IL5 and Increased total eosinophil count: EF response to tocilizumab may be because eosinophilia and hypergammaglobulinemia in EF are explained by high production of IL-5 and IL-6 by mononuclear.39 In addition, eosinophils, which play a key role in EF, degranulate and release cytokines like IL-6 as explained before in “pathophysiology”.5