Search Results (20)

Autoimmune gastritis (AIG) is an uncommon and often underestimated condition in children, characterized by chronic stomach inflammation leading to the destruction of oxyntic glands with subsequent atrophic and metaplastic changes. This condition is associated with hypo-/achlorhydria, impairing iron and vitamin B12 absorption. The pathogenesis involves the activation of helper type 1 CD4+/CD25-T-cells against parietal cells. Clinical manifestations in children are not specific and include abdominal pain, bloating, nausea, vomiting, and iron deficiency anemia (IDA). The disease is also linked to an increased risk of pernicious anemia, intestinal-type gastric cancer, and type I neuroendocrine tumors. AIG is often diagnosed through the presence of autoantibodies in the serum, such as parietal cell (APCA) and intrinsic factor (IF) antibodies. However, therapeutic recommendations for pediatric AIG are currently lacking. We aim to present two clinical cases of pediatric-onset AIG, highlighting the heterogeneous clinical manifestations and the challenges in diagnosis with the support of an updated literature review. A 9-year-old girl presented with refractory IDA, initial hypogammaglobulinemia, and a 12-year-old boy was initially diagnosed with eosinophilic esophagitis. Both cases underline the importance of considering AIG in children with chronic gastrointestinal symptoms and gastric atrophy. Diagnostic workup, including endoscopy and serological tests, is crucial for accurate identification. A better understanding of this condition is imperative for timely intervention and regular monitoring, given the potential long-term complications, including the risk of malignancy. These cases contribute to expanding the clinical spectrum of pediatric AIG and highlight the necessity for comprehensive evaluation and management in affected children. Full article

Food cobalamin malabsorption (FCM) represents a prevalent, often underdiagnosed, etiology of vitamin B12 deficiency, particularly within an aging population. Unlike pernicious anemia, an autoimmune disorder targeting intrinsic factor, FCM stems from the impaired release of cobalamin from food proteins, primarily due to age-related gastric changes, medication-induced gastric hypochlorhydria, metformin, or non-immune atrophic gastritis. The clinical presentation of FCM mirrors that of general cobalamin deficiency, encompassing a spectrum of neurological (peripheral neuropathy, cognitive decline), hematological (megaloblastic anemia), and gastrointestinal (glossitis, anorexia) manifestations. Given the potential for irreversible neurological sequelae, early detection and intervention are paramount. High-dose oral cobalamin (125–250 mcg daily) has demonstrated efficacy, offering a convenient and cost-effective alternative to parenteral administration. Full article

Introduction: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are becoming more popular in managing type 2 diabetes mellitus (T2DM). Concerns linger over potential links to malignancies like pancreatic and thyroid cancers, requiring more research to clarify their safety profiles. Additionally, evidence suggests GLP-1 RAs may lower colorectal and pancreatic cancer risk, especially in obese and overweight individuals, indicating a protective effect beyond weight loss. Current studies leave a gap in comprehensively understanding cancer risks associated with GLP-1 RAs, which prompts further research to enhance our understanding of their overall safety. Methods: We queried the US Collaborative Network (63 health care organizations) of the TriNetX research database. Patients with T2DM were identified and divided into two cohorts: patients on GLP-1 RAs and patients not on GLP-1 RAs. We excluded tobacco use and alcohol use disorders, obese patients with a body mass index (BMI) of >25 kg/m², and those with a family history of gastrointestinal malignancy, infectious mononucleosis, chronic gastritis, pernicious anemia, helicobacter pylori infection, or gastroesophageal reflux disease (GERD). We used a 1:1 propensity score matching (PSM) model using patients’ baseline characteristics, medications, labs, and genetics. We compared the rate of gastric cancer and esophageal cancer at the seven-year mark. Results: A total of 2,748,431 patients with T2DM were identified. Of those, 6% (n = 167,077) were on a GLP-1 RA and 94% (n = 2,581,354) were not on a GLP-1 RA. After PSM, both cohorts included 146,277 patients. Patients with T2DM who were on a GLP-1 RA, compared to those who were not, had a statistically significant lower risk of both gastric cancer (0.05% vs. 0.13%, p < 0.0001) and esophageal cancer (0.04% vs. 0.13%, p < 0.0001) at the seven-year mark. Conclusion: The use of GLP-1 RAs in patients with T2DM does not significantly increase the risk of gastric or esophageal cancer. This finding supports the continued use of GLP-1 analogues as a therapeutic option in managing T2DM, considering their well-established benefits and low risk of complications. Based on the study results, these medications may even have a protective effect against these malignancies. Full article

