CAST-ELISA test--a new diagnostic tool in pollen allergy

We have applied a recently developed method called CAST-ELISA to evaluate the degree of leukocyte stimulation by specific allergen. This method is based on the measurement of sulfidoleukotriene levels in supernatants taken from previously stimulated peripheral blood leukocytes by specific allergen in the presence of interleukin 3.23 patients with pollinosis entered the study. All of them received no medication during 2 weeks before the test. Leukocytes were isolated by dextran sedimentation followed by single centrifugation. After removal of platelet rich plasma the cells were suspended in stimulation buffer and divided into portions incubated with or without specific allergen for 40 minutes at 37 degrees C. After the incubation, the cells were centrifuged and the evaluation of sulfidoleukotrienes in supernatant was performed. The results were expressed in pg/ml after subtraction of the value of spontaneous sulfidoleukotriene production in portions incubated without allergen. The concentration higher than 200 pg/ml of sulfidoleukotrienes above spontaneous production was regarded as a positive result. We have observed a large spectrum of the leukocyte response upon allergen stimulation. In the initial part of our study we established the optimal allergen concentration. The concentration of sulfidoleukotrienes in supernatants ranged from 10 to 5130 pg/ml. The mean sulfidoleukotriene concentration in the whole group was 1671.69. Positive results were observed in 20 persons. In 3 persons the results of allergen stimulation were negative. We conclude that CAST-ELISA is a reliable method to determine the allergic status in persons with pollinosis.