Immunoglobulin G4-Related Disease
A spectrum of systemic autoimmune diseases in which IMMUNOGLOBULIN G4 plays a pathophysiologic role. It can affect multiple organs in highly variable presentations, characterized by inflammatory lesions composed of IgG4-positive PLASMA CELLS, further infiltrated by T helper cells (T-LYMPHOCYTES, HELPER-INDUCER) when linked to progressive FIBROSIS and eventual organ damage.