Immune disease markers (Antinuclear antibody, Rheumatic factor, Cryoglobulin, IgM, IgA, IgE, IgG and IgG4), viral markers (CMV IgM and IgG, EB-VCA IgM and IgG, EBEA and EBNA, HSV IgM) and inflammatory marker (C-reactive protein) were found to be negative in all patients of this study cohort, which suggests this study population has no individual with detectable immune complex deposition. Here, IGHE is linked to immune system disorder.