Allergen-Specific Immunotherapy In Combination With Vitamin D In Patients With Seasonal Allergic Rhinitis

Introduction — Currently, over 500 million people suffer from allergic rhinitis worldwide. For many decades, allergen-specific immunotherapy (ASIT) was the only effective treatment for seasonal allergic rhinitis. The development of molecular allergy diagnostics via ISAC technology allows identifying true and cross-reactive allergens, thereby increasing the information content in selecting an appropriate ASIT. For many years, studies have been conducted on the immunomodulatory effect of vitamin D. These studies revealed the presence of a link between allergic rhinitis and vitamin D deficiency. In this regard, there is a strong need to assess the status of the population in terms of vitamin D for further examination of the effect of the vitamin D inclusion in the treatment regimen on the efficacy of ASIT. Objective — To evaluate the efficacy of ASIT in combination with vitamin D in polysensitized patients with seasonal allergic rhinitis in Karaganda Oblast, Kazakhstan. Material and Methods — Randomized controlled open-label study was conducted during July 2019 – September 2020 at Divera Allergy Center in Karaganda. Patients received sublingual ASIT: the experimental group received ASIT in combination with vitamin D, while comparison group received ASIT in accordance with the standard scheme. Clinical efficacy was monitored by assessing the severity of symptoms and the content of allergen-specific immunoglobulin E. ISAC test was employed to determine the allergen-specific immunoglobulin E. The significance of intergroup differences was determined by statistical methods: the nonparametric Mann-Whitney test for comparing independent groups and the Wilcoxon test for comparing dependent groups. Results — Vitamin D deficiency was revealed in the blood serum of patients in both groups (median value of 16.32 ng/ml and 15.65 ng/ml, respectively). An overall symptom severity score after treatment demonstrated statistically significant changes between the two groups (p=0.777; Mann-Whitney criterion). In the experimental group, the median of overall symptom severity score declined by 46% (from 11 points to 6 points), and in the comparison group by 22% (from 11.5 points to 9 points). Conclusion — As a result of our study, it was established that the adapted scheme of ASIT in combination with vitamin D in polysensitized patients with seasonal allergic rhinitis in Karaganda Oblast (Kazakhstan) was more effective, compared with the conventional scheme of ASIT. Hence, in patients with seasonal allergic rhinitis in the regions with known vitamin D deficiency, it is necessary to determine the vitamin D content with the purpose of its subsequent inclusion in the complex ASIT-based therapy.