IGHG3 and thyroid gland disorder: In terms of laboratory findings, compared with those without thyroiditis, patients with IgG4-related thyroiditis had higher levels of platelets (PLTs) (P = 0.013), lower levels of serum IgG4 and IgG3, and lower levels of T-IgE (P = 0.004, P = 0.050 and P = 0.006, respectively) (Table 3).