Hereditary amyloidosis with renal damage as a clinical problem: a case report

This article describes a clinical case of a 28-year-old woman with a long history of chronic anemia (observed since 2017), hepatosplenomegaly, mesenteric lymphadenopathy, and proteinuria, initially diagnosed as chronic tubulointerstitial nephritis with CKD Stage 2. In April 2024, the patient was hospitalized to clarify the diagnosis: a series of laboratory and instrumental studies were conducted, including a nephrobiopsy using standard methods, which did not reveal amyloid deposits. In November 2024, based on a re-evaluation of previously obtained nephrobiopsies using additional staining methods (Congo red staining, immunofluorescence, and immunohistochemistry), massive amyloid deposits were detected, predominantly consisting of lysozyme, which allowed establishing the final diagnosis — genetically determined lysozyme amyloidosis of the kidneys. This case underscores the importance of dynamic observation and repeated morphological analysis in cases of clinical discordance and the use of specialized research methods to clarify rare variants of amyloidosis.