Parietal cell autoantibodies (PCAs), which recognize the enzyme H+/K+-ATPase as a target, are considered to be a diagnostic marker of autoimmune gastritis and pernicious anemia; these conditions are characterized by the presence of corpus atrophic gastritis. Circulating PCAs can be detected using several analytical methods that are commonly available in the clinical laboratory. Traditionally, indirect immunofluorescence (IIF) on rodent or primate stomach tissue is used as a screening test for the detection of PCAs. However, IIF suffers from a high inter-observer variability and lacks standardization. In addition, like immunoblotting, results are expressed only in a qualitative or semi-quantitative manner. Based on the few available studies that are reviewed herein, quantitative enzyme-linked immunosorbent assays (ELISAs) and fluorescence enzyme immunoassays (FEIAs) using purified H+/K+-ATPase perform better than IIF in the detection of PCAs, displaying higher sensitivity and utility in monitoring the disease. In light of their higher diagnostic accuracy, these solid-phase methods should be preferred to IIF in the screening of autoimmune atrophic gastritis. The use of methods to detect antibodies versus a specific subunit of H+/K+-ATPase (α or β) is currently confined to the world of research. Further investigation is required to define the clinical utility of H+/K+-ATPase subunit detection. Full article

Autoimmune atrophic gastritis is an immune-mediated disease resulting in autoimmune destruction of the specialized acid-producing gastric parietal cells. As a consequence, in autoimmune atrophic gastritis, gastric acid secretion is irreversibly impaired, and the resulting hypochlorhydria leads to the main clinical manifestations and is linked, directly or indirectly, to the long-term neoplastic complications of this disease. In the last few years, autoimmune atrophic gastritis has gained growing interest leading to the acquisition of new knowledge on different aspects of this disorder. Although reliable serological biomarkers are available and gastrointestinal endoscopy techniques have substantially evolved, the diagnosis of autoimmune atrophic gastritis is still affected by a considerable delay and relies on histopathological assessment of gastric biopsies. One of the reasons for the diagnostic delay is that the clinical presentations of autoimmune atrophic gastritis giving rise to clinical suspicion are very different, ranging from hematological to neurological–psychiatric up to gastrointestinal and less commonly to gynecological–obstetric symptoms or signs. Therefore, patients with autoimmune atrophic gastritis often seek advice from physicians of other medical specialties than gastroenterologists, thus underlining the need for increased awareness of this disease in a broad medical and scientific community. Full article

Autoimmune gastritis (AIG) is characterized by the destruction of gastric parietal cells, resulting in hypochlorhydria and eventual achlorhydria, as oxyntic glands in the corpus are destroyed and become atrophic. The permanent loss of gastric acid has many impacts—both theoretical and documented. The most concerning of these are hypergastrinemia and increased N-nitroso compounds, both of which increase the risk of gastric cancers. While known deficiencies of B12 and iron are often replaced in AIG, acid is not. Moreover, patients with AIG are often prescribed acid suppression for a stomach that is decidedly no longer acidic, worsening the sequelae of gastric atrophy. Betaine hydrochloride (BHCL) is a short-acting acidifying agent, available over the counter in capsule form. Mealtime acid supplementation has an historic basis and could ameliorate many AIG-related gastrointestinal symptoms. Theoretically, acidification could also reduce the potential for hypergastrinemia and the production of N-nitroso compounds, consequently reducing the risk of gastric cancers. Supplemental vitamin C may also help in preventing gastric N-nitroso formation, regardless of the gastric pH. This narrative review describes the functions of gastric acid in gastrointestinal and immune health, documents the effects of hypochlorhydria in AIG, and proposes potential options for safely re-establishing the acid milieu of the stomach for patients with AIG. Full article

Circadian rhythm disorders pose major risks to human health and animal production activity, and the hypothalamus is the center of circadian rhythm regulation. However, the epigenetic regulation of circadian rhythm based on farm animal models has been poorly investigated. We collected chicken hypothalamus samples at seven time points in one light/dark cycle and performed long noncoding RNA (lncRNA), circular RNA (circRNA), and mRNA sequencing to detect biomarkers associated with circadian rhythm. We enhanced the comprehensive expression profiling of ncRNAs and mRNAs in the hypothalamus and found two gene sets (circadian rhythm and retinal metabolism) associated with the light/dark cycle. Noncoding RNA networks with circadian expression patterns were identified by differential expression and circadian analysis was provided that included 38 lncRNAs, 15 circRNAs, and 200 candidate genes. Three lncRNAs (ENSGALT00000098661, ENSGALT00000100816, and MSTRG.16980.1) and one circRNA (novel_circ_010168) in the ncRNA–mRNA regulatory network were identified as key molecules influencing circadian rhythm by regulating AOX1 in retinal metabolism. These ncRNAs were predicted to be related to pernicious anemia, gonadal, eye disease and other disorders in humans. Together, the findings of this study provide insights into the epigenetic mechanisms of circadian rhythm and reveal AOX1 as a promising target of circadian rhythm regulation. Full article

