IGHE and Alzheimer disease: Because serum IgE levels are correlated with the severity of AD and the serum levels of IgE, IgG1 and IgG2a are associated with Th2 or Th1 immunity [1, 31], we examined the serum levels of these three Igs in mice to evaluate the effects of DNCB and RPE on systemic Th1 and Th2 immunities (Table 1).