A case of early autoimmune gastritis with characteristic endoscopic findings

Autoimmune Gastritis in Korean Patients with Gastric Tumors: Clinicopathologic Correlations and Diagnostic Histological Features

Background/Aims

Autoimmune gastritis (AIG) is a corpus-dominant atrophic gastritis in which patients are positive for antiparietal cell antibody (APCA) and/or anti-intrinsic factor antibody. The risk of developing gastric cancer in patients with AIG remains unclear, and reliable frequency data of AIG in patients with gastric cancer are lacking.

Methods

We included 624 Korean patients with gastric tumors (612 gastric cancers and 12 neuroendocrine tumors) who had APCA results and were available for AIG evaluation. In patients with positive APCA results, endoscopy and histology findings were reviewed to diagnose AIG.

Results

Of the 624 patients, 37 (5.9%) tested positive for APCA, and ultimately, 11 (1.8%) met the diagnostic criteria for AIG (5 both endoscopy and histology findings, 4 endoscopy-only findings, 2 histology-only findings). The frequency of AIG in patients with gastric cancer was 1.3% (8/612), and that in patients with neuroendocrine tumors was 25.0% (3/12). Of the 11 patients with AIG, serum Helicobacter pylori antibody was positive in six patients (54.5%), all of whom had gastric cancer. Histologically, three patients showed pure AIG, four patients exhibited concurrent AIG and H. pylori gastritis, and the findings for four were indefinite for AIG. The pepsinogen (PG) I levels and PG I/II ratio were significantly lower in patients with gastric cancer with AIG than in patients with gastric cancer without AIG (p=0.042 and p=0.016, respectively).

Conclusions

The frequency of AIG in gastric cancer patients was very low compared to that in patients with neuroendocrine tumors. Rather, concurrent AIG and H. pylori gastritis was common in patients with AIG with gastric cancer.

Rapid Development of a Hemorrhagic Hyperplastic Polyp in a Patient with Evolving Autoimmune Gastritis after Helicobacter pylori Eradication

In 2020, a 56-year-old woman with a history of Helicobacter pylori (H. pylori) eradication 9 years previously presented with a hemorrhagic hyperplastic polyp. Endoscopic and histological findings led to the diagnosis of advanced-stage autoimmune gastritis (AIG). A review of endoscopic findings from 2014 was available, and narrow-band imaging showed swelling of the gastric areas, characteristic of early-stage AIG. Together with the rapid growth of a hyperplastic polyp, these findings suggest a case of AIG that rapidly exacerbated after eradication. To our knowledge, this is the first case report of a rapidly developing hemorrhagic hyperplastic polyp associated with AIG after H. pylori eradication.

Unveiling early stage autoimmune gastritis: novel endoscopic insights from two case reports

The predominant characteristic of autoimmune gastritis (AIG) is corpus-dominant advanced atrophy, which is mostly observed in the middle to late stages. More reports are needed on the endoscopic features of the early stage. In this report, we present two cases of early-stage AIG in which endoscopic examinations showed no atrophy of the gastric mucosa but displayed a transition of collecting venules from a regular to an irregular arrangement. In addition, yellowish-white cobblestone-like elevations were observed in the fundic gland region. Histologically, the observed manifestations included pseudohypertrophy and protrusion of parietal cells into the lumen, possibly along with hyperplasia of G cells, lymphocytic infiltration and potentially pseudopyloric gland metaplasia. Serologically, the anti-parietal cell antibody returned positive results, whereas the anti-intrinsic factor antibody yielded negative results. In this study, we summarized some endoscopic features of two patients, aiming to provide clues for endoscopists to detect early-stage AIG.

Characteristic endoscopic findings in early-stage autoimmune gastritis

Background and study aims Until recently, autoimmune gastritis (AIG) was usually diagnosed at late stages based on typical endoscopic findings, including corpus-dominant advanced atrophy. Early-stage AIG prior to complete gastric atrophy had rarely been diagnosed due to a lack of knowledge about its endoscopic characteristics. The present study sought to identify the endoscopic characteristics of early-stage AIG, enabling its early diagnosis. Patients and methods The clinical and endoscopic findings of 12 patients diagnosed with early-stage AIG between 2016 and 2021 were retrospectively evaluated. Patients were included if they were: (1) positive for serum anti-parietal cell antibody; (2) diagnosed with histological early-stage AIG; and (3) endoscopically positive for folds on the greater curvature of the gastric corpus. Results Two characteristic endoscopic findings of early-stage AIG were identified: longitudinal alignment of pseudopolyps (i.e., a bamboo joint-like appearance) and swelling of gastric areas with erythema (i.e., a salmon roe-like appearance). Conclusions Endoscopic findings characteristic of early-stage AIG include a bamboo joint-like appearance and a salmon roe-like appearance. Studies in large numbers of patients with long-term follow-up are needed to confirm these findings.

Autoimmune Gastritis: Focus on Endoscopic and Morphological Characteristics

Aim: tosystematize the literature data on endoscopic semiotics and morphological changes in the gastric mucosa in autoimmune gastritis.

