Abstract: FR-PO1250
Myeloproliferative Nephropathy Unmasks a Hematologic Diagnosis
Session Information
- Onconephrology: Diagnostic Dilemmas, Therapy-Related Toxicities, and Clinical Cases
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1600 Onconephrology
Authors
- Samant, Samira Mahesh, Stanford Medicine, Stanford, California, United States
- Troxell, Megan L., Stanford Medicine, Stanford, California, United States
- Abra, Graham E., Stanford Medicine, Stanford, California, United States
Introduction
A case of myeloproliferative nephropathy prompting bone marrow biopsy, significantly altering management.
Case Description
43-year-old male bodybuilder of African ancestry with polycythemia presumed secondary to OSA (JAK2 and next-generation sequencing negative), complicated by DVTs requiring anticoagulation and intermittent phlebotomy, who presented to nephrology for elevated serum creatinine. He had normal 24-hour creatinine clearance and no proteinuria. In 2024, UACR rose to 347 mg/g with bland urinalysis, controlled diabetes (A1c 5.8%), and creatinine at baseline.
Renal biopsy showed mild diabetic nephropathy (DN) with segmental basement membrane duplication with cellular interposition, extensive arteriolar hyalinosis, and focal segmental glomerulosclerosis concerning for early myeloproliferative nephropathy or chronic thrombotic microangiopathy (TMA). He was treated with empagliflozin and losartan.
UACR increased to 1801 mg/g; he sought a second nephrology opinion at our institution. After review with hematology, bone marrow biopsy revealed hypercellularity with trilineage hematopoiesis and relative erythroid hyperplasia consistent with mutation-negative polycythemia vera (PV). Hydroxyurea was initiated without response; he switched to ruxolitinib with improvement.
Genetic testing showed APOL1 G1 heterozygosity with 2 variants of unknown significance in LAMA5, associated with increased risk of FSGS. Atypical HUS panel revealed CFHR1-CFHR3 homozygous gene deletion, but negative anti-CFH autoantibody. No evidence of systemic TMA. With cytoreductive therapy and treatment of DN with empagliflozin, losartan, finerenone, and semaglutide, UACR fell to 189 mg/g with stable creatinine.
Discussion
In cases of renal biopsy findings suggestive of myeloproliferative nephropathy without definitively diagnosed myeloproliferative neoplasm, additional hematologic testing should be pursued.