Introduction: The mechanism for adverse reactions to foods in the gastrointestinal tract are poorly understood. Previous studies of other atopic diseases and animal models suggest that lymphocytes and cytokines may be implicated in the pathogenesis of food allergy.
Aim: The authors investigated the expression of interleukin-4, interferon-gamma and other lymphocyte markers of patients with cereal allergy (wheat, rye, oats) and of controls.
Patients/method: Expressions of cytokines and lymphocyte markers on duodenal mucosa of nine patients (mean age 38.3 years, range 18-50 years, 8 women and one man) and nine controls (mean age 36 years, range 24-54 years, 6 women, 3 men) by means of immunohistochemistry were investigated.
Results: The mucosal structure on every biopsy specimens was normal. Despite the normal structure the expression of Ki-67 intranuclear proliferation marker was higher in patients with cereal allergy. Expression of interleukin-4 was markedly elevated in the food allergy group, however, interferon-gamma density showed no inter-group difference. The densities of CD4 (1251 vs. 1053 cells/mm2) and HLA-DR positive cells (1227 vs. 1064 cells/mm2) in the lamina propria of cereal allergy group were significantly elevated when compared with controls (P = 0.05 and P = 0.04, respectively). The densities of CD3, CD8, TCR alpha/beta and gamma/delta, HLA-DP, IgA, IgA1, IgA2-containing cells did not differ in the two groups studied.
Conclusions: The authors results suggest that, despite the normal mucosal structure, the increased expression of CD4 and HLA-DR positive cells show a sign of inflammation in duodenal biopsies of patients with cereal allergy. Moreover, increased density of IL-4 may suggest its role in the pathogenesis of cereal hypersensitivity.