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- Amaral, Rita, et al.
(författare)
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Comparison of hypothesis- and data-driven asthma phenotypes in NHANES 2007-2012 : the importance of comprehensive data availability
- 2019
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Ingår i: Clinical and Translational Allergy. - : Wiley. - 2045-7022. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundHalf of the adults with current asthma among the US National Health and Nutrition Examination Survey (NHANES) participants could be classified in more than one hypothesis-driven phenotype. A data-driven approach applied to the same subjects may allow a more useful classification compared to the hypothesis-driven one.AimTo compare previously defined hypothesis-driven with newly derived data-driven asthma phenotypes, identified by latent class analysis (LCA), in adults with current asthma from NHANES 2007-2012.MethodsAdults (18years) with current asthma from the NHANES were included (n=1059). LCA included variables commonly used to subdivide asthma. LCA models were derived independently according to age groups: <40 and 40years old.ResultsTwo data-driven phenotypes were identified among adults with current asthma, for both age groups. The proportions of the hypothesis-driven phenotypes were similar among the two data-driven phenotypes (p>0.05). Class A <40years (n=285; 75%) and Class A 40years (n=462; 73%), respectively, were characterized by a predominance of highly symptomatic asthma subjects with poor lung function, compared to Class B <40years (n=94; 25%) and Class B 40years (n=170; 27%). Inflammatory biomarkers, smoking status, presence of obesity and hay fever did not markedly differ between the phenotypes.ConclusionBoth data- and hypothesis-driven approaches using clinical and physiological variables commonly used to characterize asthma are suboptimal to identify asthma phenotypes among adults from the general population. Further studies based on more comprehensive disease features are required to identify asthma phenotypes in population-based studies.
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- Amaral, Rita, et al.
(författare)
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Having concomitant asthma phenotypes is common and independently relates to poor lung function in NHANES 2007-2012
- 2018
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Ingår i: Clinical and Translational Allergy. - : BIOMED CENTRAL LTD. - 2045-7022. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Evidence for distinct asthma phenotypes and their overlap is becoming increasingly relevant to identify personalized and targeted therapeutic strategies. In this study, we aimed to describe the overlap of five commonly reported asthma phenotypes in US adults with current asthma and assess its association with asthma outcomes. Methods: Data from the National Health and Nutrition Examination Surveys (NHANES) 2007-2012 were used (n =30,442). Adults with current asthma were selected. Asthma phenotypes were: B-Eos-high [if blood eosinophils (B-Eos) >= 300/mm(3)]; FeNO-high (FeNO >= 35 ppb); B-Eos&FeNO-low (B-Eos < 150/mm(3) and FeNO < 20 ppb); asthma with obesity (AwObesity) (BMI >= 30 kg/m(2)); and asthma with concurrent COPD. Data were weighted for the US population and analyses were stratified by age (< 40 and >= 40 years old). Results: Of the 18,619 adults included, 1059 (5.6% [95% CI 5.1-5.9]) had current asthma. A substantial overlap was observed both in subjects aged < 40 years (44%) and >= 40 years (54%). The more prevalent specific overlaps in both age groups were AwObesity associated with either B-Eos-high (15 and 12%, respectively) or B-Eos&FeNO-low asthma (13 and 11%, respectively). About 14% of the current asthma patients were"non-classified". Regardless of phenotype classification, having concomitant phenotypes was significantly associated with (adjusted OR, 95% CI) >= 2 controller medications (2.03, 1.16-3.57), and FEV1 < LLN (3.21, 1.74-5.94), adjusted for confounding variables. Conclusions: A prevalent overlap of commonly reported asthma phenotypes was observed among asthma patients from the general population, with implications for objective asthma outcomes. A broader approach may be required to better characterize asthma patients and prevent poor asthma outcomes.
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- Dahlin, Joakim S, et al.