Recent studies have advanced our understanding of the pathophysiology of autoimmune gastritis, particularly its molecular aspects. The most noteworthy recent advancement lies in the identification of several candidate genes implicated in the pathogenesis of pernicious anemia through genome-wide association studies. These genes include PTPN22, PNPT1, HLA-DQB1, and IL2RA. Recent studies have also directed attention towards other genes such as ATP4A, ATP4B, AIRE, SLC26A7, SLC26A9, and BACH2 polymorphism. In-depth investigations have been conducted on lymphocytes and cytokines, including T helper 17 cells, interleukin (IL)-17A, IL-17E, IL-17F, IL-21, IL-19, tumor necrosis factor-α, IL-15, transforming growth factor-β1, IL-13, and diminished levels of IL-27. Animal studies have explored the involvement of roseolovirus and H. pylori in relation to the onset of the disease and the process of carcinogenesis, respectively. Recent studies have comprehensively examined the involvement of autoantibodies, serum pepsinogen, and esophagogastroduodenoscopy in the diagnosis of autoimmune gastritis. The current focus lies on individuals demonstrating atypical presentations of the disease, including those diagnosed in childhood, those yielding negative results for autoantibodies, and those lacking the typical endoscopic characteristics of mucosal atrophy. Here, we discuss the recent developments in this field, focusing on genetic predisposition, epigenetic modifications, lymphocytes, cytokines, oxidative stress, infectious agents, proteins, microRNAs, autoantibodies, serum pepsinogen, gastrin, esophagogastroduodenoscopy and microscopic findings, and the risk of gastric neoplasm. Full article

Background: Vitamin B12 (cobalamin CBL) is a water-soluble vitamin required to form hematopoietic cells (red blood cells, white blood cells, and platelets). It is involved in the process of synthesizing DNA and myelin sheath. Deficiencies of vitamin B12 and/or folate can cause megaloblastic anemia (macrocytic anemia with other features due to impaired cell division). Pancytopenia is a less frequent exordium of severe vitamin B12 deficiency. Vitamin B12 deficiency can also cause neuropsychiatric findings. In addition to correcting the deficiency, an essential aspect of management is determining the underlying cause because the need for additional testing, the duration of therapy, and the route of administration may differ depending on the underlying cause. Methods: Here, we present a series of four patients hospitalized for megaloblastic anemia (MA) in pancytopenia. All patients diagnosed with MA were studied for a clinic-hematological and etiological profile. Results: All the patients presented with pancytopenia and megaloblastic anemia. Vitamin B12 deficiency was documented in 100% of cases. There was no correlation between the severity of anemia and deficiency of the vitamin. Overt clinical neuropathy was present in none of the cases of MA, while subclinical neuropathy was seen in one case. The etiology of vitamin B12 deficiency was pernicious anemia in two cases and low food intake in the remaining cases. Conclusion: This case study emphasizes the role of vitamin B12 deficiency as a leading cause of pancytopenia among adults. Full article

Autoimmune metaplastic atrophic gastritis (AMAG) is associated with an increased risk of gastric neoplasms. This study aimed to systematically analyze the incidence rate of gastric cancer (GC), low-grade dysplasia (LGD) and type-1 gastric neuroendocrine tumor (gNETs) development in AMAG adults. Studies on AMAG patients reporting the incidence of gastric neoplasms was identified through a systematic search in PUBMED and EMBASE. Study quality was assessed using the Joanna Briggs Institute quality assessment tool. Incidence rates of GC, LGD and type-1 gNETs were examined by meta-analysis. Thirteen studies met eligibility criteria. Incidence rate of gastric cancer calculated from the pooled data was 0.14% per person-year in both single-center studies and national registration studies. Meta-analysis showed a relative risk of 11.05 (95% CI: 6.39–19.11) for gastric cancer development in AMAG patients. The calculated pooled gastric LGD and type-1 gNETs incidence rates were 0.52% and 0.83% per person-year, respectively. As for experience from our center, we presented three distinctive cases of gastric neoplasm arising from the background of AMAG. This study underscores the potential for malignant transformation of precancerous lesions and reiterates the importance of careful esophagogastroduodenoscopy screening. Full article

Vitamin B₁₂, also known as the anti-pernicious anemia factor, is an essential micronutrient totally dependent on dietary sources that is commonly integrated with food supplements. Four vitamin B₁₂ forms—cyanocobalamin, hydroxocobalamin, 5′-deoxyadenosylcobalamin, and methylcobalamin—are currently used for supplementation and, here, we provide an overview of their biochemical role, bioavailability, and efficacy in different dosage forms. Since the effective quantity of vitamin B₁₂ depends on the stability of the different forms, we further provide a review of their main reactivity and stability under exposure to various environmental factors (e.g., temperature, pH, light) and the presence of some typical interacting compounds (oxidants, reductants, and other water-soluble vitamins). Further, we explore how the manufacturing process and storage affect B₁₂ stability in foods, food supplements, and medicines and provide a summary of the data published to date on the content-related quality of vitamin B₁₂ products on the market. We also provide an overview of the approaches toward their stabilization, including minimization of the destabilizing factors, addition of proper stabilizers, or application of some (innovative) technological processes that could be implemented and contribute to the production of high-quality vitamin B₁₂ products. Full article

