Inter-alpha-trypsin inhibitor heavy chain 1 (ITIH1)

Inter-alpha-trypsin inhibitor heavy chain 1 (ITIH1) is a secreted human plasma glycoprotein that interacts covalently with hyaluronic acid to stabilize the extracellular matrix, regulate tissue remodeling, and modulate inflammatory and immune responses[1][4]. It plays a direct role in preventing tumor metastasis and invasion, operates as an acute phase protein in inflammation, and is associated with various disease processes, including cancer, neuropsychiatric, and degenerative conditions[1][4][3]. ITIH1 is a major structural and functional component of the inter-alpha-trypsin inhibitor complex, composed of multiple chains with distinct roles. ITIH1 is encoded by the *ITIH1* gene and contains a von Willebrand factor A-type domain aiding in ECM binding[1][4][2]. It can form complexes called serum-derived hyaluronan-associated proteins (SHAP-HA), which are particularly noted in conditions such as rheumatoid arthritis (where it may contribute to the inflammatory matrix)[3]. ITIH1’s role in disease is multifaceted, spanning cancer inhibition, inflammatory regulation, and potential diagnostic and prognostic utility, but no approved drugs currently target the molecule directly[4][1].

Other names

Inter-alpha-inhibitor heavy chain 1ITI heavy chain H1ITI-HC1Serum-derived hyaluronan-associated protein (SHAP)Inter-alpha-trypsin inhibitor complex component IIIIGHEP1

Stabilization of the ECM to inhibit tumor growth, regulation of hyaluronic acid metabolism and localization, and anti-inflammatory activity as an acute-phase protein.