Interrelation Between Bronchial Asthma and Smoking
Condition: Bronchial Asthma
MeSH terms: Asthma
Study type: Observational

Summary: 
      Smoking occurs frequently in patients with asthma. Recent surveys on smoking prevalence
      report 21-26% current smokers in populations of patients with asthma. Detrimental effects of
      active smoking in asthma include worse asthma control, an impaired response to
      corticosteroids and accelerated lung function decline.
    

Detailed description: 
      The mechanisms by which cigarette smoking contributes to disease severity in asthma are
      incompletely understood, but it has been suggested that cigarette smoking may change
      inflammation and airway remodelling in asthma to become more similar to that in COPD (chronic
      obstructive pulmonary disease).

      Any form of tobacco use, especially cigarette smoking, plays an important role in this
      disease. Asthmatic smokers are prone to several negative outcomes. Cigarette smoking by
      itself is associated with airway inflammation and features of airway remodelling including
      increased epithelial proliferation, squamous cell metaplasia, goblet cell hyperplasia, smooth
      muscle hypertrophy, and increases in bronchial glands mass.

      Corticosteroid insensitivity is an important clinical feature of asthma, particularly in
      patients with severe disease and smokers. The mechanisms of corticosteroid insensitivity in
      asthmatic patients are poorly understood.

      One of the major problems in the treatment of smoking asthma patients is the lack of efficacy
      data in this group of patients as smokers have almost always been excluded from studies on
      asthma due to perceived concerns about recruiting patients with COPD. Therefore, there is a
      lack of specific information about the treatment of asthma in smokers. The asthmatic smoker
      is a special phenotype with important therapeutic and prognostic clinical implications.
    

Intervention name(s): using serum periostin and eotaxin-2 level; airway corticosteroid sensitivity
Intervention type(s): Diagnostic Test; Diagnostic Test
Intervention description(s): collect serum sample from each group and detection of serum periostin and eotaxin-2 are using Eliza kits.
each group is divided into two groups (patients who are already using ICS and patients who do not use ICS) and we compare between to groups in airway hypersensitivity.; each group is divided into two groups (patients who are already using inhaled corticosteroid ICS and patients who do not use ICS) and we compare between to groups in airway hypersensitivity.
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Stable asthmatic patients (however smokers, or non-smokers) will be included (stable
        asthmatic defined as no emergency clinic or hospital visit, oral corticosteroid
        prescription, or change in asthma treatment in the past month) and (Current smoking was
        defined as 5 or more cigarettes per day and a smoking history of 5 pack years or greater).
      
Biospecimen description: 
      sputum and serum sample