IGHE and Autoimmunity: This is in agreement with the study of Smith et al. [29], which found a higher prevalence of both conditions in patientswith serum IgE levels below 2.5 kU/l, suggesting the existence of commongenetic factors that may predispose to both IgE deficiency and autoimmunity.Other authors have proposed that deregulation of molecules and signals thatplay a key role in B-cell activation and terminal differentiation could beinvolved in initiating or maintaining autoimmunity [35].