Allergic Reaction to Alteplase Dwell in Chronic Automated Red Cell Exchange Patient

Allergic reactions to intravenous, alteplase have been reported, usually in doses utilized for thrombolysis. Alteplase is also widely used for clearance of occluded catheter lumens, but allergic reactions have not been reported for this route of administration. A 14-year-old patient with sickle cell disease presented with an occluded apheresis port. During alteplase dwell for port occlusion, he developed an initial reaction concerning for anaphylaxis prior to automated red cell exchange, resulting in hospitalization. Findings included angioedema to the tongue and lip as well as urticaria on his abdomen and over a previous port scar, which became warm and firm. Of note, the patient also has a history of severe atopy, uncontrolled eczema, asthma, allergic rhinitis, and elevated eosinophils. The patient was referred to allergy and a skin test to alteplase was negative. The patient underwent an alteplase challenge through his catheter where he experienced anaphylaxis. Despite appropriate treatment, he again required inpatient admission. Post reaction serum tryptase level was not elevated. A clear temporal relationship to alteplase exposure and subsequent allergic reaction was documented in this case. To our knowledge, this is the first reported case of allergic reaction to intraluminal alteplase used for clearance of an occluded apheresis port. The non-elevated tryptase level suggests a non-IgE mediated reaction. Allergic reaction to alteplase dwell for clearance of occluded lumens can occur and is an entity apheresis providers should be aware of. Additionally, traditional skin testing may not be entirely predictive of safety upon rechallenge.