Eosinophilic_Esophagitis_Pathophysiology_and_Surgical_Management

osinophilic Oesophagitis (EoE) is defined as a chronic, immune or antigen-mediated process characterised clinically by oesophageal dysfunction and pathologically by mucosal inflammation where eosinophils are the predominant cell type. Under normal physiological conditions, the oesophagus lacks eosinophils; their presence indicates a pathological state in response to various stimuli or antigens.Etiology of EoEThe precise etiology of EoE remains unknown, but it is currently understood to be the result of complex interactions between environmental, genetic, and host immune factors.

• • Allergic and Atopic Links: There is a robust correlation between EoE and atopy. Patients frequently have a history of asthma, atopic dermatitis, chronic seasonal allergies, or other immunologic conditions. While food allergies are a common trigger, food-related anaphylaxis is rarely observed in these patients.
  • Genetic Component: The condition has a strong genetic basis, evidenced by a high concordance of the disease among family members. Research into the genome-wide microarray expression profile identified the TSLP (thymic stromal lymphopoietin) gene, located on the 5q22 region of the male X chromosome, as a key factor.

1. • Th2 Cell Activation: The TSLP gene stimulates Th2 cells and induces the expression of eotaxin-3, which is notably overexpressed in the oesophageal mucosa of EoE patients.
   • Cytokine Recruitment: Stimulated Th2 cells activate various proinflammatory cytokines, specifically IL5, IL13, and IL15. These cytokines are responsible for the recruitment of eosinophils to the oesophageal tissue.
   • Antigen Exposure: Interestingly, it is reported that even a single exposure to a cutaneous or airway antigen challenge can trigger the recruitment of eosinophils to the oesophagus.

• • Fibrosis and Dysfunction: TGF-B is responsible for the remodelling of the oesophageal mucosa and smooth muscle dysfunction.
  • Chronic Changes: Repeated exposure to antigens leads to chronic inflammation, which eventually results in fibrosis and structural changes such as strictures, fixed rings (trachealisation), and a narrow lumen.
  • Symptomatic Manifestation: These structural changes clinically manifest as dysphagia (difficulty swallowing), chest pain, and food impaction, which is the most common emergency presentation for adults with the condition

Pathophysiology and Immunogenic MechanismsThe pathophysiology of EoE involves an overactive immunogenic reaction to antigens found in food and air. This process transforms the oesophagus into an active immunogenic organ through the following steps:Tissue Remodelling and Clinical ProgressionA critical aspect of EoE pathophysiology is the role of TGF-B (transforming growth factor-beta). This cytokine is released by the recruited eosinophils and mast cells.