IGHG3 and dengue disease: Interestingly, patients who developed dengue fever (DF), the mild form of dengue disease, had higher levels of IgG3 (a Th1-associated antibody) and lower levels of IgG4 (a Th2-associated antibody) compared with those who developed dengue hemorrhagic fever (DHF), a severe form of dengue (Figure 9, A–C).