[Evaluation of allergen-specific IgE antibody and total IgE with a new IgE detection system named FAST: fluorescence allergosorbent test].

The measurement of IgE antibodies and total IgE was performed with FAST (fluorescene allergosrobent test) system using 171 serum samples obtained from normal donors and 789 serum samples obtained from patients with various allergic diseases. These were collected by departments of internal medicine, pediatrics, otorhinolaryngology and dermatology at 17 institutes in Japan. In addition to a comparative study with RAST, skin tests and provocation tests were also performed to establish a clinical diagnosis. Simultaneous measurements were made and an excellent correlation with RAST was observed with a concordance rate of 85.7% and correlation coefficient of 0.848. The specificity determined in the normal serum samples was 95.5% by RAST and 93.1% by FAST. The sensitivity determined in the samples, of which etiological allergens were identified clinically, was 82.3% by RAST and 85.3% by FAST. Among them, the sensitivity of skin test and provocation test were 92.4% and 94.7%, respectively. The concordance rate with clinical diagnosis was as high as 89.7% for both RAST and FAST. The normal upper limit of total IgE by cumulative 95% value was calculated to be 250 IU/ml for adult subjects. These results indicated the clinical usefulness of the FAST system in evaluating IgE antibodies and total IgE.