lecture 13

• what are obstructive lung diseases?

  CODP, asthma, cystic fibrosis
• what is a restrictive lung disease?

  pulmonary fibrosis
• what is obstructive lung disease?

  conditions that make it hard to exhale all the air from the lungs and makes it harder to breathe, especially during increased activity or exertion.
• what is restrictive lung disease?

  difficult time filling their lungs with air. This can be a result of the lungs being restricted from fully expanding
• CODP is a common, preventable and treatable disease, characterized by persistent respiratory symptoms and airflow limitation that is usually progressive, and is associated with an enhanced chronic inflammatory response in the airways and lungs.
• what are the classification of COPD?

  Emphysema, chronic bronchitis, small airway disease
• Chronic bronchitis:

  • involves inflammation of the airways
  • enlarged submucosal gland (hypertrophy), inflammation of epithelium, mucous accumulation.
  • air tubes narrow as a result of swollen tissue and excessive mucous production.
• how do you diagnose chronic bronchitis?

  Mucus production leading to cough for 3 consecutive months in at least 2 consecutive years
• emphysema:

  • involves Irreversible destruction of alveolar structures
  • Permanent airspace enlargement distal to terminal bronchioles
• small airways disease:

  • involves the remodeling lung structures
  • fibrosis, mucous plug, increased number of goblet cells, more inflammatory cells
• COPD is also associated with: Exacerbations that contribute to the overall severity in individual patients
• what is an exacerbation? how is it caused?

  An acute event characterized by a worsening of the patient’s respiratory symptoms that is beyond normal day-to-day variations. Increased (worsening) cough, dyspnea, production of sputum. Frequently caused by infections.
• Other than exacerbations, CODP is associated with co-morbidities.
• what is a co-morbidity?

  Presence of two or more medical conditions in a patient.
• what are some co-morbidities of COPD?

  Cardiovascular disease

  Lung cancer

  Osteoporosis

  Skeletal muscle dysfunction

  Anxiety/depression

  Metabolic syndrome/disorders

  Diabetes
• what are risk factors of COPD?

  cigarettes, genes, age (40+), air pollution, occupational dust and chemicals
• what gene is associated with COPD? How so?

  Alpha-1 antitrypsin - it inhibits neutrophil elastase, which is an elastolytic enzyme that can degrade lung architecture, so if there is a deficiency, it can cause COPD.
• why is smoking a risk factor for COPD?

  since it can cause an inflammatory response, which is associated with chronic bronchitis
• what are symptoms of COPD?

  Shortness of breath, chronic cough, sputum
• how do you diagnose COPD?

  using spirometry to find FEV1 /FVC (asses airflow limitation) and if less than 0.7, then there is a limitiation.
• what is GOLD?

  classification of severity of airway obstruction
• what is asthma?

  Asthma is a heterogeneous disease, usually characterized by chronic inflammation and a variable expiratory airflow limitation.
• what is the hallmark of asthma?

  reversible airway obstruction
• what are the two categories of asthma?

  atopic and non-atopic
• what are the risk factors of atopic asthma?

  pollen, pets, dustmites
• what are risk factors of non-atopic asthma?

  chemicals, cleaning agent, air freshener, exercise, cigarette smoke, pollution, hot/cold weather, laughter, stress
• Atopic (allergic, extrinsic):

  • Evidence of allergic sensitization
  • Often in a patient with a history of allergic rhinitis or eczema
  • Common
  • Family history common
  • onset: childhood
• Non-atopic (non-allergic, intrinsic):

  • Not caused by exposure to an allergen
  • Common triggers are viruses and inhaled pollutants
  • Family history uncommon
  • onset: adult (more common in women)
• Asthma pathology:

  • narrowed airway
  • tightened muscles constrict airways (hyperplasia and hypertrophy)
  • inflamed/thickened airway wall
  • mucous (increase volume of submucosal glands)
  • increased number of blood vessels
  • fibrosis
• Th2 causes release of what mediators?

  IL-4, IL-5, IL-13, IL-9
• what does IL-4 do?

  stimulates B cells specific for the antigen to produce IgE
• what does IL-5 do?

  mobilizes and activates eosinophils
• what does IL-13?

  stimulates mucus secretion and goblet cell hyperplasia
• what does IL-9 do?

  Eosinophil survival; B cell class switch
• what do eosinophils do in asthma?

  release factors that cause airway hyperresponsiveness, mucous production, tissue damage, and airway remodeling.
• what is a cardinal feature of asthma?

  airway hyperresponsiveness
• what causes the day-to-day symptoms of asthma?

  Airway Hyperresponsiveness
• what is Airway Hyperresponsiveness?

  the predisposition of the airways to narrow excessively in response to stimuli (histamine and methacholine) that would produce little or no effect in healthy subjects -- exaggerated bronchoconstriction.
• what is used to diagnose asthma?

  Bronchial provocation test, which measures the PC20 (Provocative concentration causing a 20% fall in FEV1). If it is more than 16 mg/ml then it is normal, but of it is less than 8 mg/ml then there is asthma
• what is the treatment of asthma?

  corticosteroid inhaled alone or with beta 2 agonist