ITIH3

ITIH3 (inter-alpha-trypsin inhibitor heavy chain 3) is a liver-secreted plasma glycoprotein of the inter-alpha-trypsin inhibitor (ITI) family. Heavy chains such as ITIH3 are covalently attached, via chondroitin sulfate, to bikunin to form the circulating ITI complexes that stabilize hyaluronan-rich extracellular matrix and restrain inflammatory proteolysis at sites of tissue injury. ITIH3 contains an N-terminal VIT domain characteristic of the family and behaves as an acute-phase reactant. Genetic variants near ITIH3 have been associated with rheumatoid arthritis susceptibility, and altered serum levels are reported in cancers and inflammatory diseases, supporting its biomarker candidacy. Recombinant ITIH3 aids studies of ITI assembly and inflammation.