Recent Submissions

  • Identification of allergens from aspergillus fumigatus-potential association with lung damage in asthma

    Bourne, Michelle; Monteiro, William (2024-02-09)
    Background: Component-resolved diagnosis allows detection of IgE sensitization having the advantage of reproducibility and standardization compared to crude extracts. The main disadvantage of the traditional allergen identification methods, 1- or 2-dimensional western blotting and screening of expression cDNA libraries with patients' IgEs, is that the native structure of the protein is not necessarily maintained. Methods: We used a novel immunoprecipitation technique in combination with mass spectrometry to identify new allergens of Aspergillus fumigatus. Magnetic Dynabeads coupled with anti-human IgE antibodies were used to purify human serum IgE and subsequently allergens from A. fumigatus protein extract. Results: Of the 184 proteins detected by subsequent mass peptide fingerprinting, a subset of 13 were recombinantly expressed and purified. In a panel of 52 A. fumigatus-sensitized people with asthma, 23 non-fungal-sensitized asthmatics and 18 healthy individuals, only the former showed an IgE reaction by immunoblotting and/or ELISA. We discovered 11 proteins not yet described as A. fumigatus allergens, with fructose-bisphosphate aldolase class II (FBA2) (33%), NAD-dependent malate dehydrogenase (31%) and Cu/Zn superoxide dismutase (27%) being the most prevalent. With respect to these three allergens, native versus denatured protein assays indicated a better recognition of the native proteins. Seven of 11 allergens fulfilled the WHO/IUIS criteria and were accepted as new A. fumigatus allergens. Conclusion: In conclusion, we introduce a straightforward method of allergen identification from complex allergenic sources such as A. fumigatus by immunoprecipitation combined with mass spectrometry, which has the advantage over traditional methods of identifying allergens by maintaining the structure of the proteins.
  • Inhaler steroid use changes oral and airway bacterial and fungal microbiome profile in asthma patients

    Pur Ozyigit, Leyla (2023-10-16)
    Introduction: The full spectrum of bacterial and fungal species in adult asthma and the effect of inhaled corticosteroid use is not well described. The aim was to collect mouthwash and induced sputum samples from newly diagnosed asthma patients in the pretreatment period and in chronic asthma patients while undergoing regular maintenance inhaled corticosteroid therapy, in order to demonstrate the bacterial and fungal microbiome profile. Methods: The study included 28 asthmatic patients on inhaler steroid therapy, 25 steroid-naive asthmatics, and 24 healthy controls. Genomic DNA was isolated from induced sputum and mouthwash samples. Analyses were performed using bacterial primers selected from the 16S rRNA region for the bacterial genome and "panfungal" primers selected from the 5.8S rRNA region for the fungal genome. Results: Dominant genera in mouthwash samples of steroid-naive asthmatics were Neisseria, Haemophilus, and Rothia. The oral microbiota of asthmatic patients on inhaler steroid treatment included Neisseria, Rothia, and Veillonella species. Abundant genera in induced sputum samples of steroid-naive asthma patients were Actinomyces, Granulicatella, Fusobacterium, Peptostreptococcus, and Atopobium. Sputum microbiota of asthma patients taking inhaler steroids were dominated by Prevotella and Porphyromonas. Mucor plumbeus and Malassezia restricta species were abundant in the airways of steroid-naive asthma patients. Choanephora infundibulifera and Malassezia restricta became dominant in asthma patients taking inhaled steroids. Conclusion: The oral and airway microbiota consist of different bacterial and fungal communities in healthy and asthmatic patients. Inhaler steroid use may influence the composition of the oral and airway microbiota.
  • Enabling adults with severe asthma to exercise: a qualitative examination of the challenges for patients and health care professionals

    Evans, Rachael A; Bradding, Peter; Green, Ruth H; Murphy, Anna C; Singh, Sally J (2023-11)
    Background: Adults living with severe asthma have lower physical activity levels, particularly high-intensity physical activity, compared with their healthy peers. Physical inactivity is associated with increased morbidity and mortality. Objective: To understand patient and health care professional attitudes toward exercise and physical activity to inform future strategies for the improvement of healthy lifestyle behaviors, including exercise. Methods: Participants recruited from a specialist difficult asthma service were interviewed individually, and health care professionals (HCPs) from primary care, secondary care, and a tertiary center were invited to attend focus groups. Interviews and focus groups were transcribed verbatim. We performed thematic analysis on interviews and focus groups separately, followed by an adapted framework analysis to analyze datasets together. Results: Twenty-nine people with severe asthma participated in a semi-structured interview. A total of 51 HCPs took part in eight focus groups across the East Midlands, United Kingdom. Final analysis resulted in three major themes: barriers to exercise and exercise counseling - in which patients and HCPs identified disease and non-disease factors affecting those living with severe asthma; attitudes toward HCP support for exercise - highlighting education needs for HCPs and preference for supervised exercise programs; and areas for system improvement in supporting patients and HCPs - challenges exist across health sectors that limit patient support are described. Conclusions: Patients identified the important role of HCPs in supporting and advising on lifestyle change. Despite a preference for supervised exercise programs, both patient and HCP barriers existed. To meet patients' varied support needs, improved integration of services is required and HCP skills need extending.
  • Picturing asthma in Turkey: results from the Turkish adult asthma registry

