P2695 - A Case of Rare IgG4-Related Disease

Katie Clark, ¹, Adarsh Varma, MD², Syed-Mohammed Jafri, MD^3
1Wayne State University School of Medicine, Detroit, MI; ²Henry Ford Health, Detroit, MI; ³Henry Ford Health System, Detroit, MI

Introduction: Immunoglobulin G4 Related Diseases (IgG4RD) are systemic disorders characterized by organ enlargement and fibrosis. IgG4RDs can manifest in multiple organ systems and are often accompanied by elevated serum IgG4 levels. We present a unique case of a rarer IgG4RD, Sclerosing Mesenteritis, which primarily affects the mesentery of the small intestines.

Case Description/Methods: An 85 year old female presents with unexplained weight loss, abdominal pain, and loose stools. Initial CT revealed increased density of adipose tissue in the small bowel mesentery as well as upper abdominal and mesenteric adenopathy. Fine needle aspiration eliminated concern for lymphoma and angiography revealed Superior Mesenteric and Celiac Artery stenosis. A stent was placed but it failed to relieve symptoms. She was diagnosed with IgG4 related disease, based on presence of mesenteric adenitis, sicca symptoms, and following excisional biopsy of mesenteric lymph nodes which revealed elevated IgG4 levels. She briefly underwent a course of steroids, associated with a decrease in IgG4 levels from 655 mg/dL to 333 mg/dL but has failed to comply with continued treatment. Abdominal symptoms worsened in intensity and revaluation of IgG4 revealed a significant increase to 894 mg/dL but repeat CT showed stable disease progress. Upper GI colonoscopy showed gastritis, large hiatal hernia, and suspected Barrett's esophagus which was later confirmed by pathology, for which she was started on Prilosec. Biopsy findings also included duodenal lymphoid aggregates and metaplasia, hyperplastic polyps, mild chronic gastritis, and regenerative changes in stomach. Development of rectal bleeding is thought to be due to a diverticular bleed. Patient has been diagnosed with Sclerosing Mesenteritis and IgG4 related Interstitial Lung Disease and is awaiting further workup from rheumatology.

Discussion: The above case illustrates the complexity in diagnosing IgG4RD. The patient’s unexplained weight loss and GI symptoms combined with elevated IgG4 levels are hallmark characteristics of IgG4RD, although the apparent restriction to small intestine mesentery and lymph node involvement highlighted the likelihood of Sclerosing Mesenteritis specifically, as it is characterized by less direct organ involvement as compared to other IgG4RDs. Careful evaluation of pathology was required to rule out similarly presenting diseases such as lymphoma. This case was made more complex by the patient’s non compliance with medication regimens and consistent follow up.


Disclosures:


Katie Clark, ¹, Adarsh Varma, MD², Syed-Mohammed Jafri, MD³. P2695 - A Case of Rare IgG4-Related Disease, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.