Identification of allergens from Aspergillus fumigatus-Potential association with lung damage in asthma.

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.

Longitudinal changes to quadriceps thickness demonstrate acute sarcopenia following admission to hospital for an exacerbation of chronic respiratory disease.

Acute admission to hospital for an exacerbation of chronic respiratory disease (CRD) may impair skeletal muscle mass and function. We measured quadriceps thickness (Qthick), as a surrogate marker of muscle mass, at hospital admission, discharge, 6 weeks and 3 months in 55 patients with CRD. Qthick fell by 8.3% during the period of hospitalisation, which was sustained at 6 weeks, and only partially recovered at 3 months. Sustained loss was most marked in patients readmitted during the follow-up period. Acute reduction in quadriceps muscle mass occurs during hospitalisation, with prolonged and variable recovery, which is prevented with subsequent hospital readmission.

The airway fungal microbiome in asthma.

BACKGROUND: Fungal involvement in asthma is associated with severe disease. The full spectrum of fungal species in asthma is not well described and is derived largely from insensitive culture techniques. OBJECTIVES: To use high-throughput sequencing to describe the airway mycobiota in asthmatics with and without fungal sensitization and healthy controls; to compare samples representing different airway compartments; to determine whether the mycobiota was influenced by the fungal composition of outdoor air; and to compare findings with clinically relevant outcomes. METHODS: We amplified the internal transcribed spacer region 2 of the nuclear ribosomal operon to identify the fungal species present. Ninety-seven subjects were recruited and provided sputum (83 asthmatics; 14 healthy subjects), with 29 also undergoing a bronchoscopy. A subset of airway samples were compared with matched outdoor air and mouthwash samples. RESULTS: Two hundred and six taxa at the species level were identified in sputum, most at low relative abundance. Aspergillus fumigatus, Candida albicans and Mycosphaerella tassiana had the highest relative abundances and were the most prevalent species across all subjects. The airway mycobiota consisted of a complex community with high diversity between individuals. Notable shifts in the balance of fungi detected in the lung were associated with asthma status, asthma duration and biomarkers of inflammation. Aspergillus tubingensis, a member of the Aspergillus niger species complex, was most prevalent from bronchoscopic protected brush samples and significantly associated with a low sputum neutrophilia. Cryptococcus pseudolongus, from the Cryptococcus humicola species complex, was more abundant from bronchoscopy samples than sputum, and differentially more abundant in asthma than health. CONCLUSIONS AND CLINICAL RELEVANCE: The airway mycobiota was dominated by a relatively small number of species, but was distinct from the oropharyngeal mycobiota and air samples. Members of the A. niger and C. humicola species complexes may play unexpected roles in the pathogenesis of asthma.

Clinical Outcomes in People with Difficult-to-Control Asthma Using Electronic Monitoring to Support Medication Adherence.

BACKGROUND: Nonadherence in difficult-to-control asthma can be identified using 7-day FeNO suppression testing where patients take additional fluticasone via Diskus with an Inhaler Compliance Assessment (INCA) acoustic monitoring device attached, and self-measure FeNO at home. However, this is inconvenient for patients attending a tertiary center and limited by FeNO meter availability. It is not known if this approach alters clinical outcomes. OBJECTIVES: To examine patient acceptability and the effectiveness of replacing usual combination inhaled corticosteroid (ICS)/long-acting ß2-agonist (LABA) therapy with a fluticasone/salmeterol Diskus 500+INCA for 28 days as the initial intervention, compared with the 7-day FeNO suppression test, and to explore clinical outcomes after INCA monitoring. METHODS: A service evaluation of FeNO suppression testing was undertaken in clinical practice. RESULTS: Twenty-one of 23 subjects offered replacement of their usual ICS/LABA with fluticasone/salmeterol+INCA as the initial intervention accepted and completed 28 days of monitoring. Fourteen (66.6%) patients reduced their FeNO by >42% (FeNO suppressors), accompanied by improvements in forced expiratory volume in 1 second, Asthma Control Questionnaire, and blood eosinophils, similar to the 7-day test (n = 74). Twenty-two of 62 (35.5%) FeNO suppressors progressed to biological therapy, compared with 24 of 33 (72.7%) nonsuppressors (P = .0006). FeNO suppressors taking maintenance prednisolone (n = 13) who did not receive biological therapy reduced the median baseline dose from 10 to 3 mg, with further reductions limited by adrenal suppression. CONCLUSION: Replacing existing inhaled therapy with fluticasone/salmeterol+INCA for 28 days is acceptable to the majority of people with difficult-to-control asthma and identifies prior medication nonadherence. INCA monitoring coupled with clinical support potentially improves patient adherence and asthma control, preventing unnecessary progression to biological therapy.