Korean J Asthma Allergy Clin Immunol.  2012 Sep;32(3):159-168.

Change of Inflammatory Markers in Induced Sputum in Suspected Asthmatics by Asthma Treatment

Abstract

BACKGROUND
Eosinophilic airway inflammation is characteristic for typical asthma, but neutrophilic inflammation has been found in severe asthmatics resistant to steroid therapy. This study aimed to evaluate responses to asthma treatment according to inflammatory cell types in sputum.
METHODS
For a cross-sectional study, 240 consecutive patients with suspected asthma who underwent a 4.5% saline-induced sputum test and a test for airway hyperresponsiveness to methacholine or for airway reversibility were enrolled. Of these patients, 23 who inhaled corticosteroids were entered to a follow-up sputum study.
RESULTS
The number of sputum eosinophils was significantly related to the forced expiratory volume in one second/forced vital capacity (r=-0.180, P<0.05) and airway hyperresponsiveness (r=-0.222, P<0.01), and the number of neutrophils was significantly related to age (r=0.165, P<0.05) and forced expiratory volume in one second (r=-0.157, P<0.05). Subjects with sputum eosinophilia (n=88, 20.5%) had received asthma treatment before the tests more often than those with neutrophilia (n=23, 4.3%) or mixed granulocytic nature (n=11, 0%) (P<0.05 for each). In the follow-up study, the number of eosinophils was significantly decreased in the eosinophilic subjects (P<0.05), and the Deltainterferon-gamma/interleukin-5 ratio was significantly related to Deltaeosinophils (r=0.933, P<0.001). There was an inverse relationship between the number of neutrophils and the increase in forced expiratory volume in one second (r=-0.459, P<0.05) or Deltainterferon-gamma (r=-0.842, P<0.01).
CONCLUSION
The severity of asthma may depend on inflammatory cell types in sputum. Although inflammatory markers of sputum improve by asthma treatment, treatment responses differ according to cell types. Therefore, sputum examination may be useful for predicting therapeutic responses in asthmatics.

MeSH Terms

Adrenal Cortex Hormones
Asthma
Cross-Sectional Studies
Eosinophilia
Eosinophils
Follow-Up Studies
Forced Expiratory Volume
Humans
Inflammation
Methacholine Chloride
Neutrophils
Sputum
Vital Capacity
Adrenal Cortex Hormones
Methacholine Chloride