(författare)
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Lineage- CD34hi CD117int/hi FcϵRI+ cells in human blood constitute a rare population of mast cell progenitors
- 2016
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 127:4, s. 383-391
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are rare tissue-resident immune cells that are involved in allergic reactions, and their numbers are increased in the lungs of asthmatics. Murine lung mast cells arise from committed bone marrow-derived progenitors that enter the blood circulation, migrate through the pulmonary endothelium, and mature in the tissue. In humans, mast cells can be cultured from multipotent CD34(+) progenitor cells. However, a population of distinct precursor cells that give rise to mast cells has remained undiscovered. To our knowledge, this is the first report of human lineage(-) CD34(hi) CD117(int/hi) FcϵRI(+) progenitor cells, which represented only 0.0053% of the isolated blood cells in healthy individuals. These cells expressed integrin β7 and developed a mast cell-like phenotype, although with a slow cell division capacity in vitro. Isolated lineage(-) CD34(hi) CD117(int/hi) FcϵRI(+) blood cells had an immature mast cell-like appearance and expressed high levels of many mast cell-related genes as compared with human blood basophils in whole-transcriptome microarray analyses. Furthermore, serglycin, tryptase, and carboxypeptidase A mRNA transcripts were detected by quantitative RT-PCR. Altogether, we propose that the lineage(-) CD34(hi) CD117(int/hi) FcϵRI(+) blood cells are closely related to human tissue mast cells and likely constitute an immediate precursor population, which can give rise to predominantly mast cells. Furthermore, asthmatics with reduced lung function had a higher frequency of lineage(-) CD34(hi) CD117(int/hi) FcϵRI(+) blood mast cell progenitors than asthmatics with normal lung function.
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- Diamant, Zuzana, et al.
(författare)
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Toward clinically applicable biomarkers for asthma : An EAACI position paper
- 2019
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 74:10, s. 1835-1851
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation, structural, and functional abnormalities within the airways are key features of asthma. Although these processes are well documented, their expression varies across the heterogeneous spectrum of asthma. Type 2 inflammatory responses are characterized by increased levels of eosinophils, FeNO, and type 2 cytokines in blood and/or airways. Presently, type 2 asthma is the best-defined endotype, typically found in patients with allergic asthma, but surprisingly also in nonallergic patients with (severe) asthma. The etiology of asthma with non-type 2 inflammation is less clear. During the past decade, targeted therapies, including biologicals and small molecules, have been increasingly integrated into treatment strategies of severe asthma. These treatments block specific inflammatory pathways or single mediators. Single or composite biomarkers help to identify patients who will benefit from these treatments. So far, only a few inflammatory biomarkers have been validated for clinical application. The European Academy of Allergy & Clinical Immunology Task Force on Biomarkers in Asthma was initiated to review different biomarker sampling methods and to investigate clinical applicability of new and existing inflammatory biomarkers (point-of-care) to support diagnosis, targeted treatment, and monitoring of severe asthma. Subsequently, we discuss existing and novel targeted therapies for asthma as well as applicable biomarkers.
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- Heijkenskjöld-Rentzhog, Charlotte, et al.
(författare)
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New method for single-breath fraction of exhaled nitric oxide measurement with improved feasibility in preschool children with asthma
- 2015
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Ingår i: Pediatric Allergy and Immunology. - : Wiley. - 0905-6157 .- 1399-3038. ; 26:7, s. 662-667
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Respiratory societies recommend use of standardized methodologies for fraction of exhaled nitric oxide (FeNO) measurements in adults and children, but in preschoolers, feasibility remains a problem. The exhalation time needed to obtain steady-state FeNO is unclear. Our primary aim was to study the feasibility of an adapted single-breath FeNO method with age-adjusted exhalation times. We also studied the association between time to steady-state NO level and height, as well as FeNO in relation to asthma and current treatment with inhaled corticosteroids (ICS).METHODS: Sixty-three children aged 3-10 years performed FeNO measurements with a hand-held electrochemical device with a newly developed flow-control unit. Exhalation times were pre-adapted to age. Exhaled air was simultaneously sampled to a chemiluminescence analyzer to measure time to steady-state NO level.RESULTS: Eighty-one percent of the children achieved at least one approved measurement. From 4 years upwards, success rate was high (96%). Time to steady-state [NO] (median and interquartile range) was 2.5 s (2.4-3.5) at the age of 3-4 years and 3.5 s (2.7-3.8) at the age of 5-6 years. Height was associated with time to steady state (r(2) = 0.13, p = 0.02). FeNO (geometric mean [95% CI]) was higher in ICS-naïve asthmatic children (n = 19): 15.9 p.p.b. (12.2-20.9), than in both healthy controls (n = 8) 9.1 p.p.b. (6.6-12.4) and asthmatic subjects on treatment (n = 24) 11.5 p.p.b. (9.7-13.6).CONCLUSION: We found this adapted single-breath method with age-adjusted exhalation times highly feasible for children aged 4-10 years. ICS-naïve asthmatic children had FeNO levels under the current guideline cutoff level (20 p.p.b.), highlighting the importance of taking age into account when setting reference values.
