Stage classification of IgG4-related dacryoadenitis and sialadenitis by the serum cytokine environment

These results suggest that there are clinical stages in IgG4-RD, and serum IL-5 play roles in the pathogenesis of IgG4-RD.

Definite IgG4-related dacryoadenitis and sialadenitis (IgG4-DS) cases were divided according to the CDC for IgG4-RD into 11 cases with focal type and 30 cases with systemic type. The levels of serum interleukin (IL)-4, IL-5, IL-6, IL-10, IL-13, IL-15, IL-21, interferon (IFN)-α, IFN-γ, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, and monocyte chemotactic protein (MCP)-1 were measured in healthy controls, allergic patients, probable IgG4-RD cases, and focal and systemic type cases. The cytokine environment was analyzed in each group. The 52 definite IgG4-RD cases were next classified into four groups with cluster analysis in terms of therapeutic responses and prognosis. The relationships between each cytokine level and therapeutic responses were also analyzed.

Both serum IL-5 and IFN-α concentrations were very low in healthy controls, but they increased in the allergic cases, probable cases, and focal and systemic type cases. The level of serum IL-5 was significantly higher in definite cases than in healthy controls. The serum IL-5 level was also significantly increased in the groups with a poor prognosis than in the good prognosis group.