Evidence of anaphylaxy after alteplase infusion

Background and Purpose-Although alteplase, a recombinant tissue plasminogen activator (tPA), is structurally identical to endogenous tPA and therefore should not induce allergy, single cases of acute hypersensitivity reaction s have been reported. Until now, specific antibodies against alteplase were not detected in blood samples obtained in these patients. Case Description-We report an anaphylactic reaction in a 70-year-old white female who was treated with intravenous alteplase for thrombolysis of acute ischemic stroke 160 minutes after onset of a right-sided hemiparesis. Thir ty minutes after infusion of alteplase had been started, the patient suffer ed acute severe sinus tachycardia and hypotension, followed by cyanosis and loss of consciousness. The alteplase infusion was stopped, and following a ntiallergic therapy, tachycardia and hypotension resolved within 1 hour. Th e hemiparesis remained unaltered, but additional harm resulting from the he modynamic complication was not observed. Serum samples analyzed with a radi oimmunoprecipitation assay were negative for total antibodies to alteplase, but in a subsequent ELISA, both samples were positive for IgE antibodies t o alteplase. Conclusions-The detection of specific IgE antibodies reactive with alteplas e in this patient could provide the first evidence of an anaphylactic-type reaction to alteplase in man. Because previous exposure to alteplase can be excluded, the results suggest that this patient had preexisting antibodies that were cross-reactive with one or more epitopes of alteplase and theref ore precipitated the anaphylactic-type reaction.