Gastrointestinal: A case of IgG4‐related disease involving intestinal tract and orbital cavity

A 52-year-old woman was found to have prominent eyes for 2 years and was considered to have IgG4-related orbital disease with serum IgG concentration >31.6 g/L. After taking hormones and immunosuppressive agents for 3 days, she was found dark red stool with blood clot more than 10 times per day as well as other gastrointestinal symptoms. Abdominal computed tomography (CT) revealed the presence of wall thickening of small and large intestine, multiple nodular foci within the pancreas, and sub-lamella enhancement and reduction of the right liver (Fig. S1). Orbital CT revealed change of bilateral orbital soft tissue, while magnetic resonance cholangiopancreatography (MRCP) did not suggest imaging findings of IgG4-related diseases in hepatobiliary system and pancreas (Fig. S2). Colonoscopy found extensive congestive edema, erosion, and partial ulcer in ileum, colon, and rectum (Fig. 1). Histopathologic examination revealed neutrophils and plasma cell infiltration in sigmoid, and immunohistochemical results reported the ratio of IgG4: IgG was over 40% (Fig. S3). Gastrointestinal bleeding might be caused by IgG4-related disease involving intestinal tracts. The woman was then treated with hemostasis, hormones, and immunosuppressive agents, including methylprednisolone, hydroxychloroquine, and methotrexate according to rheumatology consultation. She barely had abdominal pain and bloody stools after taking the drugs regularly. Colonoscopy found hyperemia and edema were significantly relieved (Fig. 2). Pathology revealed infiltration of plasma cells and eosinophils, small erosion of mucous membrane, and dilatation and deformation of crypt gland in the colon (Fig. S4). The incidence of IgG4-related gastrointestinal diseases is low, and specific clinical manifestations are hardly identified. When swelling of multiple organs appeared, tumor or other autoimmune disease should be carefully distinguished. Elevated IgG4 in serum and IgG4-secreting plasma cells in tissues were keys to diagnose IgG4-related disease. Our case might help to improve the understanding of gastrointestinal and extraintestinal manifestation and pathology of IgG4-related disease. Figure S1: Chest and abdomen CT showing extensive intestinal wall thickening. Figure S2: The orbital CT revealing soft tissue change of bilateral orbital. Figure S3: Pathology showed infiltration of neutrophils and plasma cell in the sigmoid and immunohistochemical examination reported the ratio of IgG4: IgG was more than 40%. Figure S4: Pathology after treatment revealed infiltration of plasma cells and eosinophils, small erosion of mucous membrane, and dilatation and deformation of crypt gland in the colon. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.