[Immunological and serological laboratory tests: transthyretin].

Transthyretin (TTR) is a beta-sheet rich protein whose plasma half life is 1.9 days. It behaves as a tetramer and binds to retinol binding protein (RBP) and thyroxin in plasma. Since TTR is a tryptophan-rich-protein, the protein is used as a useful marker protein for nutrition supporting team (NST). However, TTR is also an anti-acute phase protein, and the concentration is influenced by various conditions, such as inflammation and infection, Mutated forms of TTR are the precursor protein of familial amyloidotic polyneuropathy (FAP). Since plasma TTR is predominantly synthesized by the liver, liver transplantation has been performed as an effective therapy for FAP. Recent research revealed that TTR plays important roles in various central nervous system disorders, such as Alzheimer disease, depression, and lead intoxication. To elucidate the pathogenesis of those disorders, an accurate measurement of TTR concentrations in plasma and cerebrospinal fluids is of vital importance.