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Kidney Week

Abstract: SA-PO247

Proximal Tubulopathy Secondary to Chronic Lymphocytic Leukemia After COVID-19 Infection

Session Information

Category: Onconephrology

  • 1700 Onconephrology

Authors

  • Paredes, William Mauricio, SBH Health System, Bronx, New York, United States
  • Flores Chang, Marjorie Mailing, SBH Health System, Bronx, New York, United States
  • Flores Chang, Bessy Suyin, SBH Health System, Bronx, New York, United States
Introduction

Light chain proximal tubulopathy is a rare kidney disorder that occurs when free light chains are filtered by the kidneys and then accumulate in the tubules, leading to kidney damage and dysfunction. This condition is often associated with multiple myeloma. While chronic lymphocytic leukemia (CLL) is not typically associated with light chain proximal tubulopathy, there have been rare cases reported in the medical literature. However, to our knowledge, no reports have been found of developing both conditions after a COVID-19 infection.

Case Description

A 60-year-old male with pre-DM presented were decreased appetite, fatigue, and dizziness his physical examination was unremarkable. Initial workup was significant for COVID-19 infection, serum creatinine of 3.2 mg/dL, GFR: 20 cc/min, however, was discharged for outpatient follow-up. Urinalysis showed proteinuria and hematuria (33 RBC per hpf), serum creatinine stable to 3.3 mg/dL, GFR: 20 cc/min, spot protein to creatinine ratio of 1.8 g, ANCA profile, hepatitis B and C serologies were non-reactive. Complement C3 slightly decreased 73 mg/dL (82-167mg/dL), serum-free light chains ratio of 14.6. Prior serum creatinine was 0.9 mg/ dl ~4 years prior. Kidney biopsy demonstrated focal endocapillary and extra capillary proliferative glomerulonephritis with apparent lgG1 kappa deposits (light chain proximal tubulopathy), supporting the diagnosis of monoclonal gammopathy of renal significance (MGRS). Hemato-oncology evaluation noted worsening weight loss since the COVID-19 infection and left supraclavicular and bilateral inguinal lymphadenopathy with palpable hepatosplenomegaly. He underwent a bone marrow biopsy showing atypical lymphocytosis, trisomy 12 in 45.5% of cells, and flow cytometry findings of the clonal B-cell population (60-65% of total), immunophenotypically represents (CLL). Treatment was started with Venetoclax, febuxostat, and obinutuzumab. His serum creatinine stabilized at 2.4 mg/dL with a GFR of 28 cc/min.

Discussion

Chronic lymphocytic leukemia rarely can present with deposition of free light chains in the kidneys leading to Light chain proximal tubulopathy. We present a case of a patient who had this presentation after having a COVID-19 infection. To our knowledge, there have been no reported cases of MGRS or chronic lymphocytic leukemia after a COVID-19 infection.