Immune signatures predict response to house dust mite subcutaneous immunotherapy in patients with allergic rhinitis.

BACKGROUND: Identifying predictive biomarkers for allergen immunotherapy response is crucial for enhancing clinical efficacy. This study aims to identify such biomarkers in patients with allergic rhinitis (AR) undergoing subcutaneous immunotherapy (SCIT) for house dust mite allergy. METHODS: The Tongji (discovery) cohort comprised 72 AR patients who completed 1-year SCIT follow-up. Circulating T and B cell subsets were characterized using multiplexed flow cytometry before SCIT. Serum immunoglobulin levels and combined symptom and medication score (CSMS) were assessed before and after 12-month SCIT. Responders, exhibiting ≥30% CSMS improvement, were identified. The random forest algorithm and logistic regression analysis were used to select biomarkers and establish predictive models for SCIT efficacy in the Tongji cohort, which was validated in another Wisco cohort with 43 AR patients. RESULTS: Positive SCIT response correlated with higher baseline CSMS, allergen-specific IgE (sIgE)/total IgE (tIgE) ratio, and frequencies of Type 2 helper T cells, Type 2 follicular helper T (TFH2) cells, and CD23+ nonswitched memory B (BNSM) and switched memory B (BSM) cells, as well as lower follicular regulatory T (TFR) cell frequency and TFR/TFH2 cell ratio. The random forest algorithm identified sIgE/tIgE ratio, TFR/TFH2 cell ratio, and BNSM frequency as the key biomarkers discriminating responders from nonresponders in the Tongji cohort. Logistic regression analysis confirmed the predictive value of a combination model, including sIgE/tIgE ratio, TFR/TFH2 cell ratio, and CD23+ BSM frequency (AUC = 0.899 in Tongji; validated AUC = 0.893 in Wisco). CONCLUSIONS: A T- and B-cell signature combination efficiently identified SCIT responders before treatment, enabling personalized approaches for AR patients.

Untargeted metabolomic profiling identifies disease-specific and outcome-related signatures in chronic rhinosinusitis.

BACKGROUND: Although metabolomics provides novel insights into disease mechanisms and biomarkers, the metabolic alterations in local tissues affected by chronic rhinosinusitis (CRS) are unknown. OBJECTIVE: This study aimed to determine the metabolomic profiles of sinonasal tissues associated with different types of CRS and their treatment outcomes. METHODS: Untargeted metabolomic profiling was performed on sinonasal tissues obtained from patients with eosinophilic CRS with nasal polyps (CRSwNP), noneosinophilic CRSwNP or CRS without nasal polyps (CRSsNP), and controls. The messenger RNA (mRNA) levels of inflammatory cytokines in nasal tissues were detected by quantitative real-time reverse transcriptase PCR. Nasal polyp tissues were cultured ex vivo and treated with glutathione. RESULTS: Distinct metabolomic profiles were observed for the CRS subtypes. Eosinophilic CRSwNP had profoundly enhanced unsaturated fatty acid oxidization, which correlated with mucosal eosinophil numbers and IL-5 mRNA levels. Noneosinophilic CRSwNP was characterized by uric acid accumulation. Increased uric acid levels were positively correlated with mucosal neutrophil numbers and IFN-γ, IL-17A, IL-1ß, and IL-8 mRNA levels. Disrupted purine metabolism was specifically detected in CRSsNP. Reduced levels of amino acid metabolites were found in eosinophilic CRSwNP and CRSsNP, and were inversely associated with mucosal total inflammatory cell numbers and inflammatory cytokines. Compared to non-difficult-to-treat CRS, difficult-to-treat CRS had higher glutathione disulfide levels, which were positively correlated with IL-8 mRNA levels. Glutathione treatment reduced IL-8 mRNA expression in cultured nasal polyp tissues. CONCLUSIONS: Specific metabolic signatures are associated with different types of CRS, inflammatory patterns, and disease outcomes, which may provide novel insights into pathophysiologic mechanisms, subtype-specific biomarkers, and treatment targets of CRS.

