Blood eosinophils, fractional exhaled nitric oxide and the risk of asthma attacks in randomised controlled trials: protocol for a systemic review and control arm patient-level meta-analysis for clinical prediction modelling

Prediction model protocols indicate better adherence to recommended guidelines for study conduct and reporting

BACKGROUND AND OBJECTIVE

Protocols are invaluable documents for any research study, especially for prediction model studies. However, the mere existence of a protocol is insufficient if key details are omitted. We reviewed the reporting content and details of the proposed design and methods reported in published protocols for prediction model research.

METHODS

We searched MEDLINE, Embase, and the Web of Science Core Collection for protocols for studies developing or validating a diagnostic or prognostic model using any modeling approach in any clinical area. We screened protocols published between Jan 1, 2022 and June 30, 2022. We used the abstract, introduction, methods, and discussion sections of The Transparent Reporting of a multivariable prediction model of Individual Prognosis Or Diagnosis (TRIPOD) statement to inform data extraction.

RESULTS

We identified 30 protocols, of which 28 were describing plans for model development and six for model validation. All protocols were open access, including a preprint. 15 protocols reported prospectively collecting data. 21 protocols planned to use clustered data, of which one-third planned methods to account for it. A planned sample size was reported for 93% development and 67% validation analyses. 16 protocols reported details of study registration, but all protocols reported a statement on ethics approval. Plans for data sharing were reported in 13 protocols.

CONCLUSION

Protocols for prediction model studies are uncommon, and few are made publicly available. Those that are available were reasonably well-reported and often described their methods following current prediction model research recommendations, likely leading to better reporting and methods in the actual study.

Biologic therapies for severe asthma with persistent type 2 inflammation

Asthma is a chronic inflammatory airways disease with reversible airflow obstruction, characterised in the majority by type 2 airway inflammation. Type 2 inflammation results in secretion of interleukin-4, -5 and -13 in the airways, recruitment of inflammatory cells (especially eosinophils and mast cells), and airway changes such as mucus hypersecretion and increased airway reactivity. Approximately 5 to 10% of people with asthma, despite optimal therapy and adherence to treatment with inhaled corticosteroids and long-acting beta2 agonists, are unable to obtain good symptom control and continue to experience exacerbations requiring oral corticosteroids; this is known as 'severe asthma'. In many cases, this is associated with persistent type 2 inflammation, indicated by the persistent elevation of blood eosinophils or fractional exhaled nitric oxide. In people with severe asthma and persistent type 2 inflammation, biologic (monoclonal antibody) therapy is indicated. Biologic therapies currently available in Australia for asthma are benralizumab, dupilumab, mepolizumab and omalizumab. They are administered subcutaneously and are generally well tolerated. Biologic asthma therapies are very effective in improving symptoms, and reducing the rate of exacerbations and use of oral corticosteroids, in people with severe asthma and persistent type 2 inflammation. Inhaled corticosteroid treatment should be continued in people using a biologic therapy.

Phenotyping the Responses to Systemic Corticosteroids in the Management of Asthma Attacks (PRISMA): protocol for an observational and translational pilot study

INTRODUCTION

Asthma and its associated exacerbation are heterogeneous. Although severe asthma attacks are systematically prescribed corticosteroids and often antibiotics, little is known about the variability of response to these therapies. Blood eosinophils and fractional exhaled nitric oxide (FeNO) are type 2 inflammation biomarkers that have established mechanistic, prognostic and theragnostic values in chronic asthma, but their utility in acute asthma is unclear. We speculate that the clinical and biological response to those treatments varies according to inflammometry and microbiological test results.

METHODS AND ANALYSIS

An observational longitudinal pilot study with multimodal clinical and translational assessments will be performed on 50 physician-diagnosed ≥12-year-old asthmatics presenting with an asthma attack and 12 healthy controls, including blood eosinophil count (venous and point-of-care (POC) capillary blood), FeNO and testing for airway infection (sputum cultures and POC nasopharyngeal swabs). People with asthma will be assessed on day 0 and after a 7-day corticosteroid course, with home monitoring performed in between. The primary analysis will be the change in the forced expiratory volume in 1 s according to type 2 inflammatory status (blood eosinophils ≥0.15×109/L and/or FeNO ≥25 ppb) after treatment. Key secondary analyses will compare changes in symptom scores and the proportion of patients achieving a minimal clinically important difference. Exploratory analyses will assess the relationship between clinical, lung function, inflammatory and microbiome parameters; satisfaction plus reliability indices of POC tests; and sex-gender variability in treatment response. Ultimately, this pilot study will serve to plan a larger trial comparing the clinical and biological response to systemic corticosteroids according to inflammatory biomarkers, offering valuable guidance for more personalised therapeutic strategies in asthma attacks.

ETHICS AND DISSEMINATION

The protocol has been approved by the Research Ethics Committee of the CIUSSS de l'Estrie-CHUS, Sherbrooke, Quebec, Canada (#2023-4687). Results will be communicated in an international meeting and submitted to a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05870215).

Toward a Predict and Prevent Approach in Obstructive Airway Diseases

Asthma and chronic obstructive pulmonary disease are currently diagnosed and treated after the demonstration of variable airflow limitation and symptoms. Under this framework, undiagnosed and unchecked airway inflammation is associated with recurrent acute attacks, airway remodeling, airflow limitation, adverse effects of corticosteroids, and impaired quality of life, ultimately leading to the collection of side effects termed "people remodeling." This one-size-fits-all damage control approach aims to control symptoms and treat exacerbations rather than modify the underlying disease process. The advent of highly effective therapies targeting proximal drivers of airway inflammation calls for a paradigm shift; upstream-acting therapies offer potential to alter the disease course and achieve clinical remission. We propose moving away from downstream firefighting and toward a "predict and prevent" model, measuring inflammation and providing anti-inflammatory therapy early, without waiting for further clinical deterioration. Much in the same way that high blood pressure and cholesterol are used to predict and prevent heart attacks, in asthma, elevated blood eosinophils and/or exhaled nitric oxide can be used to predict and prevent asthma attacks. We also advocate moving research further upstream by identifying patients with subclinical airway inflammation or disease who may be at risk of progressing to airflow limitation and associated morbidities and intervening early to prevent them. In summary, we call for a predict and prevent approach in obstructive airway disease.

Brain-Airway Interactions in Asthma

Asthma and brain interactions have long been appreciated and initially centered on increased anxiety and depression. Epidemiology studies have shown that early life stressors and situational disadvantages are risk factors for asthma. Conversely, the presence of asthma is a risk for mood and anxiety disorders, thus indicating a bidirectional effect between asthma and brain-related health. To substantiate asthma-brain interactions, validated instruments indicate and elucidate that communication likely exists between asthma and the brain. For example, provocation of an asthmatic response with an allergen challenge modulates how the brain responds to emotion-laden information. As detected by imaging studies, emotion-related brain activation is associated with generating airway inflammation. However, the specific mediators and processes mediating airway communication with the brain have yet to be established.Systemic inflammation is also associated with asthma and can affect other organ systems such as the cardiovascular system and the brain. Epidemiology studies have shown that asthma is a risk factor for dementia and Alzheimer's disease. In support of the importance of asthma as a risk factor for impaired cognitive function, imaging studies have shown changes to the white matter of the brain in asthma patients that resemble neuroinflammation changes seen in Alzheimer's disease and other neurodegenerative diseases. Therefore, bidirectional links between asthma and the brain exist with an important next research step to define asthma-brain interactions linked to neurodegeneration and dementia and explore whether treatments directed toward asthma-related inflammation can prevent the deleterious effects of asthma on brain health.

Study on the Relationship Between Bronchoalveolar Lavage Fluid Cell Count, Th1/Th2 Cytokines and Pulmonary Function in Patients with Cough Variant Asthma

OBJECTIVE

This study aimed to compare lung function and airway inflammation among cough variant asthma (CVA), chronic cough and classical asthma (CA) and investigate the relationship between these indicators and their possible mechanisms of action in the progression of CVA to CA.

METHODS

36 patients with chronic cough, 39 patients with CA, and 57 patients with CVA were included in this study. Pulmonary function tests, bronchial provocation tests and FeNO tests were performed. The patients' bronchoalveolar lavage fluid (BALF) was collected, the cells in BALF were counted, and the levels of Th1 and Th2 cytokines were detected.

RESULTS

The neutrophils, lymphocytes, and eosinophils in BALF in the CA and CVA groups were significantly higher than those in the chronic cough group. Also, they were negatively correlated with FEV1, FVC, and FEV1/FVC and positively correlated with IgE and FeNO. The expression of Th2-related cytokines was increased in CVA and CA patients, and it was positively correlated with FEV1, FVC and FEV1/FVC and negatively correlated with IgE and FeNO, while the results of Th1-related cytokines were the opposite of those for Th2-related cytokines.

CONCLUSION

CVA differs from asthma and chronic cough in terms of Th1/Th2 cytokines and lung function and provides a reference for understanding the disease mechanism of early clinical progression of CVA to CA.

Use of FeNO to predict anti-IL-5 and IL-5R biologics efficacy in a real-world cohort of adults with severe eosinophilic asthma

INTRODUCTION

Severe eosinophilic asthma (SEA) is associated with multiple exacerbations. Fractional exhaled nitric oxide (FeNO), a biomarker of airway T2 inflammation, is known to be correlated with the risk of exacerbations. While the use of FeNO is well established to predict the therapeutic response to dupilumab (anti-IL-4/IL-13), it remains uncertain for biologics targeting the IL-5 pathway.

METHODS

We conducted an observational, retrospective, monocentric analysis of adults with SEA who started mepolizumab (anti-IL-5) or benralizumab (anti-IL-5R) between January 1, 2016 and December 31, 2020.

RESULTS

Data were collected for 109 patients. All participants reported uncontrolled asthma with a median of 3 annual exacerbations and a median Asthma Control Test score of 12. They all had an initial blood eosinophilia >300/mm³, with a median at 610/mm³ (IQR 420-856). Patients with a baseline FeNO ≥50 ppb reported more exacerbations in the previous year than those with a FeNO <50 ppb (p = 0.02). After initiation of treatment, change in FeNO was not associated with therapeutic response. However, decrease in the annual number of exacerbations was significantly greater in patients with a baseline FeNO ≥50 ppb than in those with a baseline FeNO <50 ppb (-3.3 ± 2.7 vs -0.9 ± 2.4, respectively; p = 0.01). There was no association between baseline FeNO values and subsequent lung function, asthma control or reduction of oral corticosteroids use.

CONCLUSION

In this real-world cohort, adults with SEA who had a baseline FeNO ≥50 ppb experienced a greater decrease in exacerbations after 12 months of anti-IL-5 or IL-5R biologics than those with a FeNO <50 ppb.

Effect of Bairui Granule on Inflammatory Mediators in Induced Sputum, Leukotriene C4, and EOS in Peripheral Blood of Children with Cough Variant Asthma

Objective

To study the effect of Hanchuan Zupa granule combined with conventional western medicine in the treatment of children with bronchial asthma.

Methods

98 cases in Fengrun District People's Hospital of Tangshan City from June 2018 to February 2021 were selected. The control group was given oxygen therapy, antibiotics, and aerosol inhalation of quick acting β 2 receptor agonist, glucocorticoid, and other conventional western medicine treatment, while the observation group was treated with Bairui granule on the basis of the control group. The course of treatment of the two groups was 1 week.

Results

After treatment, the levels of sputum IL-4, IL-17, neu, and ECP in the two groups decreased, and the observation group was lower than the control group (P < 0.05). The levels of EOS, CXCR4, LTB4, and SDF-1 in peripheral blood of the two groups were lower than those in the control group (P < 0.05). The daytime cough, night cough, and TCM syndrome scores of the two groups were decreased, and the observation group was lower than the control group (P < 0.05).

Conclusion

Bairui granule combined with conventional western medicine in the treatment of children with bronchial asthma, the curative effect is worthy of affirmation, can effectively improve cough symptoms, reduce EOS, CXCR, LTB4, SDF-1 levels, inhibit airway inflammation, and has good clinical application value.