Kidney Week

Abstract: FR-PO0722

T-Cell Large Granular Lymphocytic Leukemia (T-LGL) as a Potential Trigger for Collapsing Glomerulopathy in a Patient with an APOL1 High-Risk Genotype

Session Information

• Glomerular Diseases: Membranous Nephropathy, FSGS, and Podocytopathies
  October 23, 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

• Vadpey, Omid, University of California San Francisco, San Francisco, California, United States

Omid Vadpey, MD

• Urisman, Anatoly, University of California San Francisco, San Francisco, California, United States

Anatoly Urisman, MD, PhD

• Ravi, Divya, University of California San Francisco, San Francisco, California, United States

Divya Ravi, MBBS

• He, Chenyin, West Coast Kidney, Oakland, California, United States

Chenyin He, MD

• Loeb, Gabriel, University of California San Francisco, San Francisco, California, United States

Gabriel Loeb, MD, PhD

• Hsu, Raymond K., University of California San Francisco, San Francisco, California, United States

Raymond K. Hsu, MD, MA

• Showers, Christopher R., University of California San Francisco, San Francisco, California, United States

Christopher R. Showers, MD

Introduction

Biallelic APOL1 risk alleles are a genetic risk factor for FSGS. In individuals with these alleles, a second trigger is hypothesized to provoke collapsing FSGS. Reported hits include viral infections and autoimmune diseases, both linked with high interferon activity. Paraneoplastic glomerular disease has also been described, including FSGS in hematologic malignancies. We report a case of collapsing FSGS in a patient with biallelic APOL1 risk alleles and T-cell leukemia, highlighting a novel potential trigger in APOL1-associated kidney disease.

Case Description

A 32-year-old male presented with fever, edema, and found to have an AKI with creatinine of 4.8 mg/dl (baseline 0.9 mg/dl), >10-gram proteinuria, hypoalbuminemia, and pancytopenia. A serologic workup was unrevealing; a kidney biopsy showed collapsing FSGS with diffuse foot process effacement (Figure). Viral studies were negative for HIV, COVID-19, Parvovirus B-19, EBV, and CMV. Genetic testing was positive for biallelic APOL1 risk alleles (G1/G1). CT revealed a mediastinal mass and bone marrow biopsy showed T-cell large granular lymphocytic leukemia (LGL). Dialysis was initiated for volume overload. Treatment with high-dose steroids led to initial hematologic improvement and gradual liberation from dialysis within 3 months. Cancer treatment included methotrexate, rituximab, and subsequently clinical trial enrollment. 24 months from presentation, with controlled LGL, has a creatinine 1.4-1.6 mg/dL, proteinuria 2-4 g/day before initiation of sparsentan.

Discussion

Our case highlights the potential interaction between LGL and APOL1 biallelic risk alleles as a trigger for collapsing FSGS. LGL is commonly associated with autoimmune disease and increased cytokine production including interferons, which we hypothesize contributed to the FSGS in our patient. Prior reports of paraneoplastic glomerular disease have been limited by lack of genetic testing. In the absence of viral infections or autoimmune disease, a search for underlying hematologic malignancy in patients with collapsing FSGS may be considered.