Topical thrombin-induced IgE-mediated anaphylaxis: RAST analysis and skin test studies.

Bovine topical thrombin (BTT) is a heterologous plasma thrombin concentrate that has been frequently used for the hemostasis since the 1940s. Recently, three patients in Japan went into shock after the topical application of BTT at lesion sites, and two of these patients had received BTT repeatedly. The clinical symptoms and the increased anti-BTT percent RAST counts suggest that these reactions were shock mediated by anti-BTT IgE antibodies. The RAST-inhibition analysis suggested that the antigenic substance(s) were bovine-specific moiety(ies) mainly involved in the contaminant rather than bovine thrombin itself. The skin tests were studied to predict such allergic reactions. The intracutaneous test provoked nonspecific reactions even at the low concentrations of BTT. The prospective study on the predictive value of the prick test with 1000 U/ml (1 mg/ml) of BTT in 192 patients suggested that it is useful to detect highly sensitive patients. In addition, the increased levels of anti-BTT IgE antibodies in patients 1 month after the single administration of BTT suggested the immunogenicity of the topical application of BTT.