IL5 and Increased total eosinophil count: The mechanism can be considered both clonal and reactive, since eosinophilia is reactive to the eosinophilopoietic growth factors (mainly IL-5, but also IL-4 and IL-13) produced by the abnormal population of T-lymphocytes, with atypical pattern of surface markers and a T helper cell type 2 (Th2) cytokine profile [20].