Usefulness of UniCAP‐Tryptase fluoroimmunoassay in the diagnosis of anaphylaxis

Abstract

Serum tryptase level measured by RIA is the main in vitro tool to confirm the diagnosis of anaphylaxis. Serum tryptase levels were determined by UniCAP-Tryptase fluoroimmunoassay (Pharmacia & Upjohn, Uppsala, Sweden), in 30 consecutive patients who presented at the emergency room with a clinical allergic reaction of less than 6-h duration to assess the value of this method in the diagnosis of anaphylaxis. Anaphylaxis was established by clinical criteria and by immunoallergic study. Baseline tryptase levels were determined 1 month later in 21 patients. The receiver operating curve (ROC) was used to establish the best cutoff point of tryptase levels to confirm the diagnosis of anaphylaxis. Seventeen patients were diagnosed with anaphylaxis. In this group, tryptase levels were higher than in the nonanaphylaxis group, composed mostly of patients with urticaria or angioedema (P8.23 ng/ml by UniCAP-Tryptase fluoroimmunoassay identify anaphylaxis in patients with symptoms of less than 6-h duration. The usefulness of this determination is higher if baseline tryptase levels are available.