Pernicious anemia

Pernicious anemia is a common cause of cobalamin deficiency-caused megaloblastic anemia in Hainan, China

BACKGROUND

Pernicious anemia (PA) is believed to be highly prevalent in Western countries but has rarely been reported in China. The study explores whether PA, an autoimmune disease, is an uncommon cause of cobalamin (vitamin B12) deficiency anemia in China.

METHODS

Clinical and hematological data were collected from 90 cobalamin deficiency-caused megaloblastic anemia (MA) patients between July 2014 and December 2021. Through anti-intrinsic factor antibody (IFA) and anti-parietal cell antibody (PCA) testing, PA was distinguished from other causes of cobalamin deficiency leading to MA. Meanwhile, 30 healthy controls (HCs) were included to estimate the positive rates of IFA and PCA.

RESULTS

Of the 30 HCs, only one tested positive for IFA, and all 30 tested negative for PCA. Among the 90 patients with cobalamin deficiency-caused MA, 76.7% were positive for IFA, and 47.8% were positive for PCA; a total of 76 patients (84.4%) were diagnosed with PA. The mean follow-up time was 41.0 ± 16.3 months. During the follow-up period, no case relapsed among the continuous cobalamin-supply treatment patients, while 24.4% of patients relapsed due to the interruption of maintenance cobalamin-supplement therapy (the median recurrence time was 54.0 ± 17.7 months).

CONCLUSIONS

The proportion of PA in cobalamin deficiency-caused MA patients in Hainan province was higher than 80%, which was more common than expected. Therefore, screening for IFA, PCA, endoscopic biopsy, and thyroid-related parameters are recommended for all cobalamin deficiency-caused MA patients. Furthermore, maintenance cobalamin-supplement therapy is important for PA patients.

Research status and hotspots of autoimmune gastritis: A bibliometric analysis

BACKGROUND

As an emerging potential risk factor for gastric cancer, autoimmune gastritis (AIG) has garnered increasing attention from researchers.

AIM

To analyze the research overview and popular topics in the field of AIG using bibliometrics.

METHODS

Relevant publications on AIG in the Web of Science Core Collection were collated, and data visualization and analysis of the number of publications, countries, institutions, journals, authors, keywords, and citations were performed using software such as VOSviewer, CiteSpace, and Scimago Graphic.

RESULTS

In total, 316 relevant articles were included in the analysis. From 2015 to 2022, the number of publications increased annually. The countries, institutions, authors, and journals with the highest number of publications in this field were Italy, Monash University, Toh BH, and Internal Medicine. The main keywords used in this field of research were pathogenesis, Helicobacter pylori, autoantibody, parietal cell antibody, atrophic gastritis, classification, diagnosis, autoimmune disease, risk, cancer, gastric cancer, vitamin B12 deficiency, and pernicious anemia. The following directions may be popular for future research: (1) The role of Helicobacter pylori in the pathogenesis of AIG; (2) diagnostic criteria for AIG and reference values for serum antibodies; (3) comorbidity mechanisms between AIG and other autoimmune diseases; (4) specific risks of AIG complicating gastric and other cancers; and (5) the role of vitamin B12 supplementation in patients with early-stage AIG.

CONCLUSION

This bibliometric analysis reported on popular topics and emerging trends in AIG, with diagnosis and prognosis being research hotspots in this field.

Redefining serological diagnostics with immunoaffinity proteomics

Serological diagnostics is generally defined as the detection of specific human immunoglobulins developed against viral, bacterial, or parasitic diseases. Serological tests facilitate the detection of past infections, evaluate immune status, and provide prognostic information. Serological assays were traditionally implemented as indirect immunoassays, and their design has not changed for decades. The advantages of straightforward setup and manufacturing, analytical sensitivity and specificity, affordability, and high-throughput measurements were accompanied by limitations such as semi-quantitative measurements, lack of universal reference standards, potential cross-reactivity, and challenges with multiplexing the complete panel of human immunoglobulin isotypes and subclasses. Redesign of conventional serological tests to include multiplex quantification of immunoglobulin isotypes and subclasses, utilize universal reference standards, and minimize cross-reactivity and non-specific binding will facilitate the development of assays with higher diagnostic specificity. Improved serological assays with higher diagnostic specificity will enable screenings of asymptomatic populations and may provide earlier detection of infectious diseases, autoimmune disorders, and cancer. In this review, we present the major clinical needs for serological diagnostics, overview conventional immunoassay detection techniques, present the emerging immunoassay detection technologies, and discuss in detail the advantages and limitations of mass spectrometry and immunoaffinity proteomics for serological diagnostics. Finally, we explore the design of novel immunoaffinity-proteomic assays to evaluate cell-mediated immunity and advance the sequencing of clinically relevant immunoglobulins.

Update on Serum Biomarkers in Autoimmune Atrophic Gastritis

BACKGROUND

Autoimmune atrophic gastritis (AAG) is a persistent, corpus-restricted immune-mediated destruction of the gastric corpus oxyntic mucosa with reduced gastric acid and intrinsic factor secretion, leading to iron deficiency and pernicious anemia as a consequence of iron and cobalamin malabsorption. Positivity toward parietal cell (PCA) and intrinsic factor (IFA) autoantibodies is very common. AAG may remain asymptomatic for many years, thus making its diagnosis complex and often delayed. Due to the increased risk of gastric neoplasms, a timely diagnosis of AAG is clinically important.

CONTENT

The gold standard for AAG diagnosis is histopathological assessment of gastric biopsies obtained during gastroscopy, but noninvasive, preendoscopic serological screening may be useful in some clinical scenarios. Serum biomarkers for AAG may be divided into 2 groups: gastric autoimmunity-related biomarkers, such as PCA and IFA, and gastric corpus atrophy/reduced gastric acid secretion-related biomarkers, such as serum gastrin and pepsinogens. The present review focuses on the clinical significance and pitfalls of serum biomarkers related to gastric autoimmunity and gastric corpus atrophy, including some discussion of analytical methods.

SUMMARY

Serum assays for PCA, IFA, gastrin, and pepsinogen I show good diagnostic accuracy for noninvasive diagnostic work-up of AAG. Diagnostic performance may increase by combining >1 of these tests, overcoming the problem of seronegative AAG. However, appropriately designed, comparative studies with well-characterized patient cohorts are needed to better define the reliability of these biomarkers in the diagnosis of patients with AAG. Currently, positive serum tests should always be followed by the state-of-art diagnostic test, that is, histopathological assessment of gastric biopsies obtained during gastroscopy to definitively confirm or rule out AAG and eventually neoplastic complications.

