Inflammatory response to subcutaneous allergen-specific immunotherapy in patients with bronchial asthma and allergic rhinitis

Abstract

Background: Bronchial asthma (BA) and allergic rhinitis (AR) are chronic inflammatory disorders of the airways. The allergic response is driven by the production of different immunological effector cells cytokines like interleukin-5 (IL-5) and IL-6 among others. Subcutaneous allergen-specific immunotherapy (SCIT) modifies basic immunological mechanisms, reducing IL-5 production. The effect of SCIT on levels of IL-6 is undetermined. Objective: The aim is to study the changes in immunological parameters that follow SCIT in patients suffering from BA and/or AR. Materials and Methods: Twenty-nine patients (18-48 years, mean 25.5 years) diagnosed with BA and/or AR were evaluated for allergic sensitivity using skin prick test (SPT). The patients were started on standardized treatment for BA and AR as per global initiative for asthma and AR and its impact on asthma guidelines, respectively. SCIT was initiated as per the standard Indian guidelines. IL-5 and IL-6 levels were obtained at 0, 3 and 6 months during the course of SCIT and the response was evaluated using Friedman test. Results: Twenty-nine patients; 16 males and 13 females were evaluated and initiated on SCIT. The decreasing order of antigen sensitivity on SPT was mosquito (65.5%), housefly (58.6%), female cockroach (58.6%), male cockroach (48.2%), moth (34.4%) and house dust mite (17.2%). The IL-5 and IL-6 levels, for 0, 3 and 6 months were compared, and it was noted that with an increase in duration of treatment, the levels of inflammatory markers significantly decreases (P = 0.003). On comparison, the inflammatory response between male and female, duration of symptoms and number of positive antigens was not statistically significant. Conclusion: Immunologic changes associated with immunotherapy are complex and allergic patients suffering from asthma, and/or rhinitis showed a significant reduction in levels of inflammatory markers.