Severe asthma exists despite suppressed tissue inflammation: findings of the U-BIOPRED study

The U-BIOPRED study is a multicentre European study aimed at a better understanding of severe asthma. It included three steroid-treated adult asthma groups (severe nonsmokers (SAn group), severe current/ex-smokers (SAs/ex group) and those with mild–moderate disease (MMA group)) and healthy controls (HC group). The aim of this cross-sectional, bronchoscopy substudy was to compare bronchial immunopathology between these groups. In 158 participants, bronchial biopsies and bronchial epithelial brushings were collected for immunopathologic and transcriptomic analysis. Immunohistochemical analysis of glycol methacrylate resin-embedded biopsies showed there were more mast cells in submucosa of the HC group (33.6 mm⁻ ²) compared with both severe asthma groups (SAn: 17.4 mm⁻ ², p<0.001; SAs/ex: 22.2 mm⁻ ², p=0.01) and with the MMA group (21.2 mm⁻ ², p=0.01). The number of CD4+ lymphocytes was decreased in the SAs/ex group (4.7 mm⁻ ²) compared with the SAn (11.6 mm⁻ ², p=0.002), MMA (10.1 mm⁻ ², p=0.008) and HC (10.6 mm⁻ ², p<0.001) groups. No other differences were observed. Affymetrix microarray analysis identified seven probe sets in the bronchial brushing samples that had a positive relationship with submucosal eosinophils. These mapped to COX-2 (cyclo-oxygenase-2), ADAM-7 (disintegrin and metalloproteinase domain-containing protein 7), SLCO1A2 (solute carrier organic anion transporter family member 1A2), TMEFF2 (transmembrane protein with epidermal growth factor like and two follistatin like domains 2) and TRPM-1 (transient receptor potential cation channel subfamily M member 1); the remaining two are unnamed. We conclude that in nonsmoking and smoking patients on currently recommended therapy, severe asthma exists despite suppressed tissue inflammation within the proximal airway wall

The role of adipokines in obesity-associated asthma

Obesity is a risk factor for the development of asthma and plays a role in disease control, severity and airway inflammation. The relationship between asthma and adiposity is multifactorial and incorporates in-utero conditions, genetic factors, comorbidities and inflammation secondary to excess adipose tissue. Adipocytes produce cytokines, termed adipokines, which play an important role in systemic inflammation and have been correlated to the development of asthma and disease severity. Retrospective analysis of trials using inhaled corticosteroids and an in vitro study using alveolar macrophages has associated obesity with corticosteroid insensitivity in asthma. The first part of this study looked at data taken from a large cohort of well-characterised severe asthmatics and compared patient demographics, disease characteristics, healthcare utilisation and medication according to body mass index (BMI). Lipid laden macrophages (LLMs) in bronchoalveolar lavage fluid (BALF) and perilipin as a marker of lipid droplets in endobronchial biopsies were analysed according to asthma severity and BMI. Finally, peripheral blood mononuclear cells (PBMCs) were used to study the effect of BMI on steroid sensitivity in patients with asthma using an in vitro model and the effects of adipokines (leptin, resistin and adiponectin) on the release of pro-inflammatory cytokines and corticosteroid response were assessed. Severe asthmatics are often overweight (29.3%) or obese (48.3%). Increasing BMI was associated with increasing medication use in terms of short-acting β2-agonist (SABA) use per day, nebulisers and oral corticosteroid requirements (both maintenance and short burst therapy). In addition, obese severe asthmatics reported greater gastro-oesophageal reflux disease (GORD) and were less likely to be in full time employment due to their asthma. LLMs are more prevalent in subjects with GORD which may explain the higher lipid laden macrophage index (LLMI) score seen in severe compared to mild/moderate asthmatics. Perilipin was expressed in the airway epithelium and submucosa in approximately half the study population. Greater expression was seen in the submucosa of asthmatic subjects compared to healthy controls. However, no significant correlations were noted in terms of asthma severity or BMI. Leptin, resistin and adiponectin were pro-inflammatory, in terms of CXCL8 release from PBMCs taken from asthmatics and healthy controls. PBMCs taken from severe asthmatics were less responsive to steroid suppression. Adiponectin induced IL-6, IL-10, CCL2, CCL3 and TNF-α release from PBMCs taken from asthmatics and healthy controls and IFN-γ, IL-1RA, CCL2, CCL3 and TNF-α release was suppressed by dexamethasone. Adiponectin induced CCL2 release and demonstrated relative corticosteroid insensitivity at dexamethasone 10-7 M in the severe asthma group. In conclusion, obesity related severe asthma is associated with more symptoms, a significant societal impact and patients are at risk of the many deleterious side effects of corticosteroid use. Leptin, resistin and adiponectin are pro-inflammatory and adiponectin may play an important role in modulating corticosteroid sensitivity.Open Acces

Pulmonary Fibrosis Secondary to FOLFOX Chemotherapy: A Case Report

A 54-year-old female presented with a 2-week history of increasing shortness of breath and fever. She had a history of a poorly differentiated sigmoid adenocarcinoma for which she underwent an anterior resection 6 months prior to admission, followed by 12 cycles of adjuvant FOLFOX chemotherapy. The patient was treated for a severe community-acquired pneumonia; however, she remained hypoxic. A chest CT revealed extensive right-sided fibrotic changes, tractional dilatation of the airways and ground glass density, which had developed since a staging CT scan performed 2 months previously. Although her symptoms improved with steroid therapy, repeat imaging revealed that right hydropneumothorax had developed, and this required the insertion of a chest drain. Following its successful removal, the patient continues to improve clinically and radiographically. The rapid onset and nature of these changes is consistent with a drug-induced fibrotic lung disease secondary to FOLFOX chemotherapy. The phenomenon is underreported and yet, it is relatively common: it occurs in approximately 10% of patients who are treated with antineoplastic agents, although information specifically relating to FOLFOX-induced pulmonary toxicity is limited. It is associated with significant morbidity and mortality, but is often hard to differentiate from other lung conditions, making the diagnosis a challenge. Pulmonary toxicity is an important complication associated with antineoplastic agents. It should be considered in any patient on a chemotherapeutic regimen who presents with dyspnoea and hypoxia in order to try to reduce the associated morbidity and mortality