12 2023 asthma lecture

Please do not use homatropine-containing cough medication (atropine or other "drying" agents for mucus in CF patients can cause inspissation of mucus in the smaller airways and exacerbate CF and cause PNA.

Pathophysiology

  • APC stimulates CD4 T cells that can be either TH1 or TH2, which are both type 4 hypersensitivity
  • IL4 leads to TH2 activation and then IL4, 5, 13. This goes down the humoral immunity/allergy profile and elevated eosinophils and IgE
  • IL12 leads to TH1 activation and then IFNY and TNF alpha. This leads to cellular immunity and alveolar macrophage/granuloma formation
  • TH17 cells leads to neutrophil activation

Asthma has 2 forms

  • childhood: allergy, atopy
  • adult: TH2 high vs TH2 low, AKA allergic vs nonallergic
  • There's also difference between chronic inflammation (Type 4 HSR) vs acute exacerbation (T1 HSR, IgE cross link, histamine, mast cell activation, TH2 activation, eos, baso, neutrophil)
  • In early phase, you can treat with ICS and bronchodilators. In late phase you have to use steroids

ABPA

  • like asthma
  • type 4 TH2 HSR
  • antigen: aspergillus fumigatus
  • finger in glove bronchiectasis

HP

  • HP: TH1 disease
  • repeat exposure to organic Ag
  • acute, subacute (weightloss, fatigue), chronic (fibrotic
  • PFT: can be normal or restrictive
  • Acute: granulomas and lymnphocytic inflammation
  • Chronic: fibrotic but without a lot of honeycombing
  • CD4/CD8 < 1 (high CD8 count), different from sarcoid > 1
  • HP panel: IgG antibodies to antigen

GPA

  • cell mediated response
  • sinus + lung + renal
  • pulmonary lesions can be cavitary because of necrosis
  • airway obstruction: destruction of airway cartilege

EGPA

  • always asthma + allergic rhinitis
  • vasculitis
  • allergic granulomatosis
  • can have mass like lesions
  • extrapulmonary sx: mononeurits multiplex
  • heart disease: myocarditis
  • P-ANCA
  • tissue eosinophilia
  • TH2: granulomas of eosinophils.
  • Charcot leiden crystals
  • Treatment: glucocorticoids, IL5 inhibitors like mepolizumab, rituxan

Sarcoid

  • BHC, lupus pernio, logen syndrome
  • TH1

CGD

childhood disease

x-linked

resource: https://www.amazon.com/Practical-Pulmonary-Pathology-Diagnostic-Recognition/dp/1416057706