Search

Urticaria and angioedema are common disorders that affect approximately 1/5 of the population at some stage in their lives. Although the clinical diagnosis of this disorder is made without difficulty, its etiology and pathogenesis remain obscure. Extensive clinical studies and the application of different laboratory techniques seldom manage to detect the etiology of chronic urticaria or determine its supposed pathogenic mechanism. Thus, a large number of causal agents have been held responsible for the symptoms of chronic urticaria and/or chronic urticaria and angioedema and for the variety of immunologic and nonimmunologic factors involved in its pathogenesis. The controversial laboratory findings in this type of patients prompted us to undertake this study on 48 subjects with chronic urticaria and/or angioedema. We studied the levels of serum immunoglobulins (IgG, IgA, IgM and IgE), the haemolytic activity of the complement (CH50), the levels of the complement components (C1 inhibitor, C3 and C4), the possible presence of circulating immune complexes and the percentages of the T lymphoid subpopulations (using OKT3, OKT4 and OKT8 markers) and the B population. The results obtained showed an alteration of the complement (CH50) and of some of its components (C3 and C4) as well as of the cytotoxic/suppressor lymphocyte subpopulation (OKT8).

It is generally accepted that the allergic reaction depends on the levels of specific IgE, on the concentration of blocking antibodies and on the capacity of the basophils to release mediators. The fact that in the histamine release test (HRT) all of the elements intervening in an allergic reaction (antigens, IgE, basophils and mononuclear cells of a lymphoid origin) have been found, has led some authors to consider it as the most suitable method of "in vitro" diagnosis. This is a reflection of what biologically occurs "in vivo". Furthermore, the HRT can be used as a control parameter following immunotherapy, permitting us not only to quantify the level of blocking antibodies but also to study the possible presence of a control mechanism of histamine release. Accordingly, in a group of 50 patients with extrinsic asthma we carried out a HRT, skin tests (prick test) and Rast with house dust, Dermatophagoides pteronyssinus and Dermatophagoides farinae. In another group comprising 74 subjects with extrinsic allergic asthma (45 with perennial allergic rhinitis) we performed a HRT with aeroallergens. This group was subjected to immunotherapy (dust with mites) for a year. Following this treatment another HRT was carried out with house dust, Dermatophagoides pteronyssinus and Dermatophagoides farinae. With regard to our results in the first group we obtained 80% agreement in the HRT/prick test/Rast for house dust and Dermatophagoides pteronyssinus and 78% agreement for Dermatophagoides farinae.(ABSTRACT TRUNCATED AT 250 WORDS)