Imaging Aspects of Toxic and Metabolic Myelopathies

Metabolic and toxic myelopathies usually occurs due to several different causes. Metabolic myelopathy usually occurs due to deficiency of a nutrient, such as vitamin B12. Toxic myelopathy occurs secondary to the exposure to an external toxic agent. Although they may have a difficult diagnosis, determination of the specific cause of myelopathy is of utmost importance, because many causes are amenable to treatment. Although they have many clinical, electrophysiologic, and neuropathologic similarities, imaging may aid in the suspicion of toxic or metabolic myelopathy. The aim of this article, is to review the imaging features of the main toxic and metabolic myelopathies.

Elderly Patient With Hematological and Neurological Manifestations of Undetermined Origin: A Diagnostic Dilemma of Pernicious Anemia

Pernicious anemia (PA) is a chronic inflammatory destructive disease of parietal cells of predominantly the gastric fundus. It leads to vitamin B12 (cobalamin) deficiency secondary to a deficiency of intrinsic factors. Despite the medical advances nowadays, diagnosing PA can be challenging. This report highlights a neglected case of PA with ongoing subacute combined degeneration of the cord (SCDS) in an elderly patient. An 86-year-old lady with multiple comorbidities was referred to the hematology outpatient clinic for refractory anemia for the last two months. At first, her general practitioner (GP) treated her as a case of anemia of chronic disease but without improvement. Her initial clinical assessment revealed hematological and neurological manifestations of undetermined origin, including global weakness, hypertonia, and hyperreflexia with sensory deficits, especially in the lower limbs. On investigation, the hemoglobin level was 9 g/dL with high indirect bilirubinemia and lactate dehydrogenase (LDH). Despite the normal mean corpuscular volume (MCV) and peripheral blood smear, positive anti-intrinsic factor and parietal cell antibodies tests were subsequently reported, suggesting the diagnosis of PA. As a result, she was commenced on lifelong parenteral cobalamin replacement therapy. On follow-up visits of three months, she illustrated a clinical recovery in fatigability and paranesthesia. As expected, the laboratory parameters revealed a rise in hemoglobin level (11 g/dL) and serum vitamin B12 (418 pg/mL). However, she remained bedridden with spastic limbs. Clinicians should have a high index of suspicion since PA is a rare disease with variable clinical presentations. The optimal management approach is by a multidisciplinary care team of internists, neurologists, gastroenterologists, and hematologists.

Analysis of a series of Italian APECED patients with autoimmune hepatitis and gastro-enteropathies

Introduction

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a rare monogenic disease determined by biallelic mutations in AIRE gene, which encodes a transcription factor essential for central immune tolerance. Classic diagnosis is determined by the presence of two of the main APECED clinical diseases: chronic mucocutaneous candidiasis, chronic hypoparathyroidism, and Addison's disease. Non-endocrine autoimmunity, involving the liver, intestine, eyes, and kidneys, is generally reported in a minority of European patients, while American APECED patients have a higher tendency of developing organ-specific non-endocrine manifestations early in life. This observation led to the revision of the diagnostic criteria to permit earlier diagnosis based on the appearance of one classic triad symptom or one non-classical manifestation at a young age in the presence of IFNωAbs or AIRE mutations (Ferre-Lionakis criteria).

Patients and methods

We analyzed the clinical, genetic, and autoantibody (Ab) profiles in a series of 14 pediatric Italian APECED patients with gastrointestinal manifestations (seven male and seven female patients). Ten patients presented hepatitis (APECED-associated hepatitis (APAH)), while seven were affected by constipation, diarrhea, and malabsorption. Four patients had developed APAH before classic triad symptoms.

Results

Based on the age of appearance of non-endocrine manifestations including APAH and gastro-enteropathy, the Ferre-Lionakis criteria would have allowed an expedited diagnosis in 11/14 patients. Abs to tryptophan hydroxylase (TPHAb) and hepatic aromatic l-amino acid decarboxylase (AADC) were significantly associated with APECED patients of the present series. Abs to cP4501A2 were detectable in the serum of 4/8 patients with APAH, and Abs to cP4502A6 were detectable in 3/8 patients. AADC Abs tested positive in 5/7 patients, which is indicative of gastrointestinal dysfunction in APECED and TPHAb in 5/7 patients with gastrointestinal dysfunction. IFNAb was significantly associated with the syndrome.

Conclusion

Although Ferre-Lionakis expanded criteria applied to the American cohorts of APECED patients would require validation in independent large cohorts of European patients, the results of this study emphasize the importance to evaluate the presence and the age of appearance of APAH and autoimmune enteropathy even in European cohorts for an earlier APECED diagnosis. An earlier APECED diagnosis would also allow the prevention of episodes of life-threatening hypocalcemic seizures and adrenal crisis, which are the main manifestations of undiagnosed APECED.

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.

The inorganic chemistry of the cobalt corrinoids - an update

The inorganic chemistry of the cobalt corrinoids, derivatives of vitamin B₁₂, is reviewed, with particular emphasis on equilibrium constants for, and kinetics of, their axial ligand substitution reactions. The role the corrin ligand plays in controlling and modifying the properties of the metal ion is emphasised. Other aspects of the chemistry of these compounds, including their structure, corrinoid complexes with metals other than cobalt, the redox chemistry of the cobalt corrinoids and their chemical redox reactions, and their photochemistry are discussed. Their role as catalysts in non-biological reactions and aspects of their organometallic chemistry are briefly mentioned. Particular mention is made of the role that computational methods - and especially DFT calculations - have played in developing our understanding of the inorganic chemistry of these compounds. A brief overview of the biological chemistry of the B₁₂-dependent enzymes is also given for the reader's convenience.

Pernicious Anemia Presenting as a Mimicker of Thrombotic Thrombocytopenic Purpura

A 52-year-old woman with no significant past medical history presented to the emergency room (ER) with nonspecific systemic symptoms, including fatigue, dyspnea on exertion, easy bruising, and palpitations. She was found to have significant pancytopenia. Hemolytic anemia, thrombocytopenia, and elevated PLASMIC score (6, High risk; PLASMIC = Platelet count; combined hemoLysis variable; absence of Active cancer; absence of Stem-cell or solid-organ transplant; MCV; INR; Creatinine) score at the time of presentation led to a concern for thrombotic thrombocytopenic purpura (TTP). Therapeutic plasma exchange (TPE) was deferred pending additional investigation. Workup revealed the true diagnosis of severe B12 deficiency, which would not have benefited from TPE and instead would have placed the patient at risk for harm, making the decision to defer treatment the correct and judicious approach. This is a case where anchoring on lab results may result in reaching the incorrect diagnosis. This case reminds clinicians of the importance of creating a broad differential and ensuring thorough history-taking is done for all patients.

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.

