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Kinetics of TH2 biomarkers in sputum of asthmatics following inhaled allergen.

Zuiker RG, Ruddy MK, Morelli N, Mogg R, Rivas VM, van Dyck K, De Lepeleire I, Tanen MR, Boot JD, Kamerling IM, Diamant Z - Eur Clin Respir J (2015)

Bottom Line: Allergen-induced changes in inflammatory endpoints were compared between FP and placebo using a mixed model ANCOVA.FP effectively blunted both the LAR and the inflammatory biomarkers.This approach allows non-invasive identification of pharmacodynamic targets for anti-asthma therapies.

View Article: PubMed Central - PubMed

Affiliation: Centre for Human Drug Research, Leiden, The Netherlands.

ABSTRACT

Background: Allergen-induced late airway response offers important pharmacodynamic targets, including T helper 2 (TH2) biomarkers. However, detection of inflammatory markers has been limited in dithiothreitol-processed sputum.

Objectives: To test whether allergen-induced TH2 inflammatory markers can be reproducibly quantified by sensitive detection techniques in ultracentrifuged sputum and the effect of fluticasone (FP) on these endpoints.

Methods: Thirteen allergic asthmatics with dual allergen-induced airway responses, documented during a single-blind placebo run-in period, participated in a double-blind, two-period crossover study. Each period consisted of three consecutive days, separated by ≥3 weeks. Following randomization, subjects inhaled FP (500 µg bid, five doses total) or placebo. On Day 2 in each study period, allergen challenge was performed and airway response measured by forced expiratory volume in 1 sec (FEV1) until 7 h post-challenge. Sputum was induced 24 h pre-allergen and 7 and 24 h post-allergen. Sputum samples were split into two portions: TH2 biomarkers were quantified by Meso Scale multiplex platform following ultracentrifugation, and cell differentials were counted on Giemsa-May-Grünwald-stained cytospins. Allergen-induced changes in inflammatory endpoints were compared between FP and placebo using a mixed model ANCOVA.

Results: Inhaled allergen induced dual airway responses in all subjects during both placebo periods with reproducible late asthmatic response (LAR) and increased sputum inflammatory biomarkers (IL-2, IL-4, IL-13, and eotaxin-1) and eosinophil counts. FP effectively blunted both the LAR and the inflammatory biomarkers.

Conclusions: Combining novel, sensitive quantification methods with ultracentrifugation allows reproducible quantification of sputum biomarkers following allergen challenge, reversed by FP. This approach allows non-invasive identification of pharmacodynamic targets for anti-asthma therapies.

No MeSH data available.


Related in: MedlinePlus

Time-response curves (mean±SEM) to inhaled allergen during run-in period, placebo treatment, and fluticasone treatment.
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Figure 0003: Time-response curves (mean±SEM) to inhaled allergen during run-in period, placebo treatment, and fluticasone treatment.

Mentions: Inhaled HDM induced both an EAR and an LAR in all subjects during both placebo periods. Compared to placebo, FP significantly reduced the EAR and completely blunted the LAR (Fig. 3). The reproducibility of the allergen-induced LAR during both placebo periods was good, both in terms of the maximum percent fall in FEV1 from baseline and as time-weighted average (3–7 h post-allergen), with an ICC of 79.7 and 69%, respectively (Table 2).


Kinetics of TH2 biomarkers in sputum of asthmatics following inhaled allergen.

Zuiker RG, Ruddy MK, Morelli N, Mogg R, Rivas VM, van Dyck K, De Lepeleire I, Tanen MR, Boot JD, Kamerling IM, Diamant Z - Eur Clin Respir J (2015)

Time-response curves (mean±SEM) to inhaled allergen during run-in period, placebo treatment, and fluticasone treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4629766&req=5

Figure 0003: Time-response curves (mean±SEM) to inhaled allergen during run-in period, placebo treatment, and fluticasone treatment.
Mentions: Inhaled HDM induced both an EAR and an LAR in all subjects during both placebo periods. Compared to placebo, FP significantly reduced the EAR and completely blunted the LAR (Fig. 3). The reproducibility of the allergen-induced LAR during both placebo periods was good, both in terms of the maximum percent fall in FEV1 from baseline and as time-weighted average (3–7 h post-allergen), with an ICC of 79.7 and 69%, respectively (Table 2).

Bottom Line: Allergen-induced changes in inflammatory endpoints were compared between FP and placebo using a mixed model ANCOVA.FP effectively blunted both the LAR and the inflammatory biomarkers.This approach allows non-invasive identification of pharmacodynamic targets for anti-asthma therapies.

View Article: PubMed Central - PubMed

Affiliation: Centre for Human Drug Research, Leiden, The Netherlands.

ABSTRACT

Background: Allergen-induced late airway response offers important pharmacodynamic targets, including T helper 2 (TH2) biomarkers. However, detection of inflammatory markers has been limited in dithiothreitol-processed sputum.

Objectives: To test whether allergen-induced TH2 inflammatory markers can be reproducibly quantified by sensitive detection techniques in ultracentrifuged sputum and the effect of fluticasone (FP) on these endpoints.

Methods: Thirteen allergic asthmatics with dual allergen-induced airway responses, documented during a single-blind placebo run-in period, participated in a double-blind, two-period crossover study. Each period consisted of three consecutive days, separated by ≥3 weeks. Following randomization, subjects inhaled FP (500 µg bid, five doses total) or placebo. On Day 2 in each study period, allergen challenge was performed and airway response measured by forced expiratory volume in 1 sec (FEV1) until 7 h post-challenge. Sputum was induced 24 h pre-allergen and 7 and 24 h post-allergen. Sputum samples were split into two portions: TH2 biomarkers were quantified by Meso Scale multiplex platform following ultracentrifugation, and cell differentials were counted on Giemsa-May-Grünwald-stained cytospins. Allergen-induced changes in inflammatory endpoints were compared between FP and placebo using a mixed model ANCOVA.

Results: Inhaled allergen induced dual airway responses in all subjects during both placebo periods with reproducible late asthmatic response (LAR) and increased sputum inflammatory biomarkers (IL-2, IL-4, IL-13, and eotaxin-1) and eosinophil counts. FP effectively blunted both the LAR and the inflammatory biomarkers.

Conclusions: Combining novel, sensitive quantification methods with ultracentrifugation allows reproducible quantification of sputum biomarkers following allergen challenge, reversed by FP. This approach allows non-invasive identification of pharmacodynamic targets for anti-asthma therapies.

No MeSH data available.


Related in: MedlinePlus