Effect of TGF-β1 on eosinophils to induce cysteinyl leukotriene E4 production in aspirin-exacerbated respiratory disease

Unraveling cysteinyl leukotrienes and their receptors in inflammation through the brain-gut-lung axis

Cysteinyl leukotrienes (CysLTs), as potent lipid inflammatory mediators, play a pivotal role in systemic multi-organ inflammation and inter-organ communication through interactions with their receptors (CysLTRs). However, However, the function of CysLT3R is unclear and lacks a network of cross-organ metabolite interactions, and the clinical use of leukotriene receptor antagonists (LTRAs) has certain limitations. This review systematically synthesizes existing evidence and proposes future directions by clarifying receptor subtype specificity, optimizing targeted therapies, exploring CysLTs' applications in neuroimmunology, and elucidating the dual roles of CysLTs in chronic inflammation. It is indicated that CysLTs activate eosinophils, mast cells, and airway tuft cells, driving type 2 immune responses and mucus secretion in the lungs, thereby exacerbating respiratory diseases such as asthma. In the nervous system, CysLTs aggravate neurodegenerative disorders like cerebral ischemia and Alzheimer's disease by disrupting the blood-brain barrier, promoting glial activation, and inducing neuronal damage. In the gut, CysLTs regulate anti-helminth immunity via the tuft cell-ILC2 pathway and collaborate with prostaglandin D2 (PGD2) to modulate bile excretion and mucosal protection. Furthermore, CysLTs mediate communication through the gut-lung and gut-brain axes via metabolites such as succinate, contributing to cross-organ inflammatory regulation. In conclusion, this review highlights the complex roles of CysLTs in chronic inflammation, providing a theoretical foundation for precise intervention in multi-organ inflammatory diseases, which provides a theoretical framework for precision interventions in multi-organ inflammatory diseases and inspires interdisciplinary breakthroughs.

Association of the TGFB1 Gene Polymorphisms with Pain Symptoms and the Effectiveness of Platelet-Rich Plasma in the Treatment of Lateral Elbow Tendinopathy: A Prospective Cohort Study

The regenerative properties of platelet-rich plasma (PRP) result from the high concentration of growth factors, including transforming growth factor beta 1 (TGF-β1). Nevertheless, this form of therapy may not always be effective due to the variability in genetic factors. In this study, the association of TGFB1 gene polymorphisms with the effectiveness of lateral elbow tendinopathy (LET) treatment with PRP was investigated. The effectiveness of therapy was assessed using minimal clinically important difference (MCID) and patient-reported outcome measures (PROM), specifically visual analog scale (VAS), quick version of disabilities of the arm, shoulder, and hand score (QDASH), and patient-rated tennis elbow evaluation (PRTEE) for two years (in weeks 2, 4, 8, 12, 24, 52, and 104). The most effective therapy was noticed in CC rs2278422 genotype carriers, whereas carriers of AA, CC, and CC genotypes (rs12461895, rs4803455, rs2241717) showed more severe pain before therapy. Moreover, the analyses revealed an association of studied polymorphisms with such parameters of blood morphology as eosinophils (EOS), neutrophils (NEU), and monocytes (MONO). In conclusion, genotyping of rs2278422 variant may be a valuable diagnostic method for patient selection for PRP therapy, while genotyping of rs12461895, rs4803455, and rs2241717 polymorphisms may be used for prediction of increased risk of pain sensation.

Untargeted serum metabonomic reveals alleviated ovalbumin-induced asthma by Baijin Pingchuan through primary bile acid biosynthesis

OBJECTIVE

To investigate the effect of baijinpingchuan (, BJPC) on the asthma rat model and identify differential metabolites and disturbed metabolic pathways.

METHODS

The rats were categorized into six groups: control, dexamethasone (DEX), ovalbumin (OVA), and low-, median-, and high-dose BJPC. The rats, except for the control group, were initially treated with OVA to develop the asthma model, which was then activated using DEX, OVA, and low-, median-, and high-dose BJPC. Enzyme-linked immunosorbent assay kit was used to detect the expression of interleukin (IL)-33, IL-25, thymic stromal lymphopoietin (TSLP), and transforming growth factor-beta 1 (TGF-β1). Hematoxylin and eosin staining were performed to observe the pathological condition of the lung. Untargeted serum metabonomic analysis was conducted to identify differential metabolites and disturbed metabolic pathways.

RESULTS

High-dose BJPC significantly inhibited the expression of IL-33, IL-25, TSLP, and TGF-β1 (P < 0.0001). Further, high-dose BJPC improved inflammatory cell infiltration, which plays a similar role in asthma as DEX. OVA-induced and BJPC-treated rats were identified through 17 differential metabolites, especially cholic acid. Furthermore, primary bile acid biosynthesis was a significantly differential pathway in the mechanism of BJPC for treating asthma.

CONCLUSIONS

BJPC plays an anti-inflammation role in asthma, which might be a promising therapy through mediating primary bile acid biosynthesis.