Autoimmune conditions and pancreatic cancer risk in older American adults

Pancreatic cancer (PC) is highly fatal, and its incidence is increasing in the United States. Population-based registry studies suggest associations between a few autoimmune conditions and PC risk, albeit based on a relatively small number of cases. We conducted a population-based, nested case-control study to examine the associations between autoimmune conditions and PC risk within the Surveillance, Epidemiology, and End Results Program (SEER)-Medicare population. Incident primary malignant PC cases (n = 80 074) were adults ≥66 years and diagnosed between 1992 and 2015. Controls (n = 320 296) were alive at the time cases were diagnosed and frequency-matched to cases (4:1 ratio) by age, sex, and year of diagnosis. We used multivariable-adjusted, unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for 45 autoimmune conditions identified from Medicare claims. Eight autoimmune conditions including ankylosing spondylitis (OR = 1.45; 95% CI: 1.14-1.84), Graves' disease (OR = 1.18; 95% CI: 1.03-1.34), localized scleroderma (OR = 1.27; 95% CI: 1.06-1.52), pernicious anemia (OR = 1.08; 95% CI: 1.02-1.14), primary sclerosing cholangitis (OR = 1.37; 95% CI: 1.18-1.59), pure red cell aplasia (OR = 1.31; 95% CI: 1.16-1.47), type 1 diabetes (OR = 1.11; 95% CI: 1.07-1.15), and ulcerative colitis (OR = 1.18; 95% CI: 1.07-1.31) were associated with increased PC risk (false discovery rate-adjusted P values <.10). In subtype analyses, these conditions were associated with pancreatic ductal adenocarcinoma, whereas only ulcerative colitis was associated with pancreatic neuroendocrine tumors. Our results support the hypothesis that autoimmune conditions may play a role in PC development.

Risk factors for gastric cancer: A comprehensive analysis of observational studies

Background

Multifarious factors have a causal relationship with gastric cancer (GC) development. We conducted a comprehensive analysis to evaluate the strength of the evidence examining non-genetic risk factors for gastric cancer.

Methods

PubMed, Web of Science, and the Cochrane Library were searched from inception to November 10, 2021 to identify meta-analyses of observational studies examining the association between environmental factors and GC risk. For each meta-analysis, the random effect size, 95% confidence interval, heterogeneity among studies, and evidence of publication bias were assessed; moreover, the evidence was graded using predefined criteria, and the methodological quality was evaluated using AMSTAR 2.

Results

A total of 137 associations were examined in 76 articles. Among these meta-analyses, 93 associations yielded significant estimates (p < 0.05). Only 10 associations had strong epidemiologic evidence, including 2 risk factors (waist circumference and bacon), and 8 protective factors (dietary total antioxidant capacity, vegetable fat, cruciferous vegetable, cabbage, total vitamin, vitamin A, vitamin C, and years of fertility); 26 associations had moderate quality of evidence; and the remaining 57 associations were rated as weak. Ninety-four (68.61%) associations showed significant heterogeneity. Twenty-five (18.25%) associations demonstrated publication bias.

Conclusions

In this comprehensive analysis, multiple associations were found between environmental factors and GC with varying levels of evidence. Healthy dietary habits and lifestyle patterns could reduce the risk for GC. However, further high-quality prospective studies are still necessary to draw more definitive conclusions.

The Diagnostic Value of Anti-Parietal Cell and Intrinsic Factor Antibodies, Pepsinogens, and Gastrin-17 in Corpus-Restricted Atrophic Gastritis

We aimed to determine the diagnostic value of anti-parietal cell antibodies (anti-PCA), anti-intrinsic factor antibodies (anti-IFA), pepsinogen ratio (PGI/II), and gastrin-17 (G-17) in corpus-restricted atrophic gastritis (CRAG) detected by ELISA (Inova, Biohit). Our study compared 29 CRAG cases against 58 age- and sex-matched controls with mild or no atrophy. Anti-PCA and anti-IFA positive cutoff values were ≥25 units for both. PGI/II value <3 was considered characteristic for atrophy; positive cutoff values for G-17 and anti-H. pylori IgG were >5 pg/L and >30 EIU. Anti-PCA was positive in 65.5% For CRAG cases and 13.8% of the controls (p < 0.0001), anti-IFA was positive in 13.8% and 0% (p = 0.01), respectively. Decreased pepsinogen levels were present in 79.3% of CRAG cases and 10.3% of the controls (p < 0.0001). PGI/II ratio was the best single biomarker, with sensitivity = 79%, specificity = 90%, and AUC 0.90. The combined use of PGI/II and anti-PCA resulted in AUC 0.93 for detecting CRAG. Our study suggests that the best combination of non-invasive biomarkers for detecting CRAG is PGI/II with anti-PCA. The addition of G-17 and anti-IFA is of little utility in clinical application.

A Rare Presentation of Pernicious Anemia Manifesting as Disseminated Intravascular Coagulation

Pernicious anemia is an autoimmune disorder that is characterized by the presence of autoantibodies to intrinsic factor and parietal cells which results in the inability to absorb vitamin B12. It is the most common manifestation of vitamin B12 deficiency and accounts for 20-50% of cases. Disseminated intravascular coagulation (DIC) is a clinical condition that is a complication of another process which causes the activation of coagulation. A 63-year-old female with a history of hypothyroidism presented with a 1-month history of worsening fatigue, intermittent epigastric pain, nausea, vomiting, and diarrhea. Initial laboratory findings showed severe anemia and macrocytosis with a hemoglobin of 4.3 g/dL and a mean corpuscular volume (MCV) of 138 fL. There was also a significant elevation of the D-dimer, lactate dehydrogenase (LDH), and creatinine. She received three units of packed red blood cells (pRBCs) and fluid resuscitation. A vitamin B12 level was obtained which revealed a severe vitamin B12 deficiency (< 150 pg/mL). Additional workup showed seropositivity for anti-parietal cell antibodies and intrinsic factor blocking antibodies, and an esophagogastroduodenoscopy (EGD) biopsy yielded histologic findings consistent with autoimmune gastritis. She was treated acutely with daily intramuscular B12 injections with improvement in hematologic derangements and symptomatology. Arrested erythropoiesis can lead to apoptosis and the high proliferation of immature erythroblasts results in cells that are more susceptible to impaired deoxyribonucleic acid (DNA) synthesis and results in denatured DNA. Pernicious anemia manifesting as DIC has yet to be described in the literature. Here we describe an interesting case of pernicious anemia manifesting as early DIC resulting from arrest of erythropoiesis evidenced by the international society on thrombosis and hemostasis score of 5, diagnostic for DIC. Early recognition and treatment of this reversible etiology of DIC is essential to the improvement of patient outcomes.

