Abstract: The objective of this work is to explore the correlation of serum cytokines in guinea pigs with food allergy and to deduce the impact of food allergy on the type 1/type 2 T-helper (Th1/Th2) cell balance. Mouse models of food allergy were induced by Pacific white shrimp (Litopenaeus vannamei) products with reduced allergenicity, shelled shrimp, shrimp meat and shrimp protein. Phosphate buffer (pH 7.5) was used as the negative control, and untreated shrimp protein was used as the positive control. Serum was collected from the allergic guinea pigs for the detection of immunoglobulin E (IgE), histamine (HIS) and cytokines (interleukin (IL)-1, IL-2, IL-3, IL-4, IL-6, IL-10, tumor necrosis factor α (TNF-α) and interferon-γ (IFN-γ)) by enzyme-linked immunosorbent assay (ELISA). Results showed that serum IgE levels in the guinea pigs sensitized by untreated shrimp protein and stimulated by shrimp protein with reduced allergenicity and the proteins extracted from shrimp meat and shelled shrimp with reduced allergenicity were (3.905 ± 0.120), (4.813 ± 0.188) and (5.199 ± 0.327) U/mL and HIS levels were (16.437 ± 1.120), (19.656 ± 1.080) and (21.071 ± 1.732) μg/mL, respectively. There was a positive correlation between the changes in serum IgE and HIS and allergenicity in the challenged animals. The changes in the serum levels of IL-1, IL-2, IL-3, IL-4, IL-6 and TNF-α were positively correlated with the allergenicity of shrimp products. These changes in cytokines were consistent with the changes in IgE and HIS contents. On the other hand, the change in IL-10 was negatively correlated with the allergenicity of shrimp products. Therefore, these seven cytokines had a good correlation with food allergy. Serum IFN-γ level did not show any correlation with the allergenicity of shrimp products, while the ratio of IFN-γ to IL-4 was decreased with the increase of allergenicity. Therefore, it is speculated that the Th1/Th2 cell balance in guinea pigs with food allergy is shifted towards Th2 cells.

Key words: Pacific white shrimp, allergenicity, cytokine, T helper cell balance