0
Allergy and Airway |

Sputum Inflammatory Phenotype of Exacerbation-Prone Severe Asthma Patients- A Pilot Study

Shera Tan, MBBS; Carrie Leong, MBBS; Angela Takano; Therese Lapperre, MD; Keng Leong Tan, MBBS; Philine Chan; Kah Ling Lim; Mariko Koh, MBBS
Author and Funding Information

Singapore General Hospital, Singapore, Singapore


Chest. 2015;148(4_MeetingAbstracts):5A. doi:10.1378/chest.2264349
Text Size: A A A
Published online

Abstract

SESSION TITLE: Allergy and Airway Poster Discussions

SESSION TYPE: Original Investigation Poster Discussion

PRESENTED ON: Wednesday, October 28, 2015 at 08:45 AM - 10:00 AM

PURPOSE: Severe asthma is a heterogenous disease. Current management of severe asthma is moving towards targeted treatment addressing the mechanism of disease including inflammation. This study aims to examine the sputum inflammatory phenotype of severe asthmatics who are exacerbation-prone.

METHODS: Cross sectional study of patients with severe treatment- resistant asthma (on a combination of high-dose inhaled corticosteroids and long-acting beta agonists) and frequent exacerbations (≥2 exacerbations requiring systemic corticosteroids in the past year) was performed. Sputum induction was performed using a validated protocol. Demographic data, sputum inflammatory cell counts, spirometry, methacholine challenge test results and blood eosinophil levels were obtained. Sputum cell counts were read by an investigator blinded to clinical phenotype of the patient. The cell counts were classified into 4 groups: eosinophilic (>3%), neutrophilic (>76%), paucigranulocytic (normal levels of both eosinophils and neutrophils) and mixed (more than 1 predominant cell type present).

RESULTS: 8 Patients were recruited. 3 patients could not expectorate any sputum despite induction. The results of 5 successful patients (3 males, 2 females) are presented. Mean age was 48 ±11.2 years and median number of controllers used was 2 (IQR: 2-4). They had an average of 4 ± 1.5 exacerbations in the past year and the mean post-bronchodilator FEV1 was 2.50 ± 0.65L (85.8±9.9% predicted). The median blood eosinophil count was 0.44 x 109/L (IQR: 0.37-0.67 x 109/L). 3 patients had a predominantly eosinophilic inflammatory phenotype, whilst 2 had a paucigranulocytic inflammatory phenotype. The median eosinophil count from induced sputum was 6.00% (IQR: 0.8- 15.7%) and median neutrophil count was 12.2% (IQR: 4.8-12.7%).

CONCLUSIONS: Preliminary results seem to suggest more eosinophilic inflammation in the sputum of frequent exacerbating severe treatment-resistant asthmatics. None of the patients examined had neutrophilic inflammation in their sputum.

CLINICAL IMPLICATIONS: Treatment targeting eosinophils and the Th2 pathway may be the key to reducing exacerbations amongst some of these patients with frequent exacerbations. Lack of sputum production and paucigranulocytic picture suggest airway inflammation may not be the main mechanism driving exacerbations in the other group of frequent exacerbators. Further studies are underway.

DISCLOSURE: The following authors have nothing to disclose: Shera Tan, Carrie Leong, Angela Takano, Therese Lapperre, Keng Leong Tan, Philine Chan, Kah Ling Lim, Mariko Koh

No Product/Research Disclosure Information


Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Figures

Tables

References

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Find Similar Articles
CHEST Journal Articles
PubMed Articles
Characterization of sputum biomarkers for asthma-COPD overlap syndrome. Int J Chron Obstruct Pulmon Dis 2016;11():2457-2465.
Role of sputum biomarkers in the management of asthma. Curr Opin Pulm Med Published online Nov 4, 2016;
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543