Iron deficiency and soil-transmitted helminth infection: classic and neglected connections

Beyond participating in the oxygen transport by red blood cells, iron is an essential micronutrient and contributes to different physiological pathways and processes, such as cell proliferation, DNA repair, and other homeostatic functions. Iron deficiency affects millions of people, especially children and pregnant women. The consequences of iron deficiency are diverse, including inadequate child development, impaired cognition, and reduced productivity. Several factors contribute to iron deficiency, such as iron-poor diet, genetic factors, and infection with soil-transmitted helminths (STHs), especially roundworms (Ascaris lumbricoides), hookworms (Necator americanus and Ancylostoma duodenale), and whipworms (Trichuris trichiura). This review updates and summarizes the role of STHs as drivers of iron deficiency. Also, the poorly explored connections between STH infection, geophagia (a pica manifestation), immune response, and iron deficiency are discussed, highlighting how iron deficiency may act as a risk factor for infections by STHs, in addition to being a consequence of intestinal parasitic infections. Finally, strategies for control and management of iron deficiency and STH infection are described.

Rare case of pernicious anaemia from a university hospital of Nepal: A case report

Introduction

Pernicious Anaemia is a rare autoimmune disorder prevalent among 0.1% of the general population and is characterised by decreased cobalamin absorption. This condition is overlooked because of its rarity, insidious onset of non-specific symptoms and clinically asymptomatic state. Elevated serum intrinsic factor antibody level along with reduced Vitamin B12 level confirms the diagnosis.

Case presentation

Pallor and abdominal tenderness was present. Haematological investigations showed elevated platelet count, elevated Mean Cell Volume reduced haemoglobin level(11.4 g/dl), reduced Vitamin B12 and high serum intrinsic factor antibody level. Serum parietal cell antibody was positive. The patient responded well to parenteral Vitamin B12.

Discussion

In Pernicious anaemia, serum intrinsic factor antibody and parietal cell antibody are high which are responsible for reduced Vitamin B12 absorption. Studies have also shown positive correlation between H pylori and Pernicious Anaemia. Neurological symptoms are less common but may present as paraesthesia, changes in gait or spasticity due to peripheral neuropathy. It is also associated with autoimmune diseases. Untreated pernicious anaemia can lead to neurological and gastrointestinal complications.

Conclusion

Pernicious Anaemia is an overlooked condition because of its insidious onset of non-specific symptoms, clinically asymptomatic state, rarity and therefore timely diagnosis of Pernicious Anaemia still remains a challenge.

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Presentation of a case of Pernicious Anaemia that is uncommon in the Asian population.

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Incidence correlated with Helicobacter pylori infection.

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Presence of autoantibodies against both intrinsic factors and parietal cells specific to the disease.

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Disease entity requiring correction by replacement with parenteral or oral Vitamin B12.

Relationship between active Helicobacter pylori infection and anemia, iron deficiency, iron deficiency anemia: A cross‐sectional study in a sub‐Saharan setting

Background and Aim

There have been contradictory reports about the association between Helicobacter pylori infection and iron deficiency anemia (IDA). Based on the high frequency of H. pylori infection in Cameroon, we have evaluated the frequency of H. pylori infection as the cause of anemia, and IDA among dyspeptic patients in Cameroon.

Methods

This cross‐sectional study enrolled 842 dyspeptic patients (472 women and 370 men) in two reference hospitals in Douala‐Cameroon. Each participant gave a written consent, and the study was approved by the National Ethical Committee. Erythroid‐related indices and markers of iron deficiency (ID) measurement were done for each participant as well as H. pylori detection. Data were analyzed using SSPS statistical package.

Results

The prevalence of anemia, ID, IDA, and H. pylori infection was 65.08%, 31.47%, 25.65%, and 80.88%, respectively. H. pylori infected individuals had a significantly lower mean value of hemoglobin (P = 0.01), hematocrit (P = 0.04), ferritin (P = 0.03) and coefficient of transferrin saturation (CTS) levels (P = 0.04) and a significantly higher mean value of mean corpuscular hemoglobin concentration (MCHC) (P = 0.02). Compared with H. pylori non‐infected participants, H. pylori infected patients were 1.2938 (95% confidence interval [CI]: 0.9087–1.8421), 1.1851 (95% CI: 0.8122–1.7292), and 1.5636 (95% CI: 1.0206–2.3953) times at higher risk to develop anemia, ID, and IDA, respectively. A significant relationship was found between H. pylori infection and IDA (P = 0.04 and 0.04 for crude and age/sex‐adjusted, respectively).

Conclusion

H. pylori infection seems to be associated with anemia, and IDA among dyspeptic patients in our milieu.

Vitamin B12 coordinates ileal epithelial cell and microbiota functions to resist Salmonella infection in mice

Deprivation of vitamin B12 (VB12) is linked to various diseases, but the underlying mechanisms in disease progression are poorly understood. Using multiomic approaches, we elucidated the responses of ileal epithelial cells (iECs) and gut microbiome to VB12 dietary restriction. Here, VB12 deficiency impaired the transcriptional and metabolic programming of iECs and reduced epithelial mitochondrial respiration and carnitine shuttling during intestinal Salmonella Typhimurium (STm) infection. Fecal microbial and untargeted metabolomic profiling identified marked changes related to VB12 deficiency, including reductions of metabolites potentially activating mitochondrial β-oxidation in iECs and short-chain fatty acids (SCFAs). Depletion of SCFA-producing microbes by streptomycin treatment decreased the VB12-dependent STm protection. Moreover, compromised mitochondrial function of iECs correlated with declined cell capability to utilize oxygen, leading to uncontrolled oxygen-dependent STm expansion in VB12-deficient mice. Our findings uncovered previously unrecognized mechanisms through which VB12 coordinates ileal epithelial mitochondrial homeostasis and gut microbiota to regulate epithelial oxygenation, resulting in the control of aerobic STm infection.

Pathophysiology and therapeutic management of anemia in gastrointestinal disorders

INTRODUCTION

Anemia is a common complication of gastrointestinal (GI) disorders, with a prevalence up to 60% in celiac disease (CeD) and inflammatory bowel disease (IBD). Iron deficiency anemia (IDA) is the most prevalent form of anemia in these conditions, but chronic inflammation and vitamin B12 deficiency represent other common contributing mechanisms, especially in IBD.

AREAS COVERED

We discuss the pathogenesis of anemia in various medical GI disorders, the sometime problematic distinction between IDA, anemia of inflammation (AI) and the association of the two, and therapeutic and preventive measures that can be useful for the management of anemia in GI disorders. Unfortunately, with the exception of IDA and AI in IBD, large RCT concerning the treatment of anemia in GI disorders are lacking.

