IL17A and brucellosis: Simultaneously, the IL-22, as a cytokine related to defense of epithelial cells against invading pathogens was increased in acute and relapse patients providing some evidence for protective immunity against Brucella. Another recent study for a brucellosis cohort from China also showed increased levels of IL-17A in acute (defined as duration of disease was less than 6 months) and chronic infections (defined as not recovered for more than 6 month), but in contrast, Th17 cell counts was not significantly elevated (Zheng et al., 2019).