    Pur Ozyigit, Leyla
    Introduction: National data on asthma characteristics and the factors associated with uncontrolled asthma seem to be necessary for every country. For this purpose, we developed the Turkish Adult Asthma Registry for patients with asthma aiming to take a snapshot of our patients, thereby assigning the unmet needs and niche areas of intervention. Methods: Case entries were performed between March 2018 and March 2022. A web-based application was used to record data. Study outcomes were demographic features, disease characteristics, asthma control levels, and phenotypes. Results: The registry included 2053 patients from 36 study centers in Turkey. Female subjects dominated the group (n = 1535, 74.8%). The majority of the patients had allergic (n = 1158, 65.3%) and eosinophilic (n = 1174, 57.2%) asthma. Six hundred nineteen (32.2%) of the patients had obese asthma. Severe asthma existed in 670 (32.6%) patients. Majority of cases were on step 3-5 treatment (n: 1525; 88.1%). Uncontrolled asthma was associated with low educational level, severe asthma attacks in the last year, low FEV1, existence of chronic rhinosinusitis and living in particular regions. Conclusion: The picture of this registry showed a dominancy of middle-aged obese women with moderate-to-severe asthma. We also determined particular strategic targets such as low educational level, severe asthma attacks, low FEV1, and chronic rhinosinusitis to decrease uncontrolled asthma in our country. Moreover, some regional strategies may also be needed as uncontrolled asthma is higher in certain regions. We believe that these data will guide authorities to reestablish national asthma programs to improve asthma service delivery.
  • Functionality of natural killer cells in obese asthma phenotypes

    Pur Ozyigit, Leyla (2022-03-31)
    Background: Obesity-associated asthma (OA) is a difficult to treat asthma phenotype due to its severity and poor response to inhaled steroids. Early-onset allergic (EoOA) and late-onset non-allergic (LoOA) OA are suggested subtypes of this phenotype. Natural Killer (NK) cells are key elements of innate immunity involved in cytotoxicity and immune regulation, with uncertain role in OA pathogenesis. Methods: Early-onset allergic and LoOA patients together with obese non-asthmatic (ONA) controls have been enrolled in the study. Peripheral blood samples have been collected for analysis. Percentages of total NK cells, CD3- CD56dim and CD3- CD56bright NK cell subsets, cytotoxic activity, intracellular interferon-γ, interleukin (IL)-10, IL-13, IL-17 secretion and activatory receptors (NKG2D, NKp46i and NKp44) have been investigated by flow cytometry. The effect of IL-12 and IL-23 stimulation on NK cells and intracellular cytokines in different groups have also been analysed and compared with unstimulated conditions. Results: Results of ONA (n = 5, age 42 ± 8), EoOA (n = 5, age 42 ± 10) and LoOA (n = 8, age 46 ± 8) patients have analysed. Body Mass Index has been found to be negatively correlated with CD69 (p = .022, r = -0.534). NKG2D receptor has been significantly low in CD56dim cells of asthma population (p = .046). NKp44 receptor expression has increased after IL-12 stimulation in EoOA and control group (p = .02). Intracellular IL-10 content has increased in LoOA and control subjects (p = .018, p = .03) but not in the EoOA group. Intracellular IL-17 level has found be higher in allergic OA group. LoOA patients showed a decreased NK cytotoxicity compared with the early-onset asthma group (p = .05). Conclusion: Our study suggests an impaired NK receptor expression, activation and reduced cytotoxicity in OA patients together with variances between different subtypes of this phenotype. This data would be beneficial for tailoring a more personalized treatment strategy combatting steroid resistance and frequent exacerbations in this group of patients.
  • Outcomes following SARS-CoV-2 infection in patients with primary and secondary immunodeficiency in the UK

