In Vivo Anti-Inflammatory Effect of H1 Antihistamines in Allergic Rhinitis: A Randomized Clinical Trial.

Background: Allergic rhinitis is characterized by a chronic inflammation of nasal mucosa and represents a risk factor for asthma occurrence. H1 antihistamines reduce the symptoms of rhinitis, but some compounds may have anti-inflammatory properties. Aims: We evaluated the plasma level of some cytokines in patients with persistent allergic rhinitis (PAR) and their evolution after a 4-week treatment with H1 antihistamines, as well as the risk of asthma after 1.5 years. Study Design: Randomized clinical trial. Methods: Eighty-five patients with PAR and 30 healthy volunteers were included in the study. The patients with PAR were randomly divided into 2 groups: 41 patients treated with 5 mg/day desloratadine and 44 patients under 5 mg/day levocetirizine for 4 weeks. The clinical and biological evaluations were performed before and after treatment and included rhinitis symptoms and total symptoms score, type of sensitization, and plasmatic levels of total IgE, IL-1 beta, IL-6, IL-8 and TNF-alpha. Results: IL-8 and TNF-alpha were significantly increased in patients with PAR compared to healthy volunteers (5.85 vs 3.12, p<0.001 and 2.32 vs 1.06, p<0.001, respectively). Both H1 antihistamines reduce all symptoms of allergic rhinitis, including nasal congestion and the plasmatic level of IL-1 beta, IL-6, IL-8 and TNF-alpha, after 4 weeks of treatment. The reduction of cytokine levels was not influenced by patients' age, sex, duration or severity of rhinitis, or type of sensitization. Levocetirizine has a superior effect compared to desloratadine in reducing the rhinitis symptoms and cytokines' level. Twenty eight (32.9%) of the patients presented asthma symptoms after 1.5 years. The occurrence of asthma was influenced by house dust sensitization (OR-14.6; CI 95% 1.8-116.3; p=0.01), but baseline values of cytokines were not predictive factors for its appearance. Conclusion: Levocetirizine and desloratadine as a prolonged therapy reduce plasmatic levels of some pro-inflammatory cytokines in patients with PAR. Levocetirizine has a better effect on decreasing the symptoms and plasmatic levels of IL-1 beta and IL-8. (ClinicalTrials. gov Identifier: NCT02507635)