Leukocyte Chemotactic Factor 2 (LECT2) Amyloidosis Masquerading as Diabetic Kidney Disease in a Hispanic Patient: A Case Report

Leukocyte chemotactic factor 2 (LECT2) amyloidosis (ALECT2) is a form of renal amyloid deposition that can present with features resembling diabetic kidney disease. We report the case of a woman with long-standing type 2 diabetes mellitus and hypertension who developed progressive renal dysfunction over three years, with her estimated glomerular filtration rate declining from approximately 28 to 10 mL/min/1.73 m² despite stable glycemic control and no identifiable nephrotoxic exposures. Laboratory evaluation revealed minimal albuminuria and unremarkable monoclonal studies, including serum protein electrophoresis, urine protein electrophoresis, and serum free light chain testing. Given the discordance between the degree of proteinuria and the severity of renal function decline, a computed tomography-guided renal biopsy was performed. Histopathologic examination demonstrated Congo red-positive deposits with apple-green birefringence, and immunohistochemical staining confirmed ALECT2. No evidence of systemic amyloid involvement was identified. The patient’s kidney function continued to decline, ultimately progressing to stage 5 chronic kidney disease, and she elected to pursue conservative management. This case illustrates the importance of tissue diagnosis in patients with atypical patterns of chronic kidney disease.