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| 9. |
- Heijkenskjöld Rentzhog, Charlotte, et al.
(författare)
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Overall and peripheral lung function assessment by spirometry and forced oscillation technique in relation to asthma diagnosis and control.
- 2017
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 47:12, s. 1546-1554
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Classic spirometry is effort dependent and of limited value in assessing small airways. Peripheral airway involvement, and relation to poor control, in asthma, has been highlighted recently. Forced oscillation technique (FOT) offers an effort-independent assessment of overall and peripheral lung mechanics. We studied the association between lung function variables, obtained either by spirometry or multifrequency (5, 11 and 19 Hz) FOT, and asthma diagnosis and control.METHODS: ), resistance difference between 5-19 Hz (R5-R19) and Asthma Control Test scores were determined in 234 asthmatic and 60 healthy subjects (aged 13-39 years). We used standardized lung function variables in logistic regression analyses, unadjusted and adjusted for age, height, gender and weight.RESULTS: and R5-R19) were associated with uncontrolled asthma (P-values < .05).CONCLUSIONS: /FVC, supporting a complementary role for FOT. Asthma control was related to FOT measures of peripheral airways, suggesting a potential use in identifying such involvement. Further studies are needed to determine a clinical value and relevant reference values in children, for the multifrequency FOT measurements.
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| 10. |
- Jacinto, Tiago, et al.
(författare)
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Differential effect of cigarette smoke exposure on exhaled nitric oxide and blood eosinophils in healthy and asthmatic individuals
- 2017
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Background:Tobacco smoking affects both the fraction of exhaled nitric oxide (FeNO) and blood eosinophil (B-Eos) count, two clinically useful biomarkers in respiratory disease that represent local and systemic type-2 inflammation, respectively.Objective:We aimed to study the influence of objectively measured smoke exposure on FeNO and B-Eos in a large population of subjects with and without asthma.Methods:We utilized the US National Health and Nutrition Examination Surveys 2007-2012 and included 10 669 subjects aged 6-80 years: 9869 controls and 800 asthmatics. Controls were defined as having no respiratory disease, no hay fever in the past year, and B-Eos count ≤0.3 × 109 l−1. Asthma was defined as self-reported current asthma and at least one episode of wheezing or an asthma attack in the past year, but no emphysema or chronic bronchitis. Tobacco use was collected via questionnaires and serum cotinine was measured with mass spectrometry.Results:Increasing cotinine levels were associated with a progressive reduction in FeNO in both controls and asthmatics. FeNO remained significantly higher in asthmatics than controls except in the highest cotinine decile, equivalent to an average reported consumption of 13 cigarettes/day. B-Eos count increased with cotinine in controls, but was unchanging in asthmatics. Interestingly, B-Eos count was significantly higher in presently non-exposed (cotinine below detection limit) former smokers than never smokers.Conclusion:Smoke exposure decreases FeNO and increases B-Eos count. These effects should be considered in the development of normalized values and their interpretation in clinical practice. The persistence of elevated B-Eos in former smokers warrants further studies.
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