The effect of H 1-antihistamines on allergic inflammation in patients with allergic rhinitis

mites, exposure to a new type of allergens and chronic stress (Mösges & Klimek 2007). Allergic inflammation is the key to understanding these diseases. The relationship between asthma and AR is not completely understood. This concept could be explained by the presence of inflammatory cells and mediators from the upper airway in the lower one, acting as triggering factors in bronchial inflammation (Canonica & Complati 2009). We found similar inflammatory cells in both asthma and rhinitis, such as eosinophils, mast cells, T lymphocytes and monocytes, and the same proinflammatory mediators (histamine, cytokines like IL-4, IL-5, IL-13, GM-CSF, eotaxine and adhesion molecules) (Bousquet et al. 2008, Bousquet et al. 2003, Leynaert et al. 2004). The amplitude of allergic inflammation is not necessarily identical in nasal and bronchial mucosa, but eosinophilic airway inflammation is present in the nasal mucosa of patients with asthma, even if they don’t have nasal symptoms (Bousquet et al. 2008, Leynaert et al. 2004). One of the non-invasive possibilities to evaluate lower airway inflammation is the measurement of fractional nitric oxide in Introduction Allergic rhinitis (AR) is the most frequent allergic disease, which affects 20-30% of the world’s population (Bousquet et al. 2008, Bousquet et al. 2010). AR and bronchial asthma are both clinical manifestations of atopy. The relationship between AR and asthma has become notorious for several years. Asthma and AR are now considered as two expression of the same pathological process, presented as „united airways disease” (Bousquet et al. 2003, Bousquet et al. 2010). Thus, these two diseases often coexist and therapeutic guidelines recommend performing a complete evaluation in patients with AR in order to diagnose the possible association with asthma. AR is now considered a risk factor for asthma development; approximately 30% of patients with persistent allergic rhinitis (PAR) may develop asthma in time (Leynaert et al. 2004). Nowadays, a number of factors influence the severity and persistence of AR symptoms, which may increase the risk of developing asthma. These factors are related to changes in lifestyle and urbanization, increased air pollution, spending more time indoors, which implies a prolonged exposure to house dust Abstract. Introduction: Allergic rhinitis (AR) is the most frequent allergic disease and a risk factor for asthma occurrence. The relationship between AR and asthma is well known but not completely understood. This relationship could be explained by the presence of inflammatory cells from the upper airway in the lower one. The aim of this study is to evaluate the presence of minimal persistent inflammation in the lungs using fractional exhaled nitric oxide (FeNO) in patients with AR and correlate it with the severity of the disease. The second aim is to evaluate the effect of AH1 on this subclinical inflammation in AR patients. Material and method: The study included 79 patients with persistent allergic rhinitis. Clinical evaluation was done based on the presence and severity of AR symptoms and quality of life was measured using the visual analogue scale (VAS). Biological evaluation included the absolute eosinophil count. FeNO was measured using NIOXMINO®. After the initial evaluation, patients were randomly divided into two groups, 39 patients were treated with levocetirizine 5 mg/day and 40 patients received desloratadine 5 mg/day. Patient assessment was performed at baseline and after one month of treatment with H1-antihistamines. Results: Fiftysix patients (70.9%) had moderate-severe AR, with a total symptom score (TSS) of over 6. Sleep quality was impaired; VAS was negatively correlated with TSS (R=-0.458, p=0.000). Patients with AR had elevated levels of peripheral eosinophils (median value 5.11) and FeNO (median value 27). There was no correlation between basal level of eosinophils and basal FeNO (R=0.052, p=0.648). AH1 improved TSS (median values 8 vs. 0, p<0.001) and VAS (median values 4.6 vs. 9.8, p<0.001), reduced peripheral eosinophil (median values 5.11 vs. 4.10, p<0.001) and FeNO (median values 27 vs. 16, p<0.001) count after 1 month of treatment. Desloratadine was more efficient in the reduction of FeNO levels (38 vs. 14) compared to levocetirizine (23 vs. 17.5) (p=0.05). Conclusions: Patients with persistent AR have elevated peripheral eosinophil and FeNO levels. Levocetirizine and desloratadine improve symptoms and increase quality of life in patients with persistent AR. Levocetirizine and desloratadine as a continuous therapy determine a reduction of FeNO levels, limiting the progression of allergic inflammation to the lower airway.