Abstract
Background
Plasma transthyretin (TTR) is routinely quantified in clinical laboratories, yet the structural heterogeneity of circulating TTR and its potential impact on laboratory measurement remain poorly characterized. In transthyretin amyloid cardiomyopathy (ATTR-CM), information on native circulating TTR forms is limited.
Methods
An analytically optimized native polyacrylamide gel electrophoresis (PAGE) followed by Western blotting for the characterization of TTR and retinol-binding protein 4 (RBP4) in human plasma was developed. Samples from 71 ATTR-CM patients and 71 age- and sex-matched controls were analyzed. Electrophoretic bands were characterized by data-independent acquisition mass spectrometry, and total TTR was measured by routine nephelometric assay.