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Background: Approximately 35-40% of patients with chronic urticaria have an IgG autoantibody to the IgE receptor which can activate basophils and mast cells so that they release histamine. In this study we assessed the cytokine profile present in chronic urticaria sera, and then measured cytokine and leukotriene release from basophils and mast cells upon incubation with chronic urticaria sera. Finally we assessed cytokine expression at the single-cell level and characterized the T cell subpopulations involved in their production. We chose IL-4 as representative of Th2 lymphocytes and IFN-gamma for Th1 lymphocytes., Methods: We analyzed IL-4, IL-5 and IFN-gamma in 60 chronic urticaria sera versus 51 controls. Sera were incubated with purified human basophils and cutaneous mast cells and the release of histamine, IL-4 and leukotrienes (C(4), D(4), E(4)) was quantitated. Immunoblotting was performed to identify IgG antibody to FcepsilonRIalpha, alpha subunit. We measured intracellular cytokine production in peripheral blood mononuclear cells of 17 chronic urticaria patients compared to 50 healthy controls., Results: We found higher IL-4 levels (p = 0.028) in the sera of chronic urticaria patients (1.03 pg/ml) versus healthy donors (0.20 pg/ml) but no difference between urticaria sera and atopic control sera (0.52 pg/ml). We did not detect IFN-gamma or IL-5 in any serum. However, sera that activated basophils so that they released histamine also produced leukotriene and IL-4, and leukotriene production by cutaneous mast cells and basophils was closely correlated. However, there was no correlation between immunoblotting and the functional ability to induce either histamine or IL-4. After stimulating with PMA-ionomycin we found significant differences in CD4+ lymphocyte production of IL-4 and IFN-gamma with no differences in CD8+ lymphocyte production of either cytokine., Conclusion: Our data support the presence of basophil and mast cell activators in the sera of patients with chronic urticaria which can lead to the production of leukotrienes and IL-4 in addition to the histamine. IL-4 levels are similar to those seen in atopic subjects. We found that CD4+ T cells from patients with chronic urticaria are activated and tend to produce higher cytokine levels than CD4+ T cells from healthy controls. There were no differences when cytokine production by CD8+ lymphocytes was similarly assessed. These results are consistent with the histology found in biopsies of chronic urticaria lesions, where a CD4+-predominant infiltrate is found with cytokine production suggesting either a Th0 response or a mixture of Th1 and Th2 lymphocytes., (Copyright 2002 S. Karger AG, Basel)

We have demonstrated previously mast cell histamine release upon incubation with chronic urticaria (CU) sera, presumably by degranulation. To explore total and mature tryptase in order to assess whether any increase in total tryptase levels is due in part to mast cell degranulation or to mast cell burden. We also wanted to explore differences between the autoimmune groups called idiopathic (serum unable to activate basophils), and to correlate total and mature tryptase levels with different urticaria features. We measured total and mature tryptase serum levels in 81 CU patients, 16 atopic donors and 21 healthy control sera. We assessed autoimmunity by measuring the CD63 expression in normal basophil donors upon incubation with CU sera. We found significantly higher levels of total tryptase in the sera of CU patients (6.6 ±4.1 μg/L) than in sera from healthy non-atopic subjects (4.4 ±2.8 μg/L) and from atopic subjects (4.5 ±1.7 μg/L). Mature tryptase levels were undetectable (<1 ng/mL). Total tryptase levels in the autoimmune urticaria group were significantly higher (9.8 ±5.4 μg/L) than the idiopathic urticaria group (4.4 ±2.2 μg/L). A significant difference in total tryptase was found between symptomatic patients (7.3 ±4.1 μg/L) compared with asymptomatic ones (5.7 ±4.1 μg/L) at the time of venesection. No difference was found in mature tryptase levels either. Total elevated tryptase levels are not accompanied by an elevated mature tryptase levels, as might be expected if the serum levels reflected mast cell degranulation. Cite this as: M. Ferrer, J. M. Nuñez-Córdoba, E. Luquin, C. E. Grattan, J. M. De la Borbolla, M. L. Sanz, L. B. Schwartz, Clinical & Experimental Allergy, 2010 (40) 1760-1766. [ABSTRACT FROM AUTHOR]

Although it has been shown that basophils from patients with chronic ordinary urticaria (CU) are less responsive than normal basophils when stimulated with anti-IgE, very few studies have examined the response of those cells to alternative stimuli.To compare releasability between basophils from healthy donors and patients with CU.We examined the response of IL-3-treated basophils from healthy donors, atopic controls and CU patients to anti-IgE, monocyte chemoattractant protein-1 (MCP-1), bradykinin, C5a and to sera obtained from other urticaria patients and normal controls. We also compared the response of basophils from CU patients whose sera activate normal basophils (autoimmune CU) from those who do not (idiopathic CU).Basophils of CU patients release significantly less histamine than basophils of normal controls when stimulated with anti-IgE, and to a lesser degree with C5a. No differences were observed when basophils from patients were incubated with Bradykinin or MCP-1. However, when basophils of CU patients were incubated with sera from other CU patients or even normal sera, we found significantly higher histamine release compared with the response of basophils from normal donors. We could not distinguish responsiveness of basophils of patients with chronic autoimmune urticaria from patients with chronic idiopathic urticaria.Basophils of patients with chronic idiopathic urticaria and chronic autoimmune urticaria are hypo-responsive to anti-IgE and C5a, normally responsive to MCP-1 or bradykinin, and hyper-responsive to serum. The serum factor to which a response has not yet been identified; however, basophils of patients with chronic urticaria, in general, appear to have abnormal regulation of signaling pathways. [ABSTRACT FROM AUTHOR]