Asthma

Intrinsic Asthma

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Intrinsic Asthma, Non-allergic Asthma, Non-Type 2 Asthma, Non-T2 Asthma, Late Onset Asthma, T2 Low Asthma, Neutrophilic Asthma

  • See Also
  1. Asthma
  2. Extrinsic Asthma (Allergic Asthma)
  3. Asthma Evaluation
  4. Asthma Differential Diagnosis
  5. Asthma Management
  6. Asthma Exacerbation
  • Epidemiology
  1. Much more common in adults than children
  2. Onset age over 40 years old
  • Pathophysiology
  1. Non-IgE, Non-allergic Asthma
  2. Neutrophil mediated Asthma
  1. Neutrophilic Asthma (adult onset, non-atopic)
    1. May be paucigranulocytic or Neutrophilic
    2. Biomarkers include NLRP3/IL-1b and Th17, MMP-9
  2. Obesity Associated (esp. female)
    1. Mediators include oxidative stress, Neutrophil activity, activation of Innate Immunity
    2. Biomarkers include Serum IL-6
    3. Associated with severe symptoms despite preserved lung function
  3. Smoking Associated
    1. Typically occurs in older adults, with frequent exacerbations and reduced lung function testing
    2. Differentiate from COPD (or both may be present)
    3. Induced Sputum with increased Neutrophils (see labs below)
    4. Mediators include oxidative stress as well as mixed Th2 high and Th2 low activity
  4. Very Late Onset Asthma (age >50 or >65 years)
    1. Often steroid resistant
    2. Induced Sputum with increased Neutrophils (see labs below)
    3. Mediators include immunosenescence and Th1/Th7 inflammation
  • Risk Factors
  1. Irritant exposure (esp. Tobacco Smoking)
    1. Air Pollution
    2. Fumes
    3. Perfumes
    4. Household cleaning agents
    5. Insecticides
    6. Fresh paint
    7. Tobacco Smoking or Secondhand Smoke
    8. Cold air
  2. Infection
    1. Upper Respiratory Infection
    2. Purulent Rhinitis
    3. Acute Sinusitis
  3. Gastroesophageal Reflux
  4. Medications
    1. Beta Blockers (even Intraocular Beta Blocker)
  5. Body Habitus
    1. Obesity
  • Findings
  • Symptoms and Signs
  1. See Asthma Evaluation
  • Labs
  • Markers
  1. Neutrophilia
    1. Sputum Neutrophils >40 to 60%
  2. Cytokines (experimental)
    1. Interleukins (IL-6, IL-8, IL-17)
    2. Adipokine (Obesity)
  • Management
  1. See Asthma Management
  2. See Asthma Exacerbation
  • References
  1. Kuruvilla (2019) Clin Rev Allergy Immunol 56(2):219-33 +PMID: 30206782 [PubMed]