Elevated Circulating CD4+CD25+CD127-/low Regulatory T Cells in Patients with Non-asthmatic Eosinophilic Bronchitis

Mendelian randomization analysis of two samples to determine the impact of immune cells on bronchitis

Bronchitis is a common respiratory disease characterized by acute inflammation, edema, and necrosis of the small airways, leading to a significant pathological burden. Immune cells play a crucial role in combating bronchitis. This study aims to explore the causal relationship between immune cells and bronchitis using the Mendelian randomization approach. In this study, we screened 18,183 single nucleotide polymorphisms highly associated with immune cells and employed 5 Mendelian randomization methods to assess the potential causal link between different types of immune cells and bronchitis. Additionally, the study utilized inverse variance weighting and MR-Egger regression analysis to evaluate the heterogeneity and robustness of the causal estimates. The study found a significant causal association between 28 types of immune cells and the risk of bronchitis. These cell types mainly included T cells, monocytes, and B cells. For instance, CD25 on B cells and CD25 on IgD+ were associated with an increased risk of bronchitis, whereas IgD+ CD24- B cells and CD33- HLA DR- AC showed a protective effect against bronchitis. Moreover, the study validated the robustness of these findings through leave-one-out analysis and the MR-Egger method, and quantitatively illustrated the impact of immune cells on the risk of bronchitis through forest plots. This study reveals the dual role of immune cells in bronchitis. The identified types of immune cells may increase the risk of bronchitis by promoting inflammatory responses and cell-mediated immune reactions, while other cell types may offer protection by promoting immune balance and effective defense.

Approaches for Performance Verification Toward Standardization of Peripheral Blood Regulatory T-Cell Detection by Flow Cytometry

CONTEXT.—

Regulatory T-cell (Treg) detection in peripheral blood, based on flow cytometry, is invaluable for diagnosis and treatment of immune-mediated diseases. However, there is a lack of reliable methods to verify the performance, which is pivotal toward standardization of the Tregs assay.

OBJECTIVE.—

To conduct standardization studies and verify the performance of 3 commercially available reagent sets for the Tregs assay based on flow cytometry and agreement analysis for Treg detection across the different reagent sets.

DESIGN.—

The analytical performance of Tregs assay using reagent sets supplied by 3 manufacturers was evaluated after establishing the gating strategy and determining the optimal antibody concentration. Postcollection sample stability was evaluated, as well as the repeatability, reproducibility, reportable range, linearity, and assay carryover. Agreement between the different assays was assessed via Bland-Altman plots and linear regression analysis. The relationship between the frequency of CD4+CD25+CD127low/- Tregs and CD4+CD25+Foxp3+ Tregs was evaluated.

RESULTS.—

The postcollection sample stability was set at 72 hours after collection at room temperature. The accuracy, repeatability, reproducibility, and accuracy all met the requirements for clinical analysis. Excellent linearity, with R2 ≥0.9 and no assay carryover, was observed. For reportable range, a minimum of 1000 events in the CD3+CD4+ gate was required for Tregs assay. Moreover, the results for Tregs labeled by antibodies from the 3 manufacturers were in good agreement. The percentage of CD4+CD25+CD127low/- Tregs was closely correlated with CD4+CD25+Foxp3+ Tregs.

CONCLUSIONS.—

This is the first study to evaluate systematically the measurement performance of Tregs in peripheral blood by flow cytometry, which provides a practical solution to verifying the performance of flow cytometry-based immune monitoring projects in clinical practice.

Correlation analysis between serum total IgE and FeNO and idiosyncratic reaction in bronchiolitis

OBJECTIVE

This article focused on the correlation between the changes of serum total Immunoglobulin E (IgE) and Fractional exhaled Nitric Oxide (FeNO) and idiosyncratic reactions in children with bronchiolitis.

METHODS

One hundred children with bronchiolitis and fifty healthy children were enrolled. Serum total IgE and FeNO were assessed, and the diagnostic value for bronchiolitis and the correlation with the severity of bronchiolitis were analyzed. Bronchiolitis children were divided into idiosyncratic + bronchiolitis and non-idiosyncratic + bronchiolitis groups, the relationship between serum total IgE and FeNO and idiosyncratic reaction was determined, and the diagnostic value of serum total IgE and FeNO for idiosyncratic bronchiolitis was examined.

