A rare case of ALECT-2-amyloidosis with kidney damage

A clinical case of the rare kidney disease ALECT-2-amyloidosis, which is the first description of this pathology in the Russian Federation, is presented. The data of patient D., 72 years old, who sought medical help in December 2024 with complaints of severe general weakness, shortness of breath, lack of appetite, and widespread edema are presented. There were signs of nephrotic syndrome. A morphological examination of the kidney biopsy revealed a pattern of amyloidosis with a predominant lesion of the arterial walls, arterioles, and glomeruli. At the same time, the deposits were identified as not belonging to the AA-type and AL-type using immunofluorescence analysis using appropriate antibodies. Proteomic analysis of urine revealed an increase in the level of leukocyte chemotoxic factor 2 (LECT2), which indicates its relation to amyloidogenesis. At the same time, in the cases described in the literature, as a rule, there was no increase in its plasma level, which was also not recorded during a proteomic blood test in our patient. Thus, amyloidosis with kidney damage was caused in the patient by LECT2 and was identified as LECT2-amyloidosis.