The western environment has increased hay fever symptoms and IL-10 levels in Chinese immigrants

Aim: To identify whether migration to a new environment alters the prevalence of allergy and immune responses in Chinese immigrants. Method: Chinese immigrants recruited for this study (N = 142) were required to fill in a questionnaire pertaining to allergic symptoms and residency status in Australia. A skin prick test was performed on each subject to determine atopy. Peripheral blood mononuclear cells were extracted from blood samples and cultured with house dust mite (HDM) and phytohaemagglutinin. Cytokine levels of IL-5, IL-10, IL-13 and IFN-γ were analyzed using Dissociation-enhanced lanthanide fluorescent immunoassay. Results: We found that levels of IL-10 (p = 0.031) and the incidence of hay fever (p = 0.013) increased with duration of residence in Australia. In addition, immigrants residing in Australia for 1.8 – 2.5 years were more likely to be sensitized to two species of HDM, Dermatophagoides farinae (p = 0.026) and Dermatophagoides pteronyssinus (p = 0.001), while those residing in Australia for an average of 7.5 – 7.9 years were more likely to develop sensitization to mixed rye grass (p = 0.031) and mixed grass (p = 0.021). These results were independent of age and gender. Conclusion: An increase in hay fever symptoms and levels of IL-10 was present in Chinese immigrants who have lived in Australia for a longer period of time.