EXPERT OPINION

Anemia management strategies in GI disorders are outlined, with a focus on the main prevention, diagnostic, and therapeutic measures. Specific problems and situations such as the role of gluten-free diet for IDA treatment in CeD, the choice between oral and parenteral supplementation of iron or vitamin B12 in carential anemias, the use of endoscopic procedures to stop bleeding in intestinal angiodysplasia and preventive/treatment strategies for NSAID-associated GI bleeding are discussed.

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.

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.

Pernicious Anemia: The Hematological Presentation of a Multifaceted Disorder Caused by Cobalamin Deficiency

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.

Serum B12, homocysteine, and anti-parietal cell antibody levels in children with autism

AIMS

To compare vitamin B12, homocysteine, and anti-parietal cell antibody (APCA) levels between children with ASD and controls, paired in terms of age, sex, and socioeconomic level.

METHODS

The research group consisted of 69 children, 36 with ASD and 33 controls. The severity of ASD was determined using the Childhood Autism Rating Scale (CARS). Serum vitamin B12, homocysteine and human anti-parietal cell levels were analysed using enzyme-linked immunosorbent assay.

RESULTS

The serum vitamin B12 and homocysteine levels in children with ASD were lower than in the control group, but there was no significant difference in terms of APCA levels.

CONCLUSIONS

Deficiencies in micronutrients, such as B12, may play a role in the pathogenesis and clinical symptoms of autism. However, it is believed that these parameters should be analysed in a wider population to clarify their effect on the aetiology of ASD.KEY POINTWe hypothesised that low levels of vitamin B12 and homocysteine levels reported in previous studies might be associated with APCA levels.The homocysteine and B12 levels were found to be significantly lower in children with ASD. There was no significant difference in serum APCA levels.No significant relationship was found between B12 levels and APCA.Given all these findings, it can be stated that vitamin B12 deficiency is not associated with an absorption-related mechanism due to the presence of APCA.Deficiencies in micronutrients, such as B12, may play a role in the pathogenesis and clinical symptoms of autism.In future studies, it will be beneficial to investigate other mechanisms that may cause vitamin B12 deficiency.

Autoimmune polyglandular syndrome type 3: A case report of an unusual presentation and literature review

Autoimmune polyglandular syndromes (APS) are rare disorders characterized by auto-destruction of endocrine and non-endocrine organs by organ-specific antibody-directed T-lymphocytic infiltration. This case highlights a 29-year-old Caucasian man with vitiligo found to have significant neurological abnormalities in the setting of newly diagnosed pernicious anemia and thyroid autoimmune disease.

Dietary Intake and Status of Vitamin B12 in Slovenian Population

Vitamin B12 deficiency poses a health concern, especially in vulnerable populations. Dietary vitamin B12 intake was obtained by two 24 h dietary recalls and food propensity questionnaires in a representative Slovenian cross-sectional food consumption survey, SI.Menu (n = 1248 subjects; 10-74 years). For a subgroup of 280 participants, data on serum vitamin B12 were available through the Nutrihealth study. The estimated usual population-weighted mean daily vitamin B12 intakes were 6.2 µg (adults), 5.4 µg (adolescents), and 5.0 µg (elderly). Lower intakes were observed in females. Inadequate daily vitamin B12 intake (<4 µg) was detected in 37.3% of adolescents, 31.7% of adults, and 58.3% elderlies. The significant predictors for inadequate daily vitamin B12 intake were physical activity score in all age groups, sex in adolescents and adults, financial status and smoking in elderly, and employment in adults. Meat (products), followed by milk (products), made the highest vitamin B12 contribution in all age groups. In adolescents, another important vitamin B12 contributor was cereals. The mean population-weighted serum vitamin B12 levels were 322.1 pmol/L (adults) and 287.3 pmol/L (elderly). Low serum vitamin B12 concentration (<148 nmol/L) and high serum homocysteine (>15 µmol/L) were used as criteria for vitamin B12 deficiency. The highest deficiency prevalence was found in elderlies (7.0%), particularly in males (7.9%). Factors associated with high serum homocysteine were also investigated. In conclusion, although vitamin B12 status was generally not critical, additional attention should be focused particularly to the elderly.

Two Distinct Etiologies of Gastric Cancer: Infection and Autoimmunity

Gastric cancer is a leading cause of mortality worldwide. The risk of developing gastric adenocarcinoma, which comprises >90% of gastric cancers, is multifactorial, but most associated with Helicobacter pylori infection. Autoimmune gastritis is a chronic autoinflammatory syndrome where self-reactive immune cells are activated by gastric epithelial cell autoantigens. This cause of gastritis is more so associated with the development of neuroendocrine tumors. However, in both autoimmune and infection-induced gastritis, high risk metaplastic lesions develop within the gastric mucosa. This warrants concern for carcinogenesis in both inflammatory settings. There are many similarities and differences in disease progression between these two etiologies of chronic gastritis. Both diseases have an increased risk of gastric adenocarcinoma development, but each have their own unique comorbidities. Autoimmune gastritis is a primary cause of pernicious anemia, whereas chronic infection typically causes gastrointestinal ulceration. Both immune responses are driven by T cells, primarily CD4⁺ T cells of the IFN-γ producing, Th1 phenotype. Neutrophilic infiltrates help clear H. pylori infection, but neutrophils are not necessarily recruited in the autoimmune setting. There have also been hypotheses that infection with H. pylori initiates autoimmune gastritis, but the literature is far from definitive with evidence of infection-independent autoimmune gastric disease. Gastric cancer incidence is increasing among young women in the United States, a population at higher risk of developing autoimmune disease, and H. pylori infection rates are falling. Therefore, a better understanding of these two chronic inflammatory diseases is needed to identify their roles in initiating gastric cancer.

Vitamin B12 status in health and disease: a critical review. Diagnosis of deficiency and insufficiency - clinical and laboratory pitfalls

Vitamin B₁₂ (cobalamin) is an essential cofactor for two metabolic pathways. It is obtained principally from food of animal origin. Cobalamin becomes bioavailable through a series of steps pertaining to its release from dietary protein, intrinsic factor-mediated absorption, haptocorrin or transcobalamin-mediated transport, cellular uptake, and two enzymatic conversions (via methionine synthase and methylmalonyl-CoA-mutase) into cofactor forms: methylcobalamin and adenosylcobalamin. Vitamin B₁₂ deficiency can masquerade as a multitude of illnesses, presenting different perspectives from the point of view of the hematologist, neurologist, gastroenterologist, general physician, or dietician. Increased physician vigilance and heightened patient awareness often account for its early presentation, and testing sometimes occurs during a phase of vitamin B₁₂ insufficiency before the main onset of the disease. The chosen test often depends on its availability rather than on the diagnostic performance and sensitivity to irrelevant factors interfering with vitamin B₁₂ markers. Although serum B₁₂ is still the most commonly used and widely available test, diagnostics by holotranscobalamin, serum methylmalonic acid, and plasma homocysteine measurements have grown in the last several years in routine practice. The lack of a robust absorption test, coupled with compromised sensitivity and specificity of other tests (intrinsic factor and gastric parietal cell antibodies), hinders determination of the cause for depleted B₁₂ status. This can lead to incorrect supplementation regimes and uncertainty regarding later treatment. This review discusses currently available knowledge on vitamin B₁₂, informs the reader about the pitfalls of tests for assessing its deficiency, reviews B₁₂ status in various populations at different disease stages, and provides recommendations for interpretation, treatment, and associated risks. Future directions for diagnostics of B₁₂ status and health interventions are also discussed.