In this study, the synthesis parameters of the lotus root polysaccharide iron complex (LRPF) were determined and optimized by response surface methodology. Under the optimum preparation conditions, the pH of the solution was 9, the ratio of M (trisodium citrate): m (lotus root polysaccharide) was 0.45, the reaction time was 3 h. UV spectroscopy, thermogravimetry, FT-IR spectroscopy, X-ray diffraction, CD, and NMR were used for the characterization of the LRPF. LRPF has good stability and easily releases iron ions under artificial gastrointestinal conditions. LRPF exhibited antioxidant activity in vitro and can significantly improve the antioxidant activity in vivo. In addition, LRPF has a good effect in the treatment of iron deficiency anemia in model mice, impacts the gut microbiome, and reduces the iron deficiency-induced perniciousness by regulating steroid hormone biosynthesis. Therefore, LRPF can be used as a nutritional supplement to treat and prevent iron-deficiency anemia and improve human immunity. Full article

Gastric Intrinsic Factor (IF) is produced by the parietal cells of the stomach and secreted into the gastrointestinal tract where it ensures the active absorption of vitamin B12. We hypothesized that a small amount of IF ends up in the circulation and can be measured in serum. The aim of this study was to develop an assay for measuring human IF and to demonstrate its presence in serum. We designed a sensitive ELISA for measurement of human IF using a commercial monoclonal antibody and an in-house polyclonal antibody as capture and detecting antibody, respectively. Imprecision, accuracy, and linearity of the assay were examined. We established a reference interval based on serum samples from 240 healthy donors, and explored the daily IF fluctuations in 20 healthy subjects. Employing a prototype IF ELISA and size exclusion chromatography experiments, we demonstrated the presence of IF in human serum. In its final design, the IF ELISA has a measurement range of 0.2 to 50 pmol/L. The intra-assay and total imprecision were 7.9% and 15%, respectively. The 95% reference interval (18–65 years) was 1.7–11.6 pmol/L. No diurnal fluctuation or notable sex differences were observed. Our results suggest that the assay is capable of detecting and quantifying human IF in the circulation and may prove useful in the characterization of patients with impaired IF production. Full article

Pernicious anemia is still a neglected disorder in many medical contexts and is underdiagnosed in many patients. Pernicious anemia is linked to but different from autoimmune gastritis. Pernicious anemia occurs in a later stage of autoimmune atrophic gastritis when gastric intrinsic factor deficiency and consequent vitamin B₁₂ deficiency may occur. The multifaceted nature of pernicious anemia is related to the important role of cobalamin, which, when deficient, may lead to several dysfunctions, and thus, the proteiform clinical presentations of pernicious anemia. Indeed, pernicious anemia may lead to potentially serious long-term complications related to micronutrient deficiencies and their consequences and the development of gastric cancer and type 1 gastric neuroendocrine tumors. When not recognized in a timely manner or when pernicious anemia is diagnosed with delay, these complications may be potentially life-threatening and sometimes irreversible. The current review aimed to focus on epidemiology, pathogenesis, and clinical presentations of pernicious anemia in an attempt to look beyond borders of medical specialties. It aimed to focus on micronutrient deficiencies besides the well-known vitamin B₁₂ deficiency, the diagnostic approach for pernicious anemia, its long-term complications and optimal clinical management, and endoscopic surveillance of patients with pernicious anemia. Full article

Dysregulation of one-carbon metabolism affects a wide range of biological processes and is associated with a number of diseases, including cardiovascular disease, dementia, neural tube defects, and cancer. Accumulating evidence suggests that one-carbon metabolism plays an important role in COVID-19. The symptoms of long COVID-19 are similar to those presented by subjects suffering from vitamin B₁₂ deficiency (pernicious anemia). The metabolism of a cell infected by the SARS-CoV-2 virus is reshaped to fulfill the need for massive viral RNA synthesis, which requires de novo purine biosynthesis involving folate and one-carbon metabolism. Many aspects of host sulfur amino acid metabolism, particularly glutathione metabolism underlying antioxidant defenses, are also taken over by the SARS-CoV-2 virus. The purpose of this review is to summarize recent findings related to one-carbon metabolism and sulfur metabolites in COVID-19 and discuss how they inform strategies to combat the disease. Full article