Corticosteroid resistance in eosinophilic gastritis--relation to in vitro eosinophil survival and interleukin 5

Eosinophilic gastritis is usually responsive to corticosteroid therapy. In some cases, large doses and protracted treatment are required. This report describes a case of eosinophilic gastritis that was partially corticosteroid resistant. To determine mechanisms that explain this patient's incomplete response to corticosteroid therapy, peripheral blood eosinophils and serum were isolated from the patient. We found the in vitro survival of the patient's eosinophils was prolonged. In addition, his serum both promoted in vitro eosinophil survival and nullified the survival inhibiting of effect of hydrocortisone (10 microM). Furthermore, antibody against interleukin 5 (IL5) partially inhibited the enhanced eosinophil survival produced by the patient's serum and completely blocked the decrease in survival resulting from hydrocortisone. These observations indicate that elevated circulating levels of IL5 may contribute to the peripheral eosinophilia and corticosteroid resistance in some patients with eosinophilic gastritis.