    Mahabir, Shanti; Price, Arthur (2022-01-28)
    In March 2020, the United Kingdom Primary Immunodeficiency Network (UKPIN) established a registry of cases to collate the outcomes of individuals with PID and SID following SARS-CoV-2 infection and treatment. A total of 310 cases of SARS-CoV-2 infection in individuals with PID or SID have now been reported in the UK. The overall mortality within the cohort was 17.7% (n = 55/310). Individuals with CVID demonstrated an infection fatality rate (IFR) of 18.3% (n = 17/93), individuals with PID receiving IgRT had an IFR of 16.3% (n = 26/159) and individuals with SID, an IFR of 27.2% (n = 25/92). Individuals with PID and SID had higher inpatient mortality and died at a younger age than the general population. Increasing age, low pre-SARS-CoV-2 infection lymphocyte count and the presence of common co-morbidities increased the risk of mortality in PID. Access to specific COVID-19 treatments in this cohort was limited: only 22.9% (n = 33/144) of patients admitted to the hospital received dexamethasone, remdesivir, an anti-SARS-CoV-2 antibody-based therapeutic (e.g. REGN-COV2 or convalescent plasma) or tocilizumab as a monotherapy or in combination. Dexamethasone, remdesivir, and anti-SARS-CoV-2 antibody-based therapeutics appeared efficacious in PID and SID. Compared to the general population, individuals with PID or SID are at high risk of mortality following SARS-CoV-2 infection. Increasing age, low baseline lymphocyte count, and the presence of co-morbidities are additional risk factors for poor outcome in this cohort.
  • Identification of redundancy between human FcεRIβ and MS4A6A proteins points toward additional complex mechanisms for FcεRI trafficking and signaling

    Bradding, Peter
    Background: Allergic diseases are triggered by signaling through the high-affinity IgE receptor, FcεRI. In both mast cells (MCs) and basophils, FcεRI is a tetrameric receptor complex comprising a ligand-binding α subunit (FcεRIα), a tetraspan β subunit (FcεRIβ, MS4A2) responsible for trafficking and signal amplification, and a signal transducing dimer of single transmembrane γ subunits (FcεRIγ). However, FcεRI also exists as presumed trimeric complexes that lack FcεRIβ and are expressed on several cell types outside the MC and basophil lineages. Despite known differences between humans and mice in the presence of the trimeric FcεRI complex, questions remain as to how it traffics and whether it signals in the absence of FcεRIβ. We have previously reported that targeting FcεRIβ with exon-skipping oligonucleotides eliminates IgE-mediated degranulation in mouse MCs, but equivalent targeting in human MCs was not effective at reducing degranulation. Results: Here, we report that the FcεRIβ-like protein MS4A6A exists in human MCs and compensates for FcεRIβ in FcεRI trafficking and signaling. Human MS4A6A promotes surface expression of FcεRI complexes and facilitates degranulation. MS4A6A and FcεRIβ are encoded by highly related genes within the MS4A gene family that cluster within the human gene loci 11q12-q13, a region linked to allergy and asthma susceptibility. Conclusions: Our data suggest the presence of either FcεRIβ or MS4A6A is sufficient for degranulation, indicating that MS4A6A could be an elusive FcεRIβ-like protein in human MCs that performs compensatory functions in allergic disease.
  • BSACI 2021 guideline for the management of egg allergy

    Ball, Heidi
    This guideline advises on the management of patients with egg allergy. Most commonly egg allergy presents in infancy, with a prevalence of approximately 2% in children and 0.1% in adults. A clear clinical history will confirm the diagnosis in most cases. Investigation by measuring egg-specific IgE (by skin prick testing or specific IgE assay) is useful in moderate-severe cases or where there is diagnostic uncertainty. Following an acute allergic reaction, egg avoidance advice should be provided. Egg allergy usually resolves, and reintroduction can be achieved at home if reactions have been mild and there is no asthma. Patients with a history of severe reactions or asthma should have reintroduction guided by a specialist. All children with egg allergy should receive the MMR vaccine. Most adults and children with egg allergy can receive the influenza vaccine in primary care, unless they have had anaphylaxis to egg requiring intensive care support. Yellow Fever vaccines should only be considered in egg-allergic patients under the guidance of an allergy specialist. This guideline was prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and is intended for allergists and others with a special interest in allergy. The recommendations are evidence based. Where evidence was lacking, consensus was reached by the panel of specialists on the committee. The document encompasses epidemiology, risk factors, diagnosis, treatment, prognosis and co-morbid associations.
  • Unexplained peripheral blood eosinophilia with gastrointestinal symptoms

    Wardlaw, Andrew; Myers, Bethan; Rathbone, Barrie; Siddiqui, Salman; Wurm, Peter (2021)
    No abstract available.