Key points. Autoimmune gastritis is associated with an increased risk of developing adenocarcinoma and neuroendocrine tumours of the stomach. Clarification of diagnostic criteria for autoimmune gastritis is essential for gastroenterological practice. The diagnosis is based on the results of endoscopic and histological examination, and on data from laboratory tests. Isolated atrophy of the mucous membrane of the body of the stomach, the presence of difficult-to-wash creamy mucus, changes in the mucous membrane like “shed skin”, and the presence of whitish globule-like foci are typical endoscopic signs of autoimmune gastritis. Widespread pseudopyloric metaplasia, focal intestinal and pseudopancreatic metaplasia, hyperplasia of the ridges of the mucous membrane of the body of the stomach and their relationship to the glandular layer as in the antrum allow during a morphological study considering clinical data to suspect and verify autoimmune gastritis.

Conclusion. During instrumental examination, knowledge of endoscopic symptoms and pathognomonic morphological changes is important for the timely diagnosis of autoimmune gastritis.

Histopathologic diagnosis of ultra-early autoimmune gastritis: A case report

We describe an ultra-early stage of autoimmune gastritis (AIG) that occurs prior to the well-known early-stage AIG. The key pathology is the shortening of the second layer with degenerated parietal cells. In the management of patients with autoimmune diseases, AIG should be considered even if the endoscopy findings are normal.

Diagnostic criteria and endoscopic and histological findings of autoimmune gastritis in Japan

The Japanese diagnostic criteria for autoimmune gastritis (AIG) were established by the "Study Group on the establishment of diagnostic criteria for type A gastritis," which is related to a workshop associated with the Japan Gastroenterological Endoscopy Society (JGES) and the Committee of AIG Research Group (CARP). The criteria were set as follows: the cases of confirmed diagnosis are patients in whom either the endoscopic or histological findings, or both, meet the requirements for AIG and who are confirmed to be positive for gastric autoantibodies (either anti-parietal cell or anti-intrinsic factor antibodies, or both). The presentation of endoscopic findings of early-stage AIG in the diagnostic criteria was withheld owing to the need for further accumulation and characterization of endoscopic clinical data. Therefore, diagnosis of early-stage AIG only requires histological confirmation and gastric autoantibody positivity. Suspected cases are patients in whom either the endoscopic or histological findings, or both, meet only the requirements for AIG. Histological findings only meet the requirements for early stage. AIG has been underdiagnosed in the past, but our study group's newly proposed diagnostic criteria will enable a more accurate and early diagnosis of AIG. The criteria can be used to stratify patients into various high-risk groups for gastric tumors and pernicious anemia. They would allow the establishment of an appropriate surveillance system in the coming years. Nevertheless, issues such as establishing the endoscopic findings of early-stage AIG and obtaining Japanese insurance coverage for gastric autoantibody tests require attention.

Parietal Cell Dysfunction: A Rare Cause of Gastric Neuroendocrine Neoplasm with Achlorhydria and Extreme Hypergastrinemia

A 69-year-old woman with multiple neuroendocrine neoplasms (NENs) was referred to our hospital. Although she had extreme hypergastrinemia (11,675 pg/mL), no findings that indicated types I to III gastric NENs were found. Although gastric corpus atrophy was suspected on conventional white-light imaging, findings on magnifying endoscopy with narrow-band imaging indicated no severe atrophy. A biopsy from the background fundic gland mucosa revealed no atrophic changes, parietal cells with vacuolated cytoplasm and negative findings for H+K+-ATPase. Thus, this case was diagnosed as multiple NENs with parietal cell dysfunction. Neither progression nor metastasis has been confirmed during two-year follow-up.

Endoscopic Features of Autoimmune Gastritis: Focus on Typical Images and Early Images

Autoimmune gastritis (AIG) is chronic atrophic gastritis caused by an autoimmune mechanism of unknown etiology and presents with various pathological conditions by causing an achlorhydria state through parietal cell damage. The most characteristic endoscopic finding in AIG is advanced corpus-dominant mucosal atrophy. A recent study that examined several cases in Japan revealed the presence of endoscopic features other than corpus-dominant advanced atrophy. Remnants of oxyntic mucosa and sticky adherent dense mucus were found in ≥30% of cases, and hyperplastic polyps were found in ≥20% of cases. In image-enhanced endoscopy (IEE), white globe appearance (WGA) was observed in 32% of AIG cases. Additionally, some reports have stated that the findings in AIG cases using IEE showed cast-off skin appearance (CSA) and foveola type mucosa; however, a consensus is yet to be achieved. These endoscopic results were found in cases of advanced-stage AIG. There have been few reports concerning early-stage AIG cases. In these few reports, all of the cases were pathologically diagnosed as early AIG. In all of the cases, the pathological findings almost always showed neither parietal cell destruction nor atrophy. Endoscopic findings such as “mosaic pattern with slight swelling of the areae gastricae”, “diffuse reddened and edematous gastric fundic gland mucosa”, and “pseudopolyp-like nodules” may be common characteristics of early images. In such early cases, high antibody titers, no atrophic changes, and few clinical abnormal findings were shown. Endoscopists are expected to update their knowledge regarding AIG diagnosis with the evolution of imaging equipment.