Use of hyperbaric oxygenation as an adjunctive treatment for severe pernicious anaemia in a bloodless medicine patient

Severe anaemia in patients who cannot receive blood transfusion is an indication for the use of hyperbaric oxygen therapy (HBO). Most reports of the use of HBO for anaemia involve patients with acute blood loss. This report details a case of HBO used for a patient with severe pernicious anaemia. A 35-year-old Jehovah's Witnesses believer presented to a hospital with fatigue, dyspnoea and haemoglobin of 26 g/L. She was diagnosed with pernicious anaemia. As she could not receive blood transfusion due to her religious beliefs, vitamin B₁₂ supplementation and HBO were administered and resulted in significant improvement in her condition. The mechanisms of action of HBO, including increased systemic plasma oxygenation, can alleviate signs and symptoms of anaemia regardless of its aetiology. HBO administration can greatly enhance the plasma arterial oxygen content, leading to clinical improvement in patients with anaemia who cannot receive blood transfusion.

PANCYTOPENIA SECONDARY TO AUTOIMMUNE VITAMIN B12 DEFICIENCY IN GRAVES DISEASE

Objective

To describe a case of Graves disease (GD) and coexistent pancytopenia associated with autoimmune vitamin B₁₂ deficiency. While thyrotoxicosis and antithyroid drugs can cause pancytopenia, other autoimmune conditions such as vitamin B₁₂ deficiency can occur, leading to severe anemia and pancytopenia.

Methods

A 19-year-old female with GD treated with methimazole presented with thyrotoxicosis and evidence of pancytopenia. Diagnostic studies included a complete blood cell count, peripheral blood smears, thyroid function tests, and a bone marrow biopsy.

Results

White blood cells were 2.4 × 10⁹ cells/L (reference range [RR] is 3.4 to 9.6 × 10⁹ cells/L), hemoglobin was 7.9 g/dL (RR is 11.6 to 15.0 g/dL), neutrophil count was 1.2 × 10⁹ cells/L, and platelets were 84 × 10⁹ cells/L (RR is 157 to 371 × 10⁹ cells/L). Thyroid-stimulating hormone was <0.01 mIU/L (RR is 0.50 to 4.30 mIU/L), free thyroxine was 3.7 ng/dL (RR is 1.0 to 1.6 ng/dL), and total triiodothyronine was 221 ng/dL (RR is 91 to 218 ng/dL). Due to suspicion for drug-induced pancytopenia, methimazole was discontinued. Three days later, she was hospitalized for a syncopal episode with a further decline in hemoglobin to 6.7 g/dL, neutrophils to 0.68 × 10⁹ cells/L, and platelets to 69 × 10⁹ cells/L. Bone marrow biopsy findings showing marrow hypercellularity and hypersegmented neutrophils suggested vitamin B₁₂ deficiency. Vitamin B₁₂ was <70 ng/L (RR is 180 to 914 ng/L). Intramuscular vitamin B₁₂ injections were initiated, and pancytopenia resolved within 1 month.

Conclusion

Although rarely described in the literature, autoimmune vitamin B₁₂ deficiency can be missed as an underlying etiology for pancytopenia in patients with GD. The clinical picture can be further confounded when these patients are treated with antithyroid drugs known to cause bone marrow suppression.

Gastrin Staining in Inflamed Stomach Biopsies Labeled as "Antral" Rarely Detects Atrophic Gastritis

OBJECTIVES

Autoimmune metaplastic atrophic gastritis (AMAG) is an underrecognized entity, especially in its early stage. This study assessed whether the use of gastrin immunohistochemistry would increase sensitivity for diagnosing early AMAG.

METHODS

Three-hundred gastric biopsies were prospectively stained for gastrin by immunohistochemistry. Inclusion criteria included well-oriented gastric mucosa with mucus glands and minimal plasma cell infiltrate not suspected to represent pyloric metaplasia. Patient age, sex, designated location of biopsy, presence or absence of intestinal metaplasia, and clinical information were not criteria. Any case with absence of gastrin-positive endocrine cells reflexed to chromogranin immunohistochemistry. Maloriented biopsies or cases with current Helicobacter infection were excluded.

RESULTS

The 298-patient study cohort comprised 222 females (mean age, 47 years; range, 16-80 years) and 76 males (mean age, 49 years; range, 7-80 years). Biopsies were designated as "antral/antral nodules" (61%), and the rest were labeled "gastric/random stomach" (39%). Nine cases (3%) exhibited absence of gastrin-positive endocrine cells; one of those showed endocrine cell hyperplasia by chromogranin staining.

CONCLUSIONS

Pathologists should be aware of the histologic features of early AMAG and meticulously analyze tissue regardless of specimen labeling. Gastrin immunostain is a supplemental diagnostic tool when encountering inflamed antral-appearing specimens.

Autoimmune atrophic gastritis: The role of Helicobacter pylori infection in children

BACKGROUND

Autoimmune atrophic gastritis (AIG) is very rare in children. Despite a better understanding of histopathologic changes and serological markers in this disease, underlying etiopathogenic mechanisms and the effect of Helicobacter pylori (H pylori) infection are not well known. We aimed to investigate the relation between AIG and H pylori infection in children.

MATERIALS AND METHODS

We evaluated the presence of AIG and H pylori infection in fifty-three patients with positive antiparietal cell antibody (APCA). Demographic data, clinical symptoms, laboratory and endoscopic findings, histopathology, and presence of H pylori were recorded.

RESULTS

The children were aged between 5 and 18 years, and 28 (52.8%) of them were male. Mean age was 14.7 ± 2.6 years (median: 15.3; min-max: 5.2-18), and 10 (18.8%) of them had AIG confirmed by histopathology. In the AIG group, the duration of vitamin B12 deficiency was longer (P = .022), hemoglobin levels were lower (P = .018), and APCA (P = .039) and gastrin (P = .002) levels were higher than those in the non-AIG group. Endoscopic findings were similar between the two groups. Intestinal metaplasia was higher (P = .018) in the AIG group. None of the patients in the AIG group had H pylori infection (P = .004). One patient in the AIG group had enterochromaffin-like cell hyperplasia.

