Medullary amyloidosis associated with apolipoprotein A-IV deposition Academic Article uri icon

Overview

MeSH Major

  • Amyloidosis
  • Apolipoproteins A
  • Kidney Diseases
  • Kidney Medulla

abstract

  • Amyloidosis is caused by extracellular deposition of proteins in an insoluble manner within tissues. In hereditary forms of amyloidosis, transthyretin, fibrinogen A-α, lysozyme, gelsolin, apolipoprotein A-I, and A-II accumulate in the tissue plaques. Here we describe a 52-year-old man with no family history of renal disease who presented with increased urinary frequency, gradual loss of renal function but no significant proteinuria. Renal biopsy found large amounts of amyloid restricted to the medulla with no involvement of glomeruli or vessels. Immunohistochemical analysis for transthyretin or serum amyloid A and tests for an underlying monoclonal gammopathy were negative. Although initially suspected to be amyloid light chain amyloidosis, laser microdissection and mass spectrometry showed that the amyloid was composed of large amounts of apolipoprotein A-IV. This was based on mass spectrometry studies that showed 100, 96, and 73 spectra in three microdissected samples that matched to apolipoprotein A-IV with 100% probability. DNA analyses detected three sequence variants representing common polymorphisms of the apolipoprotein A-IV gene. Thus, in this case, apolipoprotein A-IV deposition and renal involvement appear to be restricted to the medulla. A high degree of suspicion is required for the diagnosis of apolipoprotein A-IV amyloidosis as it may be missed if a renal biopsy consists only of cortex.

publication date

  • January 2, 2012

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1038/ki.2011.316

PubMed ID

  • 21900878

Additional Document Info

start page

  • 201

end page

  • 6

volume

  • 81

number

  • 2