Biomarkers of immediate drug hypersensitivity

Immediate drug hypersensitivity reactions (IDHRs) are a burden for patients and the health systems. This problem increases when taking into account that only a small proportion of patients initially labelled as allergic are finally confirmed after an allergological workup. The diverse nature of drugs involved will imply different interactions with the immunological system. Therefore, IDHRs can be produced by a wide array of mechanisms mediated by the drug interaction with specific antibodies or directly on effector target cells. These heterogeneous mechanisms imply an enhanced complexity for an accurate diagnosis and the identification of the phenotype and endotype at early stages of the reaction is of vital importance. Currently, several endophenotypic categories (type I IgE/non-IgE, cytokine release, Mast-related G-protein coupled receptor X2 (MRGPRX2) or Cyclooxygenase-1 (COX-1) inhibition and their associated biomarkers have been proposed. A precise knowledge of endotypes will permit to discriminate patients within the same phenotype, which is crucial in order to personalise diagnosis, future treatment and prevention to improve the patient's quality of life.

Long-term clinical outcomes of aspirin-exacerbated respiratory disease: Real-world data from an adult asthma cohort

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is a phenotype of severe asthma, but its disease course has not been well documented compared with that of aspirin-tolerant asthma (ATA).

OBJECTIVES

This study aimed to investigate the long-term clinical outcomes between AERD and ATA.

METHODS

AERD patients were identified by the diagnostic code and positive bronchoprovocation test in a real-world database. Longitudinal changes in lung function, blood eosinophil/neutrophil counts, and annual numbers of severe asthma exacerbations (AEx) were compared between the AERD and the ATA groups. Within a year after baseline, two or more severe AEx events indicated severe AERD, whereas less than two AEx events indicated nonsevere AERD.

RESULTS

Among asthmatics, 353 had AERD in which 166 and 187 patients had severe and nonsevere AERD, respectively, and 717 had ATA. AERD patients had significantly lower FEV1%, higher blood neutrophil counts, and higher sputum eosinophils (%) (all p < .05) as well as higher levels of urinary LTE4 and serum periostin, and lower levels of serum myeloperoxidase and surfactant protein D (all p < .01) than those with ATA. In a 10-year follow-up, the severe AERD group maintained lower FEV1% with more severe AEs than the nonsevere AERD group.

CONCLUSION AND CLINICAL RELEVANCE

We demonstrated that AERD patients presented poorer long-term clinical outcomes than ATA patients in real-world data analyses.

Urinary Leukotriene E4 as a Biomarker in NSAID-Exacerbated Respiratory Disease (N-ERD): a Systematic Review and Meta-analysis

PURPOSE OF REVIEW

Non-steroidal exacerbated respiratory disease (N-ERD) currently requires aspirin challenge testing for diagnosis. Urinary leukotriene E4 (uLTE₄) has been extensively investigated as potential biomarker in N-ERD. We aimed to assess the usefulness of uLTE₄ as a biomarker in the diagnosis of N-ERD.

RECENT FINDINGS

N-ERD, formerly known as aspirin-intolerant asthma (AIA), is characterised by increased leukotriene production. uLTE₄ indicates cysteinyl leukotriene production, and a potential biomarker in N-ERD. Although several studies and have examined the relationship between uLTE₄ and N-ERD, the usefulness of uLTE₄ as a biomarker in a clinical setting remains unclear.

FINDINGS

Our literature search identified 38 unique eligible studies, 35 were included in the meta-analysis. Meta-analysis was performed (i.e. pooled standardised mean difference (SMD) with 95% confidence intervals (95% CI)) and risk of bias assessed (implementing Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy (Cochrane DTA)). Data from 3376 subjects was analysed (1354 N-ERD, 1420 ATA, and 602 HC). uLTE₄ was higher in N-ERD vs ATA (n = 35, SMD 0.80; 95% CI 0.72-0.89). uLTE4 increased following aspirin challenge in N-ERD (n = 12, SMD 0.56; 95% CI 0.26-0.85) but not ATA (n = 8, SMD 0.12; CI - 0.08-0.33). This systematic review and meta-analysis showed that uLTE₄ is higher in N-ERD than ATA or HC. Likewise, people with N-ERD have greater increases in uLTE₄ following aspirin challenge. However, due to the varied uLTE₄ measurement and result reporting practice, clinical utility of these findings is limited. Future studies should be standardised to increase clinical significance and interpretability of the results.

Emerging Biomarkers Beyond Leukotrienes for the Management of Nonsteroidal Anti-inflammatory Drug (NSAID)-Exacerbated Respiratory Disease

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) is a unique condition characterized by aspirin/NSAID hypersensitivity, adult-onset asthma, and/or chronic rhinosinusitis with nasal polyps. Arachidonic acid metabolism dysregulation and intense eosinophilic/type 2 inflammation are central mechanisms in NERD. Studies have been conducted on various biomarkers, and urinary leukotriene E4 is considered the most available biomarker of NERD. However, the pathophysiology of NERD is heterogeneous and complex. Epithelial cells and platelets can interact with immune cells in NERD, and novel biomarkers related to these interactions have recently been investigated. We summarize emerging novel biomarkers of NERD and discuss their roles in the management of NERD.