Treatment of allergic rhinitis with a mixed Chinese herbal formula via regulatory B cells: A prospective pilot study.

Background and aim: Mixed Chinese herbal formulas (CHFs) are commonly prescribed for allergic rhinitis (AR), but few studies explore their mechanisms. Prior research highlighted the immunomodulatory effects of a specific mixed CHF (Xin-yi-san + Xiao-qing-long-tang + Xiang-sha-liu-jun-zi-tang) in perennial AR by targeting neutrophils, dendritic cells, and CD4+ T lymphocytes. Here, we aimed to investigate the immunomodulatory mechanisms of mixed CHFs in treating AR by examining their effects on regulatory B (Breg) cells as a novel therapeutic approach. Experimental procedure: In this 3-month prospective pilot study, we assessed the immunomodulatory effect of a mixed CHF on patients with perennial AR, comparing the high-IgE (H-IgE; total serum IgE ≥200 IU/mL) and low-IgE (L-IgE; total serum IgE <200 IU/mL) groups. We measured the percentage of Breg cells and expression of CD1d, CD80 and CD86 using flow cytometry after the stimulation of B cells with CHF treatment. We also investigated the effects of mixed CHFs on cytokine expression by co-culturing Breg cells with CD4+CD25- T cells from perennial AR patients. Results: Forty-nine perennial AR patients enrolled, divided into H-IgE and L-IgE groups. Eight patients withdrew and the remaining 41 patients were included in the final analysis. Mixed CHF treatment elevated Breg cell percentages and their surface marker levels, leading to alterations in the cytokine spectra within the co-culture system of Breg cells and T cells from perennial AR patients in the H-IgE group. Conclusion: The results revealed that mixed CHFs exerted immunomodulatory mechanisms through the Breg cells to inhibit allergic reactions in the H-IgE group.