[Allergic reactions in treatment with L-asparaginase. Significance of specific IgE antibodies].

: The formation of specific IgE antibodies to L-Asp was studied in 27 children with ALL. Increased titers of specific IgE antibodies were significantly more frequent (p less than 0.001) prior to L-Asp infusions followed by allergic reactions than in those without reactions. After passive sensitization of basophile granulocytes of a healthy volunteer using patient's serum with the highest titers of specific IgE antibodies to L-Asp a significant release of histamine was observed after exposure of cells to L-Asp. In 1 of 8 patients with allergic reactions titers of specific IgE antibodies were elevated, while there was not detectable activation of the complement system. In conclusion, elevated titers of specific IgE antibodies to L-Asp are frequently detectable prior to L-Asp infusions which are associated with allergic reactions. In addition to activation of the classical complement pathway specific IgE antibodies and mediator release from mast cells may contribute to clinical symptoms. In a small number of patients this mechanism alone may be responsible for the allergic reaction.