SSB and systemic lupus erythematosus: It has been reported that much similar pathogenesis have existed between patients with pSS and SLE [2, 22, 26], including the type I and type II IFN system in the innate immune phase, and autoantibodies such as anti-SSA/SSB and antinuclear antibody consistently appeared in both diseases, but not for IgG4-RD.