Abstract

IgG4-related disease (IgG4-RD) is a chronic immune-mediated condition that can affect almost any organ. The disease is characterized by IgG4+ plasma cell- rich infiltrates, fibrosis, obliterative phlebitis; in most cases IgG4 serum concentrations are also elevated. IgG4-RD primarily affects middle-aged and older males. This disease often takes many years to diagnose, because of its mimicking characteristics. To facilitate recognition of IgG4-RD, clinical phenotypes can be used. These phenotypes are pancreato-biliary involvement, retroperitoneal fibrosis with or without aortitis, head and neck limited form and Mikulicz’s syndrome with systemic involvement. These phenotypes also represent the most common sites of IgG4-RD. All aspects of this disease are not yet known, nevertheless, IgG4-RD can be diagnosed based on clinical characteristics, histology, serology, radiological evaluation, and glucocorticoids` responsiveness. Early diagnosis, appropriate treatment and avoiding relapses
are crucial to avoid organ damage and to improve prognosis.