M2 Macrophages Upregulated by Allergen Exposure in Seasonal Allergic Rhinitis.

INTRODUCTION: Macrophages play a central role in balancing the immune response by switching phenotypes between the M1 and M2 profiles according to a delicate equilibrium. Based on a previous clinical trial (NCT03649139), this study aimed to evaluate the change in M2 macrophages during pollen exposure in seasonal allergic rhinitis (SAR). METHODS: Nasal symptom scores were recorded. Peripheral M2 macrophages were investigated according to cell surface markers, and M2-associated cytokine/chemokine release in serum and nasal secretion were assessed. In vitro pollen stimulation tests were performed, and polarized macrophage subsets were analyzed by flow cytometry. RESULTS: Compared to baseline, the percentage of peripheral CD163+ M2 macrophages in CD14+ monocytes increased during the pollen season (p < 0.001) and at the end of treatment (p = 0.004) in the SLIT group. The percentage of CD206+CD86- M2 cells in M2 macrophages during the pollen season was higher than that at baseline and at the end of SLIT. On the other hand, the percentage of CD206-CD86+ M2 cells in M2 macrophages significantly increased at the end of treatment in the SLIT group compared to baseline (p = 0.049), the peak pollen period (p = 0.017), and the placebo group (p = 0.0023). M2-associated chemokines CCL26 and YKL-40 were significantly increased during the pollen season in the SLIT group and remained higher at the end of SLIT than at baseline. Correspondingly, in vitro study demonstrated that Artemisia annua promoted M2 macrophage polarization in pollen-induced AR patients. CONCLUSION: Significant M2 macrophage polarization was promoted when patients with SAR were exposed to the allergen, either naturally exposed in pollen seasons or subjectively continuously exposed during the course of SLIT.

The use of specific immunoglobulin E in nasal secretions for the diagnosis of allergic rhinitis.

OBJECTIVE: Although local specific immunoglobulin (sIgE) has been employed as a diagnostic criterion for allergic rhinitis (AR), the use of local sIgE has not been fully evaluated in the diagnosis of allergic rhinitis. The aim of this study was to evaluate the use of nasal secretion sIgE in the diagnosis of allergic rhinitis. METHODS: A total of 51 patients (27 males and 24 females, mean age = 33.3 years) with rhinitis symptoms were enrolled consecutively from the allergy-rhinology clinic of Beijing TongRen Hospital (Beijing, People's Republic of China). Questionnaires were completed by each participant at recruitment to record demographic data, nasal symptom severity, and physician-diagnosed comorbid asthma. The severity of nasal obstruction, rhinorrhea, sneezing, and nasal/eye itching was recorded according to a visual analogue scale (VAS) of 10 cm. Sensitization to Dermatophagoides pteronyssinus, Dermatophagoides farinae, mugwort, Candida albicans, Penicillium notatum, Alternaria, Cladosporium, and Aspergillus were assessed according to presence of sIgE antibodies to these allergens in serum and nasal secretions. RESULTS: VAS scores of the participants ranged from 11 to 25 (mean = 17), and 14 (27.5%) patients had comorbid asthma. Based on serum sIgE, 31 (60.8%) patients were allergic to mugwort, 14 (27.5%) to Dermatophagoides, and three (5.9%) to fungal allergens. Based on nasal secretion sIgE, 32 (62.7%) patients were allergic to mugwort, 12 (23.5%) to Dermatophagoides, and three (5.9%) to fungal allergens. The local mugwort sIgE level and serum mugwort sIgE level were positively correlated with each other and with VAS scores. CONCLUSION: sIgE level in nasal secretions of subjects with rhinitis is a reliable noninvasive alternative to serum sIgE for diagnosis of allergic rhinitis. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:E311-E315, 2018.