Hypersensitivities tryptase release

Immediate hypersensitivity reactions to RCM are associated with histamine release from basophils and mast cells [27], and extensive mast cell activation in vivo associated with clinical symptoms has been demonstrated by Earoche et al. [31]. Patients with hypersensitivity reactions after contrast medium exposure had increased plasma levels of both histamine and tryptase, and levels correlated with severity. Also other investigators have reported high levels of tryptase in connection with severe or fatal reactions [21, 33]. 

An immediate reaction occurs within seconds to minutes, resulting in the rapid release of preformed mediators and newly generated mediators from the arachidonic acid cascade. Mediators of immediate hypersensitivity include histamine, leukotrienes, prostaglandin, tryptase, and kinins. These mediators cause vasodilation, increased vascular permeability, and production of nasal secretions. Histamine produces rhinorrhea, itching, sneezing, and nasal obstruction. 

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