Comparison of two specific allergen screening tests in different patient groups.
ABSTRACT UniCAP and multiple-antigen simultaneous test (MAST) are among the widely used specific allergen tests. The Phadiatop and Fx5 are the multi-allergen UniCAP screening tests for inhalant allergens and common food allergens, respectively. We compared the differences between Phadiatop-Fx5 and MAST as screening allergen tests to clarify the optimal tests for different groups of allergic patients. Serum samples of 224 consecutive allergic patients were tested with Phadiatop, Fx5 and MAST. Results of these allergen tests were compared and analyzed in subgroups categorized by age, serum IgE levels and the clinical departments where the patients were treated. We found that among the 224 patients, 155 patients (69.2%) tested positive with Phadiatop while 137 (61.1%) tested positive with MAST for inhalant allergens. Twenty patients were Phadiatop(+)/MAST(-), while only 2 were Phadiatop(-)/MAST(+). There were 57 patients (25.4%) who tested positive with Fx5, while 32 (14.3%) tested positive with MAST for food allergens. Thirty-eight patients were Fx5(+)/MAST(-), while 13 were Fx5(-)/MAST(+). The disagreement between these two tests was more apparent in food allergen tests than in inhalant allergen tests. Most cases of disagreement occurred in younger age groups and in the patient group with IgE > 500 IU/ml. These results suggested that UniCAP allergen screening tests might be more effective in certain patient groups as screening tests.