Abstract: TH-PO0523
Lysozyme-Induced Nephropathy (LyN): A Rare Cause of CKD in a Patient with Chronic Myelomonocytic Leukemia 1 (CMML-1)
Session Information
- Glomerular Diseases: IgAN, IgA Vasculitis, and More
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Berrios Mendez, Jose Javier, University of Virginia, Charlottesville, Virginia, United States
- Caza, Tiffany, Arkana Labs, Little Rock, Arkansas, United States
- Radhakrishnan, Yeshwanter, University of Virginia, Charlottesville, Virginia, United States
Introduction
LyN is a known rare cause of Acute Kidney Injury or progressive CKD due to overproduction of lysozyme that could be seen in granulomatous diseases or certain malignancies. Lysozyme is freely filtered by the glomeruli and if produced in excess will cause proximal tubulopathy with characteristic hyper eosinophilic intracytoplasmic inclusions.
Case Description
87 year old female with past medical history of CMML-1, hypertension, subdural hemorrhages, focal seizures, severe aortic stenosis post TAVR referred to nephrology for progressive CKD. Current meds- allopurinol, clopidogrel, zonisamide, levothyroxine. CMML-1 was diagnosed in 2021 with 7% blasts in a bone marrow biopsy and was on observation only. Renal function had been declining since 2021 shortly after CMML-1 diagnosis with her serum creatinine at 1.0 in 2020 and recently at 2.5 with an eGFR average of 15-20 ml/min. Urine showed moderate albuminuria at 130 mg/g and microscopic hematuria since 2023. CT abdomen showed bilateral normal sized kidneys with mild renal artery stenosis. Lysozyme levels came back at >38.6 mcg/ml (normal: 2-6 mcg/ml). She underwent a kidney biopsy which confirmed the diagnosis of LyN after immunohistochemical stain for lysozyme was performed along with findings of severe arterial nephrosclerosis. She was initiated on hydroxyurea by hematology due to the LyN in addition to supportive care for advanced CKD.
Discussion
LyN remains an exceedingly rare cause of AKI, AKI on CKD or CKD. In addition, the population it usually affects can have multiple causative etiologies and LyN can be easily overlooked. High index of suspicion and performing a native kidney biopsy still remains an essential component for the diagnosis.