Interleukin-5 immunoreactivity and mRNA expression in gut mucosa from patients with food allergy

Clin Exp Allergy. 1999 May;29(5):652-9. doi: 10.1046/j.1365-2222.1999.00511.x.


Background and aims: Eosinophils, mast cells and T lymphocytes are important cells in the allergic inflammatory process. These cells produce and are regulated by cytokines such as interleukin-3 (IL-3), interleukin-5 (IL-5) and granulocyte macrophage-colony stimulating factor (GM-CSF). We initiated this study to evaluate pathological abnormalities and to detect IL-5 in the duodenal mucosa from patients with food allergy.

Methods: Endoscopy duodenal biopsy specimens were obtained from seven food-allergic patients, six atopic healthy controls and six nonatopic healthy controls. IL-5 protein was evaluated by immunohistochemistry. Electron microscopy as well as double immunofluorescent staining were used to identify the labelled cells and to localize IL-5. IL-5 mRNA expression was evaluated by qualitative polymerase chain reaction.

Results: A significantly increased number of lymphocytes, mast cells and eosinophils was detected in the lamina propria in food-allergic patients and, in lower number, in atopic controls. Immunostaining for IL-5 was markedly positive in food-allergic patients, slightly increased in atopic controls and negative in nonatopic controls. Ultrastructurally, in food-allergic patients and in atopic controls, IL-5 was localized in eosinophil granules, in the matrix of intact granules and at the periphery of altered granules. Double immunofluorescent staining was performed in food-allergic patients and showed that 86.7% of IL-5+ cells were eosinophils, and that IL-5 was expressed by 24% of eosinophils. IL-5 mRNA was expressed in food-allergic patients but was not detected in atopic and nonatopic controls.

Conclusion: Activated eosinophils are involved in gut atopic reactions occurring in food allergy and are probably in part upregulated by their own local production of IL-5.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Cytoplasmic Granules / immunology
  • Cytoplasmic Granules / ultrastructure
  • Duodenum / immunology
  • Duodenum / ultrastructure
  • Eosinophils / immunology*
  • Eosinophils / ultrastructure
  • Female
  • Fluorescent Antibody Technique
  • Food Hypersensitivity / immunology*
  • Food Hypersensitivity / pathology
  • Humans
  • Hypersensitivity, Immediate / immunology
  • Immunohistochemistry
  • Interleukin-5 / analysis*
  • Interleukin-5 / biosynthesis
  • Interleukin-5 / immunology
  • Intestinal Mucosa / immunology*
  • Intestinal Mucosa / ultrastructure
  • Male
  • Microscopy, Electron
  • Middle Aged
  • Polymerase Chain Reaction
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism


  • Interleukin-5
  • RNA, Messenger