Renal Leukocyte Chemotactic Factor 2 (ALECT2) Amyloidosis With Concurrent IgA Nephropathy: A Case Report and Literature Review.

Leukocyte chemotactic factor 2 (ALECT2) amyloidosis is a rare form of renal amyloidosis, typically presenting with chronic kidney disease and variable degrees of proteinuria. Cases of concurrent ALECT2 amyloidosis and IgA nephropathy are exceedingly rare, with limited descriptions of their clinical and pathological features in the literature. Here, we report a 61-year-old Chinese woman who presented with symmetrical lower limb edema and microscopic hematuria, without nephrotic syndrome or significant proteinuria. Renal biopsy revealed diffuse interstitial amyloid deposition and coexisting IgA nephropathy. Laser microdissection combined with mass spectrometry (LMD/MS) confirmed the presence of LECT2 amyloid protein. The patient was diagnosed with ALECT2 amyloidosis with concurrent IgA nephropathy. She was treated with sodium-glucose transport protein 2 (SGLT-2) inhibitors, and her renal function stabilized at a six-month follow-up. Combining immunological techniques and LMD/MS is recommended for the diagnosis of renal ALECT2 amyloidosis.