RESULTS

FeNO in bronchiolitis children was lower than that in healthy children but there was no significant difference in serum total IgE levels between the two populations. Serum total IgE increased while FeNO decreased with the aggravation of bronchiolitis in bronchiolitis children. The serum total IgE was positively correlated while FeNO was negatively correlated with the severity of bronchiolitis. Serum total IgE was higher in children with idiosyncratic bronchiolitis, but serum total IgE and FeNO were not the risk factors for idiosyncratic bronchiolitis; Area Under the Curve (AUC) of serum total IgE and FeNO for the diagnosis of idiosyncratic bronchiolitis was less than 0.7.

CONCLUSION

Serum total IgE and FeNO in children with bronchiolitis are related to disease severity and idiosyncratic reaction. FeNO has a diagnostic value for bronchiolitis, but not for idiosyncratic bronchiolitis.

Transfusion-induced platelet antibodies and regulatory T cells in multiply transfused patients

Background

Platelet transfusion refractoriness (PTR) remains a difficult problem in patients requiring long‐term platelet supportive care. However, there are little data on the frequency of platelet antibodies in multiply transfused Chinese patients. Moreover, the relationship between peripheral regulatory T cells (Tregs) and PTR remains unclear.

Methods

We retrospectively studied the frequency of alloimmunization against platelet antigens in patients receiving multiple transfusions between 2013 and 2017. Monoclonal antibody solid‐phase platelet antibody test (MASPAT) kits were used to screen for platelet antibodies before each platelet transfusion. Peripheral Tregs and CD4⁺CD25⁺CD127⁻ T cells were detected by flow cytometry, while transforming growth factor‐beta (TGF‐β) and interleukin (IL)‐17 cytokines were detected by enzyme‐linked immunosorbent assay.

Results

A total of 399 patients who met the inclusion criteria were enrolled for the analysis of platelet antibodies and refractoriness. Among these patients, 10 (2.5%) were positive for platelet antibodies before transfusion and 47 (11.8%) became antibody‐positive during the study period. The number of alloimmunized patients was significantly higher in patients with hematological disease as compared with other disease groups (p < 0.05). Refractoriness and alloimmunization occurred in 77 (19.3%) and 22 (28.6%) patients, respectively. There were no significant differences in CD4⁺, CD8⁺, and CD4⁺CD25⁺CD127⁻ T cell numbers and plasma levels of TGF‐β1 and IL‐17 between patients with PTR and the control group.

Conclusions

Refractoriness was common in patients undergoing multiple platelet transfusions (19.3%), with alloimmunization observed in 28.6% of patients. However, Tregs in peripheral blood may not play a key role in PTR.

An initial assessment of the involvement of transglutaminase2 in eosinophilic bronchitis using a disease model developed in C57BL/6 mice

The detailed pathogenesis of eosinophilic bronchitis (EB) remains unclear. Transglutaminase 2 (TG2) has been implicated in many respiratory diseases including asthma. Herein, we aim to assess preliminarily the relationship of TG2 with EB in the context of the development of an appropriate EB model through ovalbumin (OVA) sensitization and challenge in the C57BL/6 mouse strain. Our data lead us to propose a 50 μg dose of OVA challenge as appropriate to establish an EB model in C57BL/6 mice, whereas a challenge with a 400 μg dose of OVA significantly induced asthma. Compared to controls, TG2 is up-regulated in the airway epithelium of EB mice and EB patients. When TG2 activity was inhibited by cystamine treatment, there were no effects on airway responsiveness; in contrast, the lung pathology score and eosinophil counts in bronchoalveolar lavage fluid were significantly increased whereas the cough frequency was significantly decreased. The expression levels of interleukin (IL)-4, IL-13, IL-6, mast cell protease7 and the transient receptor potential (TRP) ankyrin 1 (TRPA1), TRP vanilloid 1 (TRPV1) were significantly decreased. These data open the possibility of an involvement of TG2 in mediating the increased cough frequency in EB through the regulation of TRPA1 and TRPV1 expression. The establishment of an EB model in C57BL/6 mice opens the way for a genetic investigation of the involvement of TG2 and other molecules in this disease using KO mice, which are often generated in the C57BL/6 genetic background.