Disease Info

IgG4-related diseases (IgG4-RD) are a group of chronic relapsing remitting inflammatory conditions characterized by tissue infiltration with lymphocytes and IgG4-secreting plasma cells and subsequent tissue fibrosis. Frequently, tissue-destructive lesions may develop resulting from deposition of connective tissue in affected sites, even with organ failure.

IgG4-RD is often an indolent condition. People are generally well at the time of the diagnosis. Pain is generally a consequence of the obstruction or compression due to the presence of mass lesions and their complications. Multiorgan involvement can be present at the same time (synchronously) or different sites can be affected at different periods (metachronously).

Whatever organ or tissue are involved, a lymphoplasmacytic infiltrate rich in IgG4-positive plasma-cells, storiform fibrosis and obliterative phlebitis are the hystopathological hallmarks. The clinical suspicion may arise in the presence of elevated plasma IgG4 levels but the diagnosis often relies on histologic confirmation, as IgG4 levels may be normal.

To prevent fibrosis progression and organ destruction an induction and maintenance of remission is necessary. The first-line recommended agent are steroids. However, with taperig of steroids relapses are frequent, so steroid-sparing immunosuppressive agents can be considered. Finally, surgery or radiotherapy may be helpful in case of organ damage.