IgG4-Related Disease

IgG4-related disease (IgG4-RD) is one of the newest autoimmune diseases. The disease causes pseudo-tumoral lesions damaging tissues in multiple organs. Its prevalence and incidence are low, and many conditions can mimic IgG4-RD. Since there is no specific test or feature to make a strong diagnosis, two sets of diagnostic criteria have been developed: The Comprehensive Diagnostic Criteria and the International Consensus on Pathology Criteria. They are based on typical organ involvement, bloodwork, and pathology. Relapses are frequent, and organ involvement can lead to permanent damage. Treatment of IgG4-RD is based on glucocorticoids and steroid-sparing agents.