CONCLUSIONS

Our results show that, in children, H pylori infection may not play a role in AIG. AIG could be associated with vitamin B12 deficiency, iron deficiency, and APCA positivity in children. APCA and gastrin levels should be investigated for the early diagnosis of AIG and intestinal metaplasia.

Identification of Gastritis Subtypes by Convolutional Neuronal Networks on Histological Images of Antrum and Corpus Biopsies

Background: Gastritis is a prevalent disease and commonly classified into autoimmune (A), bacterial (B), and chemical (C) type gastritis. While the former two subtypes are associated with an increased risk of developing gastric intestinal adenocarcinoma, the latter subtype is not. In this study, we evaluated the capability to classify common gastritis subtypes using convolutional neuronal networks on a small dataset of antrum and corpus biopsies. Methods: 1230 representative 500 × 500 µm images of 135 patients with type A, type B, and type C gastritis were extracted from scanned histological slides. Patients were allocated randomly into a training set (60%), a validation set (20%), and a test set (20%). One classifier for antrum and one classifier for corpus were trained and optimized. After optimization, the test set was analyzed using a joint result from both classifiers. Results: Overall accuracy in the test set was 84% and was particularly high for type B gastritis with a sensitivity of 100% and a specificity of 93%. Conclusions: Classification of gastritis subtypes is possible using convolutional neural networks on a small dataset of histopathological images of antrum and corpus biopsies. Deep learning strategies to support routine diagnostic pathology merit further evaluation.

Vitamin B12 Deficiency Among the Healthy Jordanian Adult Population: Diagnostic Levels, Symptomology and Risk Factors

BACKGROUND

Compared to the data available for developed countries, there is a marked scarcity of information on the levels and symptomology of vitamin B₁₂ deficiency in developing countries, particularly in the Middle Eastern region.

OBJECTIVE

To explore (a) the risk factors associated with a deficiency of vitamin B₁₂, and (b) the baseline (cut-off) serum level of vitamin B₁₂ for a clinically-symptomatic deficiency in the Jordanian adult population.

METHODS

A total of 485 subjects were included in this study. Blood samples were drawn for biochemical analysis and data regarding socio-demographics, general health, anthropometric measures, and past medical, surgical, and medication history were collected. To explore the cut-off point, we compared all parameters included in a standard complete blood count as well as the main symptoms reported to be associated with B₁₂ deficiency between groups of different B₁₂ cut-off values, consisting of those above and below 200, 175, 150 and 125 pg/ml.

RESULTS

Low dairy intake habits, age, recurrent headaches, heartburn, and peptic ulcer disease were found to be significantly associated with lower vitamin B₁₂ levels. Surprisingly, daily smoking was associated with significantly higher B₁₂ levels. The results revealed that none of the included potential indicators of B₁₂ deficiency could be considered an indicative feature of deficiency. There were no significant differences neither in the symptoms nor in the CBC parameters between any of the tested study groups.

CONCLUSION

Low dairy intake, older ages, recurrent headaches, heartburn, and peptic ulcer disease all could be considered as risk factors of having low vitamin B₁₂ levels within the Jordanians. Also, they tend to have lower levels of vitamin B₁₂ levels, in comparison to countries in the West, without necessarily having deficiency symptoms. The cut-off value to diagnose functional B₁₂ deficiency could be less than 125 pg/ml for the Jordanians. More local studies are needed to establish an accurate vitamin B₁₂ cut-off value for the population in Jordan.

Prevalence of Vitamin B12 Deficiency and its Associated Factors among Patients with Type 2 Diabetes Mellitus on Metformin from a District in Malaysia

Introduction

Vitamin B12 deficiency is more common among metformin-treated subjects although the prevalence is variable. Many factors have been associated with this. The aim of this study is to determine the prevalence of vitamin B12 deficiency and its associated factors among patients with type 2 diabetes mellitus (DM) who are on metformin.

Methodology

A total of 205 patients who fit eligibility criteria were included in the study. A questionnaire was completed, and blood was drawn to study vitamin B12 levels. Vitamin B12 deficiency was defined as serum B12 level of ≤300 pg/mL (221 pmol/L).

Results

The prevalence of vitamin B12 deficiency among metformin-treated patients with type 2 DM patients was 28.3% (n=58). The median vitamin B12 level was 419 (±257) pg/mL. The non-Malay population was at a higher risk for metformin-associated vitamin B12 deficiency [adjusted odds ratio (OR) 3.86, 95% CI: 1.836 to 8.104, p<0.001]. Duration of metformin use of more than five years showed increased risk for metformin-associated vitamin B12 deficiency (adjusted OR 2.06, 95% CI: 1.003 to 4.227, p=0.049).

Conclusion

Our study suggests that the prevalence of vitamin B12 deficiency among patients with type 2 diabetes mellitus on metformin in our population is substantial. This is more frequent among the non-Malay population and those who have been on metformin for more than five years.

Autoimmune gastritis

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B₁₂ (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H⁺/K⁺ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

Pernicious Anemia and Vitiligo in an HIV Patient: An Unfamiliar Case Presentation

Pernicious anemia (PA) is a rarely considered cause of anemia in HIV-infected population and is seldom on the list of differential diagnoses. However, PA can have serious consequences if misdiagnosed or left untreated. We present the case of a 38-year-old HIV-positive man who was diagnosed with PA, which was preceded by a one-year history of vitiligo. Our case is a reminder for clinicians to have a high index of suspicion for an autoimmune process as a potential cause of anemia in HIV-infected individuals.

Chronic Atrophic Gastritis with Negative Intrinsic Factor and Parietal Cell Antibody Presenting as a Severe Hemolytic Anemia

A 28-year-old Caucasian male with Hashimoto's disease and vitiligo presented with two weeks of dizziness on exertion following pharyngitis which was treated with prednisone 40 mg by mouth once a day for five days. Initial workup revealed anemia, elevated lactate dehydrogenase (LDH), and low haptoglobin. He underwent workup for causes of hemolytic anemia which was remarkable for a peripheral blood smear with hypersegmented neutrophils and low vitamin B12 levels concerning for pernicious anemia. Parietal cell and intrinsic factor antibodies were negative, and he then underwent an esophagogastroduodenoscopy with biopsy. The biopsy was negative for Helicobacter pylori, and the immunohistochemical stains were suggestive of chronic atrophic gastritis. He was started on vitamin B12 1,000 mcg intramuscular injections daily. His hemoglobin, LDH, and haptoglobin normalized. Given the absence of the parietal cell antibody and intrinsic factor antibody, this is a rare case of seronegative pernicious anemia.

