsy, classically found in Fabry disease. This EM finding prompts genetic testing for α-galactosidase A enzyme deficiency to diagnose Fabry disease, and thus consider enzyme replacement therapy. Zebra bodies have also been associated with certain medications, including statins and hydroxychloroquine. We present two contrasting cases, both presented within a year of each other with zebra bodies found in renal biopsy. Case Presentations Case 1: An 83-year-old lady with type II diabetes mellitus and hypertension was presumed to have diabetic or hypertensive nephropathy, however in ruling out alternative causes, was found to have asymptomatic myeloma. Renal biopsy to detect renal amyloidosis or myeloma kidney instead found zebra bodies on EM. Genetic testing confirmed Fabry disease. She was managed conservatively. Case 2: This contrasts with an 80-year-old woman with rapid decline in her renal function following coronary angiography. Renal biopsy showed hypertensive nephropathy on light microscopy, and zebra bodies on EM. She tested negative for Fabry disease. She was taking sertraline, and had previously been on atorvastatin, but this had been stopped four years prior to the biopsy. Conclusion: Drug-induced renal phospholipidosis is an important differential diagnosis to be considered in cases with zebra bodies that are negative for Fabry disease. It is unclear for how long a patient needs to be taking a culprit medication to develop these changes, and whether they may persist many years later. From our findings, it is clear that more research is needed to identify alternative causes of zebra bodies to guide earlier diagnosis and treatment, which would improve outcomes.