Figure 2
From: Emerging concepts in the diagnosis and treatment of patients with undifferentiated angioedema
Kallikrein-kinin cascade. During an acute HAE attack, reduced activity of C1 esterase inhibitor (C1-INH) results in overactivation of the kallikrein-kinin cascade and subsequent production of bradykinin. Bradykinin is the likely mediator of the vasodilation, edema, and pain that characterize acute HAE attacks. HMWK, high-molecular-weight kininogen; IL, interleukin; MASP, MBP-associated serine protease; MBP, mannose-binding protein; TNF-α, tumor necrosis factor-alpha.