RENAL AMYLOIDOSIS IN CHILDHOOD - AN OVERVIEW OF THE TOPIC WITH 25 YEARS EXPERIENCE

Amyloidosis is a heterogeneous group of diseases characterized by extr acellular accumulation of an eosinophilic, hyalin and proteinaceous ma terial containing mucopolysaccharide substance in various tissues and organs. Knowledge about the chemical structure of amyloid fibril prote ins has led to the recognition of various forms of amyloidosis includi ng Amyloid-A (AA), Amyloid-L (AL), hereditary, senile, dialysis-relate d, localized and cerebral amyloidosis. it is now recognized that all t ypes of amyloid contain amyloid P (AP) component which is derived from the serum amyloid P component, a normal circulating glycoprotein and a member of the pentraxin family. A recent classification proposed by WHO-IUIS (Nomenclature Subcommittee) is based on the chemical nature o f amyloid fibris rather than their clinical and pathologic features. T he kidneys are frequently involved, and renal failure is the major cau se of death. Childhood renal amyloidosis is almost always secondary (r eactive, AA type) and usually associated with chronic inflammatory, in fectious and heredofamilial diseases. In developed countries, rheumato id arthritis is the most common cause of renal amyloidosis, while in d eveloping countries patients with familial Mediterranean fever (FMF) ( untreated) and chronic suppurative infections constitute a large propo rtion of renal amyloidosis cases. No specific therapy is currently ava ilable for amyloidosis. Once renal amyloidosis develops, progress to e nd-stage renal failure is almost inevitable within 2-13 years. The aim of treatment is to give effective supportive therapy and to control t he underlying diseases by colchicine, alkylating agents and appropriat e antibiotics. The prognosis of patients with end-stage renal failure can be improved by maintenance dialysis and renal transplantation. The growing knowledge about the pathogenesis and chemical nature of amylo id fibris may open up further avenues for the discovery of specific th erapeutic modalities against amyloidosis.