Inflammatory Endotypes and Tissue Remodeling Features in Antrochoanal Polyps.

PURPOSE: The pathogenic mechanisms of antrochoanal polyps (ACPs) remain largely unknown. This study aimed to characterize inflammatory patterns and tissue remodeling features in ACPs. METHODS: Inflammatory cell infiltration and tissue edema severity as well as fibrin deposition in ACPs and bilateral eosinophilic and noneosinophilic nasal polyps (NPs) were studied with immunohistochemical and immunofluorescence staining. Cytokine levels in sinonasal tissues were detected with the Bio-Plex assay. The expression of coagulation and fibrinolytic markers was measured using reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assays. RESULTS: Compared to control tissues and bilateral eosinophilic and noneosinophilic NPs, ACPs had higher levels of neutrophil infiltration and expression of myeloperoxidase (MPO), interleukin (IL)-8 and interferon (IFN)-γ. In total, 94.4% of ACPs demonstrated an eosinophil cationic protein/MPO ratio of < 1, compared to 79.0% of noneosinophilic and 26% of eosinophilic NPs. Principle component and multiple correspondence analyses revealed a neutrophilic and type 1 inflammation pattern in ACPs. Compared to control tissues, edema scores and fibrin deposition were increased, whereas d-dimer and tissue plasminogen activator (tPA) levels were decreased in ACPs and bilateral NPs, with more prominent changes in ACPs even than in eosinophilic NPs. The tPA levels were negatively correlated with IFN-γ, IL-8, and MPO levels in ACPs. Neutrophils were the major cellular source of IFN-γ in ACPs, and the number of IFN-γ+ neutrophils was elevated in ACPs than in control tissues and bilateral eosinophilic and noneosinophilic NPs. CONCLUSIONS: ACPs are characterized by the neutrophilic and type 1 inflammation endotype. Neutrophil-derived IFN-γ is associated with reduced tPA production in ACPs.

Characterizing the Neutrophilic Inflammation in Chronic Rhinosinusitis With Nasal Polyps.

The mechanisms underlying neutrophilic inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP) remain poorly investigated. This study aimed to examine the factors that contribute to tissue neutrophilia in CRSwNP. The numbers of neutrophils and active caspase-3-positive apoptotic neutrophils in sinonasal tissues were assessed via immunofluorescence staining. The 95th percentile of tissue neutrophil numbers in control subjects was selected as a cut-off to define neutrophil-high (Neu-high) or neutrophil-low (Neu-low) nasal polyps (NPs). The levels of 34 inflammatory mediators in sinonasal tissues were analyzed using Bio-Plex assay. Purified human peripheral blood neutrophils were incubated with nasal tissue homogenates, and the apoptotic neutrophils were assessed via flow cytometry. The cut-off for Neu-high NPs was >10 myeloperoxidase positive cells/high-power field. Compared with Neu-low NPs, Neu-high NPs had higher tissue levels of IL-1ß, IL-1Ra, IL-6, IL-8, G-CSF, MCP-1, and MIP-1α, but lower levels of IL-5, IL-13, IgE, and eosinophils. Principal component and multiple correspondence analyses revealed mixed type 1, type 2, and type 3 endotypes for Neu-low NPs, and predominant type 1 and type 3 endotypes for Neu-high NPs. Neu-high NPs had lower percentages of apoptotic neutrophils than Neu-low NPs. The numbers of neutrophils and the percentages of apoptotic neutrophils correlated with G-CSF and IL-6 levels in the NPs. Tissue homogenates from Neu-high NPs, but not those from Neu-low NPs, suppressed neutrophil apoptosis in vitro, which was reversed by anti-G-CSF treatment. Tissue neutrophil numbers were associated with difficult-to-treat disease in patients with CRSwNP after surgery. We propose that G-CSF promotes neutrophilic inflammation by inhibiting neutrophil apoptosis in CRSwNP.