Kidney Week

Abstract: TH-PO1154

Fibrillar IgG-Lambda Deposition in Chronic Lymphocytic Leukemia

Session Information

• Onconephrology: Emerging Biomarkers, Preclinical Models, Clinical Challenges, and Therapeutic Strategies
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Onconephrology

• 1600 Onconephrology

Authors

• Liben, Michael, Weill Cornell Medicine, New York, New York, United States

Michael Liben, MD

• Yang, Yihe, Weill Cornell Medicine, New York, New York, United States

Yihe Yang, MD, MS

• Gutgarts, Victoria, Sloan-Kettering Institute, New York, New York, United States

Victoria Gutgarts, MD

Introduction

Renal involvement of Chronic Lymphocytic Leukemia (CLL) is not uncommon, however it very rarely manifests as fibrillar IgG-lambda deposition. We report a case of concomitant proteinuria, hematuria, and acute kidney injury in a patient with untreated CLL found to have fibrillar IgG-lambda deposits on kidney biopsy.

Case Description

72-year-old male with prostate cancer status post radiation therapy, CLL conservatively managed on observation for 7 years, is referred to the renal clinic for worsening microscopic hematuria. Given history of prostate cancer, urologic evaluation was initially pursued with negative computerized tomography urogram and cystoscopy. Laboratory workup showed an elevated urine protein-to-creatinine ratio of 3.6grams/24hours, a spot urine microalbumin-to-creatinine ratio of 2.1g/g, and an elevated serum creatinine to 1.6(0.7-1.3)mg/dL from a prior baseline of 1.1mg/dL 6 months ago. Urine sediment showed >300 protein, moderate blood, and 11-25 Red Blood Cells per high power field. Further serologic testing showed an elevated IgG Lambda with a normal Kappa-to-Lambda ratio, albumin of 3.9(3.8-5.0)g/dL, and a stable white blood cell count of 36(4-11)10³uL. He underwent a native kidney biopsy to investigate CLL involvement versus a potential monoclonal gammopathy of renal significance. Kidney biopsy showed glomerulopathy with monotypic, DNAJB9-negative, fibrillar IgG-lambda deposits and an atypical lymphocytic infiltrate in the kidney parenchyma, predominantly CD20-positive B cells with frequent co-expression of CD5. Bone marrow biopsy revealed >70% CLL involvement and he is planned for cancer-directed therapy.

Discussion

Kidney biopsy is paramount when CLL is being observed without treatment and there are signs of decline in kidney function, proteinuria, and hematuria. This case highlights the rare finding of fibrillar IgG-lambda renal deposition in CLL.