Background: Large numbers of CD8⁺T cells were observed in atopic dermatitis (AD) skin, and monocytes from AD patients showed increased prostaglandin E2 production. However, little is known about the expression of substance P (SP) and its receptor NK1R in blood leukocytes of patients with AD.Objective: To explore the expression of SP and NK1R in leukocytes of AD and the influence of allergens on SP and NK1R expression.Methods: The expression levels of SP and NK1R in patients with AD were examined by flow cytometry, ELISA and a mouse AD model.Results: The plasma SP level was 4.9-fold higher in patients with AD than in HC subjects. Both the percentage of SP expression in the population and mean fluorescence intensity (MFI) of SP expression were elevated in CD8⁺T cells in the blood of AD patients. However, both the CD14⁺NK1R⁺population and MFI of NK1R expression on CD14⁺cells were enhanced in the blood of AD patients. Allergens ASWE, HDME and PPE failed to up-regulate SP expression in CD8⁺T cells. However, allergens ASWE and HDME both enhanced NK1R expression on CD14⁺blood leukocytes regardless of AD or HC subjects. OVA-sensitized AD mice showed an elevated proportion and MFI of SP-expressing CD8⁺T cells in the blood, which agrees with the SP expression situation in human AD blood. Injection of SP into mouse skin did not up-regulate NK1R expression on monocytes.Conclusions: An elevated plasma SP level, up-regulated expression of SP and NK1R indicate that the SP/NK1R complex is important in the development of AD. Therefore, SP and NK1R antagonist or blocker agents may help to treat patients with AD.Trial registrationRegistration number: ChiCTR-BOC-16010279; Registration date: Dec., 28, 2016; retrospectively registered

Background: Emerging evidence indicates a link between gut dysbiosis and allergic rhinitis (AR) pathogenesis. Nevertheless, the mechanistic role of gut microbiota in AR progression requires further characterization. To address this, we employed an integrated multi-omics strategy to delineate gut microbial composition and metabolic signatures in AR patients. Methods: Fecal specimens from 23 AR patients and 15 matched healthy controls (total n = 38) were subjected to 16S rRNA gene sequencing to assess bacterial community structure, alongside untargeted metabolomic profiling of microbial metabolites. Spearman’s rank correlation analysis was applied to evaluate microbiota-metabolite interactions. Results: Allergic rhinitis patients exhibited altered gut microbial community structure (beta diversity, P < 0.05) with depletion of SCFA-producing genera such as Faecalibacterium and enrichment of pro-inflammatory taxa like Fusobacterium . Metabolomic profiling identified significant disturbances in pathways including pantothenate and CoA biosynthesis, glycolysis, and pyruvate metabolism. Key discriminatory metabolites included maltol and 4-coumaric acid. Integrative analysis revealed significant correlations between specific bacteria and metabolites, such as Faecalibacterium with D-phenyllactic acid (ρ = 0.515, q = 0.046). Conclusion: Our findings demonstrate that AR is associated with gut dysbiosis and metabolic dysfunction, highlighting the role of microbial-derived metabolites in immune regulation via the gut-nose axis. These insights support the potential for microbiota-targeted therapeutic strategies in AR management.

Background: Few studies reported the characteristics of house dust mite (HDM) sublingual immunotherapy (SLIT) adverse events (AEs) during early phase treatment. The aim of this prospective study was mainly to explore the characteristics of AEs in allergic rhinitis (AR) patients during 6 months of HDM SLIT.Methods: A total of 242 patients with AR were enrolled in this study. Telephone follow-up and administration were conducted in the every week of the first month, the third month, and the sixth month of SLIT treatment. Furthermore, the early efficacy, AEs, and compliance were analyzed in our study.Results: Overall, 70.25% (170/242) of the AR patients completed the study, while 29.75% (72/242) of the AR patients failed to complete the whole 6 months of SLIT treatment process. On the whole, symptoms improved in 87.65% (149/170) of patients including 34.12% (58/170) well-controlled and 53.53% (91/170) partially controlled. The correlation analysis results showed that the treatment effect was negatively correlated with the age (r = −0.1614, P = 0.0355). The AEs mainly occurred in the first month, comprised of local rashes, gastrointestinal reactions, and itching of mouth and tongue. Subgroup analysis in the first month showed the itching of mouth and tongue, gastrointestinal reactions, fatigue, and other AEs in ≥14 years old group (14–65 years old, n = 42) were significant differences when compared with that in the <14 years old group (4–13 years old, n = 128, all P < 0.05). In the study, the main reasons for terminated immunotherapy were drug inaccessibility, loss of follow-up and long course of treatment.Conclusion: Patients with AR who received HDM SLIT revealed an early efficacy after 6 months, with AEs mostly occurred in the first month.