Investigation of the effect of beta-glucan on Th polarisation in type I hypersensitivity reactions

2. ABSTRACT Beta-glucan stimulates and strengthens the immune system. Therefore it is used as a nutritional supplement. In medical product terminology, it is classified as "biological response modifier". This study was undertaken to investigate the effects of beta-glucan, an agent added to classical therapy in type I hypersensitivity reactions, on Th polarization. The study was performed on subjects selected among patients with allergic rhinitis and asthma, and the following groups were formed: Group 1 receiving classical therapy (n=30) Group 2 receiving classical therapy + beta-glucan (n^O) Blood samples were obtained from patients before and 45 days after the commencement of the treatment and evaluated. Lymphocyte subtypes (CD3+, CD4+, CD8+, CD19+, CD23+, CD4+CD26+, CD4+CD30+) ratios were determined by using flow-cytometry. Serum levels of total IgE and cytokines (IL-4, IFN-y) were measured by ELISA. In flow-cytometric analysis; significant changes between pre- and post-treatment values of classical therapy applied Group 1 patients were not observed. In Group 2, post-treatment CD4+, CD4+CD26+ lymphocyte percentages and CD4/CD8 ratio significantly increased while CD23+, CD4+CD30+ cells percentages significantly decreased in comparison to the pre-treatment values. Serum levels of total IgE were significantly reduced in both groups as compared to the pre-treatment values. IL-4 concentrations were significantly decreased in Group 2 as compared to the pre- treatment findings. However, serum IFN-y levels in both groups were significantly increased in comparison to the pre-treatment values. As a result, the inclusion of beta-glucan to the treatment of patients with allergic rhinitis and asthma polarizes the immune response towards Thl. This data presents that the addition of beta-glucan will positively affect the treatment of these diseases. We consider that in order to conclude how long this positive effect continoues, studies involving clinical parameters have to be carried out for longer evaluation periods. Key words: Allergic rhinitis, asthma, beta-glucan, lymphocyte subtypes, cytokine