Early autoimmune gastritis presenting with a normal endoscopic appearance

This report describes a patient with early-stage autoimmune gastritis (AIG) presenting with a normal endoscopic appearance. A 66-year-old man with autoimmune thyroiditis was suspected of having AIG because of a previous history of vitamin B12 deficiency when receiving steroid therapy for interstitial pneumonia 5 years earlier. At presentation, he tested positive for anti-parietal cell antibody (1:320) and anti-intrinsic factor antibody, but not for vitamin B12 deficiency. His gastrin level was elevated (338 pg/mL), but his pepsinogen (PG) I level (56.1 ng/mL) and PGI/PGII ratio (7.6) were normal. Endoscopically, neither atrophic nor inflammatory changes were observed. Histopathologic examination, however, showed mild atrophic changes with dense lymphocytic infiltration in the deep lamina propria and focal destruction of parietal cells in the greater curvature of the corpus. PGI-positive/MUC6-positive pseudo-pyloric metaplasia was observed in the area from which H+/K+-ATPase-positive parietal cells had disappeared. Chromogranin A immunostaining showed linear hyperplasia of enterochromaffin-like cells. By contrast, atrophic changes were not evident in the lesser curvature of the corpus, except for mild lymphocytic infiltration around and into the fundic glands. These serological and histopathological findings suggested that the patient had early-stage AIG with a normal endoscopic appearance.

Endoscopic features and clinical importance of autoimmune gastritis

Autoimmune gastritis (AIG) is a special type of chronic gastritis characterized by autoimmune disorders caused by cellular immunity, resulting in the destruction of parietal cells and production of antiparietal cell antibodies. Endoscopic findings of AIG are mainly characterized by corpus-dominant advanced atrophy. The antral area is generally considered to have no or mild atrophy; however, there are cases wherein the gastric mucosa is red or faded due to past infection with Helicobacter pylori or bile reflux. Currently, there are no diagnostic criteria for AIG in Japan, and it is important to make a diagnosis based on the presence of gastric autoantibodies and characteristic endoscopic and histological findings. AIG is associated with gastric cancer, neuroendocrine tumors (NETs), and other autoimmune diseases, such as thyroid diseases, anemia, and neurological symptoms due to impaired absorption of iron and vitamin B12 , and thus requires systemic treatment. The significance of diagnosing AIG is to include patients as a high-risk group for the development of gastric cancer and gastric NETs, provide an opportunity to detect autoimmune endocrine diseases, and initiate therapeutic intervention before anemia and neurological symptoms develop. It is important to pay close attention to the occurrence of AIG comorbidities not only at the time of AIG diagnosis but also during follow-up after detection.

An Evaluation of Endoscopic Images from Over 15 Years Prior to the Diagnosis of Autoimmune Gastritis: A Report of Three Patients

We herein describe three patients whose endoscopic images from over 15 years prior to their diagnosis of autoimmune gastritis (AIG) were available for review. All patients had corpus-dominant atrophic gastritis at the time of the diagnosis of AIG. Previous endoscopic images without severe atrophy showed erythema restricted to the fundic mucosa. These findings are suggestive of ongoing gastritis in patients with AIG. Initial endoscopy in Patient 2 showed multiple hyperplastic polyps that decreased in size and number over the course of 15 years. In this patient, circular wrinkle-like patterns and remnant oxyntic mucosa were visible after the atrophy had become quite prominent.

Evolving Autoimmune Gastritis Initially Hidden by Active Helicobacter pylori Gastritis

Autoimmune gastritis (AIG) and Helicobacter pylori (H. pylori) gastritis are considered different diseases but exhibit overlapping features. We herein report a case of evolving AIG that had been initially hidden by active H. pylori gastritis. The patient was diagnosed with active H. pylori gastritis and received first-line eradication therapy in 2014 and successful second-line therapy in 2017. She was suspected of having early-stage AIG in 2019 based on the endoscopic finding of salmon roe-like nodular lesions on the greater curvature of the corpus. Parietal cell antibody was positive and the serum gastrin level was slightly elevated. Although subsequent endoscopy in 2020 revealed no significant changes in gastric atrophy, a sharp rise in the serum gastrin level was noted. A biopsy specimen taken from a nodular lesion showed pseudohypertrophy of residual parietal cells, lymphocytic infiltration, and enterochromaffin-like (ECL) cell hyperplasia. Upon retrospective reviews, endoscopic and serological findings obtained before eradication were consistent with active H. pylori gastritis. However, endoscopic salmon roe-like nodular lesions were detected in close-up views. In addition, lymphocytic destruction of fundic glands, pseudopyloric metaplasia, and ECL cell hyperplasia was histopathologically identified on a background of full-thickness inflammation, which suggested that early-stage AIG had coexisted with active H. pylori gastritis.