Autoimmune gastritis is a chronic condition mediated by autoantibodies that destroy gastric parietal cells, resulting in hypochlorhydria and intrinsic factor deficiency—an essential protein for vitamin B12 absorption in the terminal ileum. The lack of this vitamin impairs DNA synthesis, primarily affecting tissues with high cellular turnover, such as bone marrow, leading to the production of macrocytic and morphologically altered red blood cells, characteristic of megaloblastic anemia. When caused by autoimmune destruction of intrinsic factor, this condition is referred to as pernicious anemia.

To identify immunological and inflammatory biomarkers with potential to improve the early diagnosis of autoimmune gastritis associated with megaloblastic anemia.

A narrative literature review was conducted using the PubMed/MEDLINE database to identify recent evidence on diagnostic biomarkers in autoimmune gastritis associated with megaloblastic anemia. The search terms “megaloblastic anemia” AND “gastritis” were used. The search was carried out in June 2025 and limited to articles published between 2019 and 2024. Included studies were original or review articles focusing on humans, published in English, and with free full-text access. Exclusion criteria comprised studies focusing exclusively on pediatric populations, animal models, duplicates, and those not directly addressing the association between the conditions studied.

Early detection of autoimmune gastritis remains challenging due to the nonspecific nature of initial symptoms and overlap with other nutritional anemias. Incorporating gastric autoantibodies and inflammatory biomarkers such as IL-19 could enhance diagnostic sensitivity and enable earlier intervention. Identifying at-risk individuals, combined with specific laboratory testing, may prevent irreversible neurological outcomes and optimize clinical management.

Autoimmune gastritis associated with megaloblastic anemia continues to be underdiagnosed in its early stages. The use of immunological and inflammatory biomarkers appears promising for early diagnosis, reducing associated morbidity and improving clinical prognosis.