IGHE and viral infectious disease: Altogether, these data suggest that time-dependent eosinophilia is associated with immunological events and, more precisely, that transplant rejection could reflect (1) a humoral IgE response against the graft (DSA-IgE) and consecutive mast cell activation and (2) active viral infection (EBV, CMV) that activates/amplifies type 2 immunity against kidney transplantation.