Precision Medicine Intervention in Severe Asthma (PRISM) study: molecular phenotyping of patients with severe asthma and response to biologics

Severe asthma represents an important clinical unmet need despite the introduction of biologic agents. Although advanced omics technologies have aided researchers in identifying clinically relevant molecular pathways, there is a lack of an integrated omics approach in severe asthma particularly in terms of its evolution over time. The collaborative Korea–UK research project Precision Medicine Intervention in Severe Asthma (PRISM) was launched in 2020 with the aim of identifying molecular phenotypes of severe asthma by analysing multi-omics data encompassing genomics, epigenomics, transcriptomics, proteomics, metagenomics and metabolomics. PRISM is a prospective, observational, multicentre study involving patients with severe asthma attending severe asthma clinics in Korea and the UK. Data including patient demographics, inflammatory phenotype, medication, lung function and control status of asthma will be collected along with biological samples (blood, sputum, urine, nasal epithelial cells and exhaled breath condensate) for omics analyses. Follow-up evaluations will be performed at baseline, 1 month, 4–6 months and 10–12 months to assess the stability of phenotype and treatment responses for those patients who have newly begun biologic therapy. Standalone and integrated omics data will be generated from the patient samples at each visit, paired with clinical information. By analysing these data, we will identify the molecular pathways that drive lung function, asthma control status, acute exacerbations and the requirement for daily oral corticosteroids, and that are involved in the therapeutic response to biological therapy. PRISM will establish a large multi-omics dataset of severe asthma to identify potential key pathophysiological pathways of severe asthma

Bronchoalveolar lavage cells.

<p>Individual and mean numbers of total cells (TOTAL) (Panel <b>A</b>), macrophages (MAC) (Panel <b>B</b>), neutrophils (NEU) (Panel <b>C</b>), lymphocytes (LYM) (Panel <b>D</b>), and eosinophils (EOS) (Panel <b>E</b>) in bronchoalveolar lavage (BAL) fluid for the 6 experimental groups. Panel <b>F</b>. Individual and mean inflammation scores in the airways and lungs. ^*P<0.05, ^**P<0.01, ^*** P<0.001. </p

Bronchoalveolar lavage fluid and plasma mediators.

<div><p>Individual and mean concentrations of malonaldehyde in bronchoalveolar lavage fluid (Panel <b>A</b>). Plasma levels of 8-hydroxy-deguanosine is shown in <b>Panel </b><b>B</b>.</p> <p>Individual and mean expression of IL-1β (Panel <b>C</b>), caspase-3 (Panel <b>D</b>), MMP-9 (Panel <b>E</b>), TGF-β (Panel <b>F</b>), SOD2 (Panel <b>G</b>) and HO-1(Panel <b>H</b>) in lung tissue measured by quantitative RT-PCR. ^*P<0.05, ^**P<0.01, ^*** P<0.001. </p></div

Evidence of emphysema.

<p>Representative photomicrographs of lung alveolar spaces in haematoxylin-eosin-stained sections of air-exposed mice (Panel <b>A</b>), PBS-pretreated ozone-exposed mice (Panel <b>B</b>), NAC-pretreated ozone-exposed mice (Panel <b>C</b>), air-exposed mice (Panel <b>D</b>), ozone-exposed PBS-treated mice (Panel <b>E</b>) ozone-exposed NAC-treated mice (Panel <b>F</b>). Scale bar = 40µm. Panel <b>G</b>. Individual and mean values of mean linear intercept, L_m, in the lung sections from the 6 experimental groups. ^*P<0.05, ^**P<0.01, ^*** P<0.001. </p

Lung mechanics.

<p>Individual and mean values of inspiratory capacity (IC)(Panel <b>A</b>), functional residual capacity (FRC) (Panel <b>B</b>), total lung capacity (TLC) (Panel <b>C</b>), chord compliance (C_chord) (Panel <b>D</b>), and percentage of forced expiratory volume (FEV) in first 25 and 50 ms of fast expiration (FEV₂₅ and FEV₅₀) of forced vital capacity (FVC)(Panels E,F). ^*compared with air control, ^*P<0.05, ^**P<0.01, ^***P<0.001. </p

Changes in airway wall.

