SELECTED ARTICLES FROM THE RECENT LITERATURE 2005

8/10/05

Treatment of eosinophilic G-I disorders

Summary
Background - There has been an increasing recognition of a variety of G-I disorders characterized by marked local eosinophilic inflammation (E-GID). The treatment of these conditions has been the subject of considerable investigation.

Findings - The treatment of E-GID was reviewed by Foroughi and Pussin of the Laboratory of Allergic Diseases, NIAID, NIH. The pointed out that corticosteroids (CS) are effective in many cases of E-GID; however, sustained use of CS is often needed with an attendant risk of adverse effects. They described their management approaches including trials of anti-IgE and anti-IL5 antibodies in E-GID, mostly in adults with eosinophilic gastroenteritis (EG) with/without eosinophilic esophagitis (EE). Systemic and topical CS - almost all of their patients responded to systemic CS, such as 20-40 mg prednisone/day for 2-6 weeks. More effective than intermittent "burst" courses of 7 days. The CS dose is then tapered to the lowest amount required for control, aiming for alternate day therapy. Trials of topical CS such as orally administered fluticasone (440 microg b.i.d.) or budesonide have given promising results. Repeated endoscopies may be needed to assess whether eosinophilic inflammation is reduced and whether or not secondary fibrosis in imvolved areas has occurred. Reduction of food allergies (found in about 50% of E-GID cases) by elimination diets may be very helpful. In some cases where multiple food allergies are present, an elemental diet may be needed for awhile. If concomitant GERD is found, treatment with proton pump inhibitors may be helpful.

They have found marked reduction of blood and tissue eosinophilia but no decrease in G-I symptoms during anti-IL5 therapy of E-GID. It is still too early to draw conclusions about effect of anti-IgE therapy in these disorders.

Many patients with E-GID have iron deficiency anemia, and possibly protein malabsorption with secondary anemia. Iron replacement is frequently needed.Osteopenia/osteoporosis are among the most common adverse effects of long-term chronic CS therapy in E-GID. A baseline DEXA scan should be obtained when starting CS therapy and treatment with supplemental calcium/vitamin D2 added. If there is evidence of osteoporosis on the DEXA, bisphosphonate therapy should be considered. If EE is present, alendronate (Foxamax) should be avoided because of the potential for irritation of the esophagus by this drug. Instead, one should use one weekly risedronate (Actonel) or possibly once yearly zoledronate given IV.

Reference
 Curr Allergy and Asthma Reports 2005;5:259-61

Editor's Comments
These management approaches are well described and worth consideration in a group of disorders being diagnosed with increasing frequency. The lack of symptomatic improvement with anti-IL5 therapy despite marked decreases in G-I tissue eosinophilia raises questions about the pathogenic role of eosinophils in E-GID.

 

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