P3105 - Leflunomide Induced Lymphocytic Gastritis

Ravi B. Pavurala, MD¹, Andrew Heflin, BS², Qiu Suimin, MD, PhD³, Steven M. Cohn, MD, PhD^3
1University of Texas Medical Branch at Galveston, League City, TX; ²UTMB, Galveston, TX; ³University of Texas Medical Branch at Galveston, Galveston, TX

Introduction: Lymphocytic gastritis (LG) is a rare form of chronic gastritis characterized by numerous mature lymphocytes in the foveolar epithelium and lamina propria. Though exact etiology is not known, it is associated with helicobacter pylori infection and celiac disease. Medication-induced LG is rare and association with pembrolizumab has been reported. We describe a case of Leflunomide induced LG presenting as melena from upper gastrointestinal bleeding from superficial antral ulcers.

Case Description/Methods: A 61-year-old female with a history of osteoarthritis, hyperlipidemia, glaucoma, eczema, actinic keratoses, hypertension, rheumatoid arthritis (RA) treated with Leflunomide for the previous 3 years presents with melena and acute blood loss anemia. No history of non-steroidal anti-inflammatory drug use. Esophagogastroduodenoscopy (EGD) during the same admission showed three forest class III ulcers which were treated with pantoprazole 40 mg BID for three months. Stool Helicobacter pylori antigen was negative. Repeat EGD showed persistent 3 superficial antral ulcers with no stigmata of bleeding. Pathology of ulcers showed atypical cells with gastric mucosal ulceration and chronic active gastritis without Helicobacter pylori or intestinal metaplasia. The patient was restarted on pantoprazole, EGD a month later showed 5 superficial forest class III ulcers in gastric antrum. Pathology showed prominent regenerative and reactive changes in gastric mucosa and lymphoma was ruled out. Touch preparation and DQ slides showed small clusters of lymphoid cells. Immunophenotyping by flow cytometry of gastric biopsy showed limited cells positive for CD5 marker, but no abnormal B-cell or T-cell populations. Leflunomide was discontinued and EGD 4 months later showed resolution of gastric ulcers. Pathology of antral biopsies showed eosinophils in lamina propria, intraepithelial lymphocyte density suggestive of lymphocytic gastritis with the persistence of reactive and regenerative gastric mucosal changes.

Discussion: Leflunomide, used in rheumatoid arthritis, is a pyrimidine synthesis inhibitor and has anti proliferative and anti-inflammatory effect. Teriflunomide, the active metabolite has a median half-life of 18-19 days. Leflunomide associated lymphocytic colitis has been reported. We describe an adverse reaction of leflunomide, LG presenting as episodic bleeding gastric ulcers which resolved after discontinuation of the medication, which was hitherto not described.



Disclosures:


Ravi B. Pavurala, MD¹, Andrew Heflin, BS², Qiu Suimin, MD, PhD³, Steven M. Cohn, MD, PhD³. P3105 - Leflunomide Induced Lymphocytic Gastritis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.