Eosinophilic Disorders - eMBP

Eosinophilic Disorders - eMBP

 

Eosinophil-associated disease occurs in all epithelial organs including the skin, upper and lower respiratory tract, gastrointestinal tract, urinary tract and the heart.

Pathophysiology

  • Eosinophilic activity
    • Eosinophil activity is associated with allergies, parasitic diseases, multiple inflammatory diseases of epithelial organs and neoplastic disease
  • Eosinophil Major Basic Protein (eMBP)
    • Eosinophil major basic protein is a cationic protein that is toxic to mammalian cells and tissues
    • Extracellular eMBP in tissues represents eosinophil activity in the presence or absence of intact eosinophils
    • Many diseases with eosinophil association, including eczematoid, urticarial, angioedema, vasculitis, blistering, fibrosis, airway inflammation, gastrointestinal inflammation, eosinophilic cystitis
  • Two disease processes in which eMBP analysis is an example of its usefulness are eosinophilic vasculitis and eosinophilic esophagitis
    • Eosinophilic vasculitis
      • Eosinophilic vasculitis is a disorder that involves eosinophilic infiltration of small blood vessels
        • Incidence – rare
        • Risk Factors
          • Connective tissue disease
          • Parasitic infection
          • Hypereosinophilic syndrome
          • Eosinophilic panniculitis
          • Temporal arteritis (very rare)
        • Clinical Presentation
          • Pruritus
          • Erythematous purpuric plaques
          • Angioedema
        • Diagnosis
          • Complete blood count with differential
          • Immunofluorescence of biopsy
            • Angiocentric eMBP staining
            • Decreased mast tryptase staining
        • Treatment – glucocorticoids
    • Eosinophilic esophagitis
      • Eosinophilic esophagitis (EE) is characterized by eosinophilic infiltration of the epithelium of the esophagus
        • Incidence – uncommon, but has increased dramatically over the last 10 years
        • Age – childhood to elderly, often diagnosed in 3rd decade but earlier diagnosis recently because of awareness
        • Gender – M>F
        • Risk Factors
          • Positive family history
          • History of severe food allergies
        • Clinical Presentation
          • Children <2 years old – feeding disorders
          • Children 2-12 – emesis, abdominal pain
          • >12 years old – dysphagia, esophageal food impaction
        • Diagnosis
          • eMBP in esophageal tissue
          • Eosinophilic infiltration of esophageal squamous epithelium >20 eosinophils per high-powered field
        • Treatment
          • Elimination diets
          • Glucocorticoids

See Also