Anti-parietal cell antibodies - diagnostic significance

Protein Biomarkers of Gastric Preneoplasia and Cancer Lesions in Blood: A Comprehensive Review

Gastric cancer (GC) is a major cause of cancer-related mortality worldwide. It is often associated with a bad prognosis because of its asymptomatic phenotype until advanced stages, highlighting the need for its prevention and early detection. GC development is preceded by the emergence of gastric preneoplasia lesions (GPNLs), namely atrophic gastritis (AG), intestinal metaplasia (IM), and dysplasia (DYS). GC is currently diagnosed by endoscopy, which is invasive and costly and has limited effectiveness for the detection of GPNLs. Therefore, the discovery of non-invasive biomarkers in liquid biopsies, such as blood samples, in order to identify the presence of gastric preneoplasia and/or cancer lesions at asymptomatic stages is of paramount interest. This comprehensive review provides an overview of recently identified plasma/serum proteins and their diagnostic performance for the prediction of GPNLs and early cancer lesions. Autoantibodies appear to be promising biomarkers for AG, IM and early gastric cancer detection, along with inflammation and immunity-related proteins and antibodies against H. pylori virulence factors. There is a lack of specific protein biomarkers with which to detect DYS. Despite the need for further investigation and validation, some emerging candidates could pave the way for the development of reliable, non-invasive diagnostic tests for the detection and prevention of GC.

Improving the Diagnosis of Autoimmune Gastritis: From Parietal Cell Antibodies to H+/K+ ATPase Antibodies

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.

Vitamin B12 Deficiency Manifesting As Pancytopenia, Lymphadenopathy, and Fever: A Clinical Mimic of Hematologic Malignancies

Pancytopenia is a complex medical condition characterized by decreased levels of red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs). It can arise from impaired production, peripheral destruction, or a combination of both. The causes of pancytopenia range from reversible factors like infections and medication reactions to irreversible conditions. Vitamin B12 deficiency is a notable reversible cause that can take years to manifest in adults due to stored reserves. However, deficiencies caused by impaired absorption, especially due to the lack of intrinsic factors (IFs), can lead to rapid deterioration within two to five years. A healthy 39-year-old male with an athletic lifestyle presented with symptoms such as dizziness, nausea, vomiting, palpitations, and fainting over a few days. These symptoms were preceded by weeks of persistent body aches, headaches, weakness, daily fevers, chills, and night sweats. Vital signs were stable. The physical examination revealed conjunctival pallor and lymphadenopathy in the submandibular and superficial cervical regions. Initial blood tests showed normocytic anemia (Hgb 4.9, MCV 80), leukopenia (2.99), thrombocytopenia (142), and elevated liver enzymes (AST 199, ALT 96, and total bilirubin of 2.04). The peripheral smear showed tear-drop cells and hypochromic cells. The initial impression was hematologic malignancy, including but not limited to leukemia, lymphoma, or myelofibrosis given clinical findings such as B-symptoms like night sweats, neck lymphadenopathy, and subjective daily fever, along with pancytopenