IL4 and asthma: An analysis comparing 11 studies shows that treatment with dupilumab resulted in a transient increase in mean blood eosinophil counts in patients with asthma or AD, which usually decreased to baseline or below over time and was generally not associated with clinical symptoms or an effect on efficacy (44) As IL-4 and IL-13 do not mediate eosinophil maturation and release into the blood, this reduction in eosinophil migration into the tissue may lead to a transient increase in blood eosinophil counts (44).