IgG4-positive Plasma Cell Infiltration in the Setting of Ulcerative Colitis

Abstract

AIM: IgG4 has gained medical attention due to its role in IgG4-related sclerosing disease. Among these, autoimmune pancreatitis (AIP) and sclerosing cholangitis have been well documented. Several reports describe an association between IBD and chronic pancreatitis. Primary sclerosing cholangitis (PSC) also has an established association with IBD, particularly ulcerative colitis (UC). Because of the aforementioned association between UC and sclerosing diseases,  further studies are in need to establish the presence and significance of IgG4 plasma cells in UC.

METHOD: Herein, we evaluate the significance of IgG4-positive plasma cells in 54 colonic biopsies of UC patients. The medical records were reviewed for demographic and clinical data including: the course of UC, the presence of any biliary symptoms or diagnosis of PSC, liver enzymes, IgG4-related disease and IgG4 serum levels. IgG4 positive plasma cells were recorded and categorized as follows: no=0, rare=1-2, few=3-9, many=10 or more.

RESULTS: Four cases had many IgG4 positive plasma cells, two of which had refractory UC course. Seven UC patients had elevated liver enzymes. Two of the 54 patients had primary sclerosing cholangitis. These patients had IgG4 labeling of none and rare.

CONCLUSION: In colonic biopsies of UC patients, and a subset with PSC, significant IgG4 plasma cell populations were not detected by immunohistochemistry. In a subset of UC patients with many IgG4 positive plasma cells a more severe clinical course was noted. Further studies are required to explore the significance of IgG4 in UC.