Many pathological processes, including those causing allergies and autoimmune diseases, are associated with the presence of specialized subsets of T helper cells (TH1 and TH2) at the site of inflammation. The diversity of TH1 and TH2 function is not predetermined but depends on signals that drive the cells towards either subset. Histamine, released from effector cells (mast cells and basophils) during inflammatory reactions can influence immune response. Here we report that histamine enhances TH1-type responses by triggering the histamine receptor type 1 (H1R), whereas both TH1- and TH2-type responses are negatively regulated by H2R through the activation of different biochemical intracellular signals. In mice, deletion of H1R results in suppression of interferon (IFN)-gamma and dominant secretion of TH2 cytokines (interleukin (IL)-4 and IL-13). Mutant mice lacking H2R showed upregulation of both TH1 and TH2 cytokines. Relevant to T-cell cytokine profiles, mice lacking H1R displayed increased specific antibody response with increased immunoglobulin-epsilon (IgE) and IgG1, IgG2b and IgG3 compared with mice lacking H2R. These findings account for an important regulatory mechanism in the control of inflammatory functions through effector-cell-derived histamine.

Histamine, which acts via G protein-coupled receptors, is an important mediator of immediate hypersensitivity and is also able to influence the nature of T cell responses. We demonstrated that TH1 and Th2 cells express distinct surface histamine receptor patterns and that Th1-type responses are enhanced by histamine, whereas Th2-type responses are negatively regulated, due to different intracellular signals generated by histamine stimulation. These findings account for negative feedback regulation in a wide variety of pathologies.

Tracheobronchial involvement in Crohn's disease is rare, usually associated with symptoms of tracheobronchitis, and typically responds well to steroids. The authors report a case of a 29-yr old patient with Crohn's disease, who presented with dyspnoea, fever, and a productive cough. Computed tomography of the chest revealed extensive nodular tracheobronchial stenosis, that was accompanied by severe mucosal inflammation at bronchoscopy. High-dose oral steroids diminished the mucosal inflammation, but had limited efficacy on the underlying tracheobronchial stenosis. It is speculated that this relative ineffectiveness of steroids may be due to the persistence of the untreated inflammatory process.

Background. Males and females exhibit different susceptibility to allergic diseases. Objectives. The aim of the study was to evaluate gender-related differences in the prevalence of allergic diseases in Poland. Material and Methods. To evaluate this problem, data from the Polish Multicenter Study of the Epidemiology of Allergic Diseases (PMSEAD) was analyzed. There were assessed 16,238 individuals, aged 3 to 80 years, among them 12,970 adults and 3,268 children. Results. In adults the prevalence of asthma was 5.4%, seasonal allergic rhinitis 8.5%, persistent allergic rhinitis 3.0%, atopic dermatitis 1.6%, contact dermatitis 2.0%, and drug allergy 8.6%. In children asthma was diagnosed in 8.6% of the individuals assessed, seasonal allergic rhinitis in 8.6%, persistent allergic rhinitis in 2.1%, atopic dermatitis in 4.7%, contact dermatitis in 1.1% and drug allergy in 8.9%. Among the children in the sample, significantly higher prevalence rates were found in boys than in girls for asthma (10.9% vs. 6.3%; OR = 1.81; p < 0.001), seasonal allergic rhinitis (9.8% vs 7.4%; OR = 1.37, p = 0.018) and persistent allergic rhinitis (2.6% vs. 1.5%; OR = 1.74, p = 0.029). When comparing the differences by gender among adults, there was a lower proportion of male than female subjects suffering from asthma (4.9% vs. 5.8%; OR = 0.83, p = 0.018), seasonal allergic rhinitis (7.6% vs. 9.3%; OR = 0.81, p = 0.001), atopic dermatitis (1.1% vs. 2.0%; OR = 0.53, p < 0.001), contact dermatitis (1.1% vs. 2.8%; OR = 0.39; p < 0.001) and drug allergy (5.1% vs. 11.6%; OR = 0.41, p < 0.001). Conclusions. The opposite susceptibility to allergic diseases among children and adults may indicate that sex hormones play an important role in this phenomenon (Adv Clin Exp Med 2014, 23, 5, 757-762).

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