The Th1/Th2 paradigm in AD has been revised, with evidence of a significant role for the IL-17 and IL-22-secreting Th17 and IL-22-secreting Th22 cell subtypes.24, 25, 26, 27 Thus, during the acute phase of AD, in addition to Th2 cytokines such as IL-4, IL-13 and IL-31, there is a predominance of IL-22, as well as smaller amounts of Th17 cells.28 Here, IL17A is linked to Alzheimer disease.