PLASMA-LEVELS OF PREKALLIKREIN, ALPHA-2-MACROGLOBULIN AND C1-ESTERASEINHIBITOR IN PATIENTS WITH URTICARIAL REACTION TO CONTRAST-MEDIA

Purpose: The plasma levels of prekallikrein, alpha-2-macroglobulin and C1-esterase inhibitor (C1 INH) in patients with previous urticarial r eaction to contrast media (CM) were compared to those of a group of no nreacting age- and sex-matched controls. This study evaluated the valu e of these laboratory variables in predicting acute and delayed urtica rial-type reactions. Material and Methods: The study comprised 44 pati ents (reactors) with acute (n=29) or delayed (n=15) urticaria after ad ministration of CM, and a group of age- and sex-matched controls. Resu lts: In the reactors, the levels of prekallikrein and alpha-2-macroglo bulin were higher (p<0.0001) and the level of C1 INH lower (p<0.0001) than those of the controls. The level of prekallikrein decreased with increasing age (p=0.02) and women had higher values than men (p=0.0054 ). The level of alpha-2-macroglobulin was age-dependent (p=0.006). Con clusion: Although high plasma prekallikrein activity, high plasma alph a-2-macroglobulin activity, and low plasma C1 INH activity are associa ted with urticaria-type reaction to CM, their value in predicting urti carial reaction is limited because prekallikrein is age- and sex-depen dent, and alpha-2-macroglobulin is age-dependent.