Amiloidosis renal hereditaria por depósito de apolipoproteína AI: un reto diagnóstico

Abstract

Hereditary renal amyloidosis is an autosomal dominant condition with considerable overlap with other amyloidosis types. Differential diagnosis is complicated, but is relevant for prognosis and treatment. We describe a patient with nephrotic syndrome and progressive renal failure, who had a mother with renal amiloidosis. Renal biopsy revealed amyloid deposits in glomerular space, with absence of light chains and protein AA. We suspected amyloidosis with fibrinogen A alpha chain deposits, which is the most frequent cause of hereditary amyloidosis in Europe, with a glomerular preferential affectation. However, the genetic study showed a novel mutation in apolipoprotein AI. On reviewing the biopsy of the patient's mother similar glomerular deposits were found, but there were significant deposits in the renal medulla as well, which is typical in APO AI amyloidosis. The diagnosis was confirmed by immunohistochemistry. Apo AI amyloidosis is characterized by slowly progressive renal disease and end-stage renal disease occurs aproximately 3 to 15 years from initial diagnosis. Renal transplantation offers an acceptable graft survival and in these patients with hepatorenal involvement simultaneous liver and kidney transplantation could be considered.

N-terminal mutants of human apolipoprotein A-I: structural perturbations associated to protein misfolding

“…Acidic intracellular milieu was associated to macrophages activation within inflammatory lesions [40]. As mentioned above, the W50R variant is one of the few exceptions in which apoA-I mutants’ deposits are associated to the glomeruli [13][41]. The extracellular matrix (ECM), especially the proteoglycans (PGs) have diverse biologic functions, including binding of growth factors and regulation of collagen fibrillogenesis [42], and their composition is tissue specific [43].…”