[Immunological aspects of laboratory diagnosis of chronic urticaria]

High prevalence of allergic diseases necessitates search for new methods of laboratory diagnosis thereof. We studied the diagnostic significance of the count of cells expressing low-affinity receptors to IgE (CD23+ cells) and compared this test with skin tests with non-infectious allergens and measurement of total serum IgE. 104 patients with various forms of chronic relapsing urticaria were examined. The count of CD23+ cells was markedly increased in atopic urticaria. The increase in the count of these cells and correlation with the results of skin test were less expressed in infectious allergic urticaria. In other forms of chronic urticaria characterized by negative results of skin tests the count of CD23+ cells was normal. The level of total serum IgE was low virtually in all patients. Hence, the count of cells carrying low-affinity receptors to IgE is highly informative, detecting IgE-mediated reactions in the patients, though this parameter does not allow identification of the allergen. This test can be used in complex with other methods of allergodiagnosis, particularly in cases when skin tests are for this or that reason impossible.