Natural history of autoimmune atrophic gastritis: a prospective, single centre, long-term experience

BACKGROUND

Autoimmune atrophic gastritis (AAG) is an immune-mediated disorder characterised by destruction of gastric oxyntic mucosa AIM: To explore gastric histopathological evolution in a cohort of AAG patients over a prolonged follow-up METHODS: Single centre prospective study enrolling consecutive patients with histologically confirmed AAG between 2000 and 2018. All AAG patients undergoing endoscopic follow-up every 1-3 years were classified as having stages 1, 2 or 3 according to atrophy severity (mild, moderate and severe). AAG patients with either glandular or neuroendocrine dysplasia/neoplasia were classified as having stage 4. Disease stage progression, and changes in serum anti-parietal cell antibody (PCA), chromogranin A and gastrin-17 were assessed.

RESULTS

In total, 282 AAG patients (mean age 60.3 years; F:M ratio 2.4:1; median follow-up 3 years, interquartile range 1-7) were enrolled. All patients with stages 1 or 2 progressed to stage 2 or 3 over time with a steady trend (P = .243) and regression from a severe to a milder stage was never noticed. Disease progression of patients with stages 1 or 2 occurred within the first 3 years. PCA positivity rate did not change over time. Stage 3 patients had higher gastrin-17 levels compared to patients with stages 1 and 2 (median 606 vs 295 pg/mL; P < .001). In stage 3, the hazard ratio for the risk of developing stage 4 was 6.6 (95% CI 1.5-29; P = .001).

CONCLUSIONS

AAG is a steadily progressive disease, in which stages 1 and 2 always progress to stage 3. The risk of developing a complicated disease stage is greater in patients with more severe gastric lesions.

Cell Blood Count Alterations and Patterns of Anaemia in Autoimmune Atrophic Gastritis at Diagnosis: A Multicentre Study

BACKGROUND

Autoimmune atrophic gastritis (AAG) leads to iron and/or vitamin B12 malabsorption, with subsequent haematological alterations which could represent the sole clinical manifestation. We aimed to assess patterns of anaemia and micronutrient deficiencies in patients with AAG at the time of diagnosis.

METHODS

Observational, multicentre, cross-sectional study including consecutive adult patients diagnosed with AAG within the last ten years. Cell blood count, red cell distribution width, serum vitamin B12, and ferritin were collected. Multivariate analysis for predictive factors of anaemia was computed.

RESULTS

654 AAG patients (mean age 59.2 ± 13.8 years, female (F): male (M) ratio = 2.3:1) were included. Anaemia was present in 316 patients (48.3%; mean age 60.1 ± 15.8 years, F:M ratio = 2.3:1). Pernicious anaemia (132/316 cases, 41.7%) was more common in males (27.1% versus 12.4%; p = 0.001) and in older patients (63.0 ± 14.6 versus 58.9 ± 14.9 years; p = 0.014), while iron deficiency anaemia (112/316 cases, 35.4%) was more common in females (16.9% versus 10.0%; p = 0.039) and in younger patients (56.8 ± 16.6 versus 60.2 ± 14.6 years; p = 0.043). The prevalence of iron deficiency was equally distributed between anaemic and non-anaemic patients (p = 0.9). Anisocytosis (odds ratio: 10.65, 95% confidence interval: 6.13-18.50, p < 0.0001) was independently associated with anaemia.

CONCLUSIONS

Anaemia is a common manifestation in AAG patients, mostly due to micronutrient deficiencies. Scant haematologic alterations and micronutrient deficiencies may precede overt anaemia.

Determinants of diagnostic delay in autoimmune atrophic gastritis

BACKGROUND

Autoimmune atrophic gastritis (AAG) is characterised by a wide clinical spectrum that could delay its diagnosis.

AIMS

To quantify the diagnostic delay in patients suffering from AAG and to explore possible risk factors for longer diagnostic delay.

METHODS

Consecutive patients with AAG evaluated at our gastroenterological outpatient clinic between 2009 and 2018 were included. Diagnostic delay was estimated as the time lapse occurring between the appearance of the first likely symptoms, laboratory alterations, and other clues indicative of AAG and the final diagnosis. Patient-dependent and physician-dependent diagnostic delays were also assessed. Multivariable regression models were fitted.

RESULTS

291 patients with AAG (mean age at diagnosis 61 ± 15 years; F:M ratio = 2.3:1) were included. The median overall diagnostic delay was 14 months (interquartile range [IQR] 4-41). Factors associated with longer median overall diagnostic delay were female sex (17 months, IQR 5-48), having a previous misdiagnosis (36 months, IQR 17-125) and a history of infertility/miscarriages (33 months, IQR 8-120), whereas a higher level of education was associated with longer patient-dependent diagnostic delay (4 months, IQR 1-12). First evaluation by a gastroenterologist was associated with a median longer diagnostic delay (6 months, IQR 2-15) compared to an internist (3 months, IQR 3-31) and a haematologist (1 month, IQR 0-2). Age, socioeconomic or marital status did not affect the diagnostic delay.

CONCLUSIONS

AAG is burdened by substantial diagnostic delay, especially in female patients, and due to lack of awareness, particularly among gastroenterologists. Uncommon vitamin B12 deficiency-related manifestations are overlooked and may prolong the diagnostic delay.

Prevalence of Autoimmune Gastritis in Individuals Undergoing Medical Checkups in Japan

Objective Based on both endoscopic findings and serum auto-antibody levels, we determined the prevalence of autoimmune gastritis (AIG), which has not been previously reported, in individuals who underwent health checkup examinations in Japan. Methods At total of 6,739 subjects (4,288 males, 2,451 females; mean age 52.1 years) underwent an upper gastrointestinal endoscopic examination as part of an annual medical checkup. Those suspected to have AIG based on endoscopic evidence of proximal-predominant gastric mucosal atrophy were further examined for the presence of anti-parietal cells and anti-intrinsic factor antibodies, with a final diagnosis of AIG made in cases found to be positive for either or both of those factors. Results Of the 6,739 examined subjects, 46 were suspected to have AIG based on the endoscopic findings, of whom 33 were finally diagnosed with AIG, for an overall prevalence 0.49% (females 0.65%, males 0.40%). Seven with AIG also had thyroid disease, including Hashimoto's and Basedow disease, while none with AIG showed anemia in blood test findings. The prevalence of AIG was not different regardless of the H. pylori infection status (negative, positive, post-eradicated). Conclusion In individuals who underwent an upper gastrointestinal endoscopic examination as part of an annual checkup in Japan, the prevalence of AIG was 0.49%. We concluded that it is not uncommon for asymptomatic and healthy individuals to have AIG, and propose that additional studies are needed to clarify its prevalence as well as to establish the criteria used for diagnosis.