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Updated: Mar 15, 2026
Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis
Published on: June 9, 2018
Apolipoprotein A-IV Cardiac Amyloidosis Diagnosed by Mass Spectrometry-Based Proteomic Analysis
Yu Masutani1, Kenji Onoue2, Tsunenari Soeda3
1Department of Internal Medicine, Nara General Medical Center, Nara, Japan; Department of Cardiovascular Medicine, Nara Medical University, Nara, Japan.
Background:
Apolipoprotein A-IV amyloidosis (AApoA-Ⅳ) is a rare subtype of cardiac amyloidosis (CA) and is often overlooked because of its clinical similarity to transthyretin (ATTR) CA.
Case Summary:
An 82-year-old man presented with heart failure with preserved ejection fraction. His clinical features, including grade 1 uptake on 99mTc-pyrophosphate scintigraphy, closely mimicked ATTR CA. Histologic examination revealed intracellular Congo red-positive amyloid deposits and characteristic electron microscopic findings. Mass spectrometry-based proteomic analysis confirmed the diagnosis of AApoA-IV CA.
Discussion:
Although the pathologic significance of the unique histologic features remains unclear, they may represent distinguishing characteristics of AApoA-IV amyloidosis.
Take-Home Messages:
AApoA-IV CA typically presents with elderly-onset heart failure with preserved ejection fraction and may show positive uptake on bone scintigraphy. Differentiation from ATTR CA is possible based on characteristic histopathologic findings and mass spectrometry-based proteomic analysis.
