Abstract: FR-PO249
Lymphocytic Infiltrates on Kidney Biopsy of a Patient with AKI and Chronic Lymphocytic Leukemia: Interstitial Nephritis or Infiltration by Leukemia?
Session Information
- Onconephrology: From AKI to CKD and Everything in Between
November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Naranjo, Christopher D., University of Miami, Coral Gables, Florida, United States
- Valdes Sanchez, Chavely, University of Miami, Coral Gables, Florida, United States
- Zuo, Yiqin, University of Miami, Coral Gables, Florida, United States
- Munoz Mendoza, Jair, University of Miami, Coral Gables, Florida, United States
Introduction
Chronic lymphocytic leukemia (CLL) is the most common adult leukemia. AKI has been reported in patients with CLL due to hypercalcemia, tumor lysis syndrome, or obstructive nephropathy. Infiltration of organs by CLL can occur, however, kidney involvement is unusual.
Case Description
A 60-year-old female with history of hypertension on treatment with lisinopril and HCTZ, gastroesophageal reflux recently on esomeprazole, and CLL with trisomy 12 and 14:19 translocation, on treatment with Ibrutinib for 5 years, was found to have worsening kidney function. In the ER, she reported abdominal discomfort and bloating for one month. On physical exam she had bilateral lower extremity edema. Three months earlier, she had a creatinine of 0.98 mg/dL. On current presentation, her creatinine was 5.27 mg/dL and potassium was 2.9 mmol/L. UA revealed proteinuria and pyuria. Spot UPCR was 400 mg/g. A kidney ultrasound showed normal size kidneys. A kidney biopsy was performed which showed acute granulomatous tubulointerstitial nephritis (TIN) with extensive interstitial lymphocytic infiltrate and scattered interstitial eosinophils. Evaluation by a hematopathologist confirmed involvement of renal parenchyma by CLL. By immunohistochemistry, lymphoma cells were positive for PAX5, CD20, and CD5. Treatment was initiated with prednisone. Ibrutinib was discontinued and she was started on Obinutuzumab and Venetoclax. 4 weeks later, her creatinine improved to 1.26 mg/dL and urinalysis was negative for proteinuria or pyuria.
Discussion
This case illustrates the importance of a multidisciplinary collaboration and high degree of suspicion when lymphocytic infiltrates are seen in a kidney biopsy of patients with CLL. The presence of TIN with eosinophils may indicate allergic TIN in this case due to either HCTZ or esomeprazole, but the presence of malignant cells due to CLL is the most likely contributor to the AKI. Mechanistically, AKI secondary to infiltrative disease secondary to CLL is poorly understood with one report hypothesizing tubular microvascular compression and infiltration-associated inflammatory response. Recognition of this phenotype of infiltrative disease in patients with CLL is vital for timely treatment.