Eosinophilic gastro-intestinal diseases (EGID) can affect the gastro-intestinal tract from the esophagus to the colon and is often associated to atopy in eosinophilic esophagitis. Proximal esophageal inflammation is of better prognosis than distal eosinophilic infiltrations (colon) that can evolve to hypereosinophilic syndrome. Interleukin-5 is a major stimulus in eosinophil recruitment to the gastro-intestinal tract as well as to the lungs. That was the rationale to initiate clinical trials with a monoclonal anti-IL-5 antibody in patients with asthma. Whereas treatment was ineffective on bronchial hyperreactivity and weakly inhibited eosinophil infiltrates, therapy with anti-IL-5 mAb resulted in a significant decrease in extracellular matrix deposition, suggesting a role for anti-IL-5 mAb in limiting bronchial remodeling.