Prevalence of Bronchiectasis in Asthma according to Oral Steroid Requirement: Influence of Immunoglobulin Levels

Manel Luján,Christian Domingo,Xavier Gallardo,María José Amengual,Rosa M Mirapeix,Montserrat Bosque

doi:10.1155/2013/109219

Abstract

Purpose. To establish the prevalence of bronchiectasis in asthma in relation to patients' oral corticosteroid requirements and to explore whether the increased risk is due to blood immunoglobulin (Ig) concentration. Methods. Case-control cross-sectional study, including 100 sex- and age-matched patients, 50 with non-steroid-dependent asthma (NSDA) and 50 with steroid-dependent asthma (SDA). Study protocol: (a) measurement of Ig and gG subclass concentration; (b) forced spirometry; and (c) high-resolution thoracic computed tomography. When bronchiectasis was detected, a specific etiological protocol was applied to establish its etiology. Results. The overall prevalence of bronchiectasis was 12/50 in the SDA group and 6/50 in the NSDA group (p = ns). The etiology was documented in six patients (four NSDA and two SDA). After excluding these patients, the prevalence of bronchiectasis was 20% (10/50) in the SDA group and 2/50 (4%) in the NSDA group (P < 0.05). Patients with asthma-associated bronchiectasis presented lower FEV1 values than patients without bronchiectasis, but the levels of Ig and subclasses of IgG did not present differences. Conclusions. Steroid-dependent asthma seems to be associated with a greater risk of developing bronchiectasis than non-steroid-dependent asthma. This is probably due to the disease itself rather than to other influencing factors such as immunoglobulin levels.

Highlights

Bronchiectasis is defined as abnormal, irreversible thickwalled dilatation of the bronchi and represents the end stage of a variety of pathological processes
The majority of identified causes of BioMed Research International bronchiectasis are infections (24% [2, 3] and 29% [4]), associations have been reported with new entities like adulthood cystic fibrosis [5, 6], humoral immunodeficiency including common variable immunodeficiency [7, 8], and systemic diseases [9]
The aim of the present study was to compare the prevalence of bronchiectasis in a cohort of patients with severe steroid-dependent asthma (SDA) and in another with nonsteroid-dependent asthma (NSDA), in order to establish whether the SDA group has an increased associated risk of developing bronchiectasis

Summary

Introduction

Bronchiectasis is defined as abnormal, irreversible thickwalled dilatation of the bronchi and represents the end stage of a variety of pathological processes. Caused by the inflammatory reaction of the bronchi and their frequent chronic bacterial colonization, bronchiectasis usually presents with recurrent lower respiratory tract infections and chronic mucopurulent sputum production. In a recent study the etiology of the condition was identified in only 57% of patients [1]. The majority of identified causes of BioMed Research International bronchiectasis are infections (24% [2, 3] and 29% [4]), associations have been reported with new entities like adulthood cystic fibrosis [5, 6], humoral immunodeficiency including common variable immunodeficiency [7, 8], and systemic diseases [9]. Today, the etiology is identified in fewer than 50% of patients with the condition [4, 11]

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