<p>Individual and mean values of relative proportion of epithelium (Panel <b>A</b>), airway smooth muscle (ASM) (Panel <b>B</b>) and collagen (Panel <b>C</b>) in the bronchial wall measured by point-counting of Masson trichrome stained sections. ^*P<0.05, ^**P<0.01, ^*** P<0.001. </p

Airway hyperresponsiveness.

<p>Mean percentage increase in lung resistance (R_L) to increasing concentrations of acetylcholine is shown in <b>Panel </b><b>A</b>.. Three groups of mice were studied: air-exposed mice (n=8), PBS-pretreated ozone-exposed mice (n=7), NAC-pretreated ozone-exposed mice (n=8). ^*P<0.05, ^**P<0.01, ^***P<0.001 compared with air control. Data is expressed as means ±S.E.M. ○: Air exposure 6w,●: ozone-exposure 6w,▲:ozone-exposure and NAC-treatment 6w. Panel <b>B</b>. Mean percentage increase in lung resistance to increasing concentrations of acetylcholine, ^*P<0.05, ^**P<0.01, ^***P<0.001 compared with air control; ^≠P<0.05, ^≠≠P<0.01, ^≠≠≠P<0.001 compared with ozone-exposed NAC treated group. Data is expressed as means ±S.E.M. □:Air exposure 12w, ■: ozone-exposure 6w and then PBS-treatment 6w,▼: ozone-exposure 6w and then NAC-treatment 6w. Panel <b>C</b>. Individual and mean –log PC₁₅₀ of the six experimental groups. ^*P<0.05, ^**P<0.01. </p

Sputum ACE2, TMPRSS2 and FURIN gene expression in severe neutrophilic asthma

Background: Patients with severe asthma may have a greater risk of dying from COVID-19 disease. Angiotensin converting enzyme-2 (ACE2) and the enzyme proteases, transmembrane protease serine 2 (TMPRSS2) and FURIN, are needed for viral attachment and invasion into host cells. Methods: We examined microarray mRNA expression of ACE2, TMPRSS2 and FURIN in sputum, bronchial brushing and bronchial biopsies of the European U-BIOPRED cohort. Clinical parameters and molecular phenotypes, including asthma severity, sputum inflammatory cells, lung functions, oral corticosteroid (OCS) use, and transcriptomic-associated clusters, were examined in relation to gene expression levels. Results: ACE2 levels were significantly increased in sputum of severe asthma compared to mild-moderate asthma. In multivariate analyses, sputum ACE2 levels were positively associated with OCS use and male gender. Sputum FURIN levels were significantly related to neutrophils (%) and the presence of severe asthma. In bronchial brushing samples, TMPRSS2 levels were positively associated with male gender and body mass index, whereas FURIN levels with male gender and blood neutrophils. In bronchial biopsies, TMPRSS2 levels were positively related to blood neutrophils. The neutrophilic molecular phenotype characterised by high inflammasome activation expressed significantly higher FURIN levels in sputum than the eosinophilic Type 2-high or the pauci-granulocytic oxidative phosphorylation phenotypes. Conclusion: Levels of ACE2 and FURIN may differ by clinical or molecular phenotypes of asthma. Sputum FURIN expression levels were strongly associated with neutrophilic inflammation and with inflammasome activation. This might indicate the potential for a greater morbidity and mortality outcome from SARS-CoV-2 infection in neutrophilic severe asthma.</p

Correction to: Sputum ACE2, TMPRSS2 and FURIN gene expression in severe neutrophilic asthma (Respiratory Research, (2021), 22, 1, (10), 10.1186/s12931-020-01605-8)

An amendment to this paper has been published and can be accessed via the original article.</p