Alaaeldin M Bashier, Ghita Harifi, Elamin I Abdelgadir
IgG4-related disorders (IgG4-RD) are a new entity of multi-organ disorders that share common fibro-inflammatory histopathologic characteristics and elevated IgG4 levels in serum and tissue. Autoimmune pancreatitis and Mikulicz syndrome are major entities, however many syndromes are part of IgG4-RD including eosinophilic angiocentric fibrosis, fibrosing mediastinitis, hypertrophic pachymeningitis, inflammatory pseudotumour, multifocal fibrosclerosis (commonly affecting the orbits, thyroid gland, retroperitoneum, mediastinum, and other tissues and organs), periaortitis and peri-arteritis, inflammatory aortic aneurysm, retroperitoneal fibrosis (Ormond’s disease), Riedel’s thyroiditis, and sclerosing mesenteritis. In this review we detail the link between IgG4-RD and endocrine disorders and then examine the link between diabetes and IgG4-RD. We study the increased risk of IgG4-RD after using dulaglutide. We concluded that IgG4-RD should be suspected in patients with progressive thyroiditis with mass effect and very high antibody titers. The relationship between IgG4-RD and diabetes is still controversial.