P1597 - A 21-year Appraisal of Autoimmune Gastritis and Its Complications At a Large Safety Net Hospital

Jasmine Lee, BA¹, Grace Kim, MD², Ramya Radhakrishnan, MD², Isa M. Jacoba, MD², Qing Zhao, MD, PhD², Haesook T. Kim, PhD³, Horst C. Weber, MD^1
1Boston Medical Center, Boston University School of Medicine, Boston, MA; ²Boston Medical Center, Boston, MA; ³Dana-Farber Cancer Institute, Boston, MA

Introduction: Autoimmune gastritis (AIG) is characterized by immune-mediated loss of parietal cells associated with reduced gastric acid output, vitamin B12 deficiency, and intestinal metaplasia. Enterochromaffine (ECL) cell hyperplasia (ECL-CH) represents the pathological hallmark. AIG might progress to gastric neuroendocrine tumor (gNET) type I and gastric adenocarcinoma.

Methods: A search for patients with biopsy-proven gastric lesions with neuroendocrine features was conducted from 2001 to 2022. Pathology samples were reviewed, categorized according to diagnoses of AIG with ECL-CH, gastric neuroendocrine tumor (gNET), and gastric adenocarcinoma with neuroendocrine (NE) features (GANE). The presence of intestinal metaplasia (IM) and dysplasia (ID) was recorded. Basic demographics and clinical characteristics were collected by chart review. Overall survival (OS) was estimated by the Kaplan-Meier method and log-rank test was used for group comparison.

Results: A total of 163 patients were identified with AIG by ECL-CH (N=130), gNET (N=20), and GANE (N=13). Baseline characteristics are summarized (Table). There was a significantly higher proportion (72.3%) of female AIG patients as compared to gNET and GANE (p=0.0028). The majority of AIG patients were Black (45%) and White (28%). Most AIG patients did not use PPI (73%), Aspirin (73%), and NSAIDs (76%). Of AIG patients, 23% had a history of H. pylori. B12 and iron deficiency were present in AIG patients (55%, 62%, respectively). Comorbid autoimmune disorders were noted in 29% (N=37) with thyroiditis being most common. Almost all AIG patients had IM (82%) but rarely ID, whereas in GANE ID was more prevalent (31%). OS was significantly longer in AIG (ECL-CH) and gNET (3-year OS 96% and 94% vs. 40%; p< 0.0001; figure, panel A). Survival between Black and White patients within the AIG (ECL-CH) was not significant (p=0.2), but OS overall was significantly longer for Black patients (Figure, panel B; p=0.04).

Discussion: This single-center retrospective study captured data of a unique, real-world cohort of patients with AIG, gNET, and GANE over a 21-year span. AIG patients were predominantly Black, had typical hematological complications, and IM was highly prevalent in this group in contrast to ID. Autoimmune disorders were noted prevalent in both AIG and gNET patients. A transition to gNET from ECL-CH was not directly captured in this 21-year review. Further studies are warranted to determine whether AIG maybe a precursor lesion for GANE.



Disclosures:


Jasmine Lee, BA¹, Grace Kim, MD², Ramya Radhakrishnan, MD², Isa M. Jacoba, MD², Qing Zhao, MD, PhD², Haesook T. Kim, PhD³, Horst C. Weber, MD¹. P1597 - A 21-year Appraisal of Autoimmune Gastritis and Its Complications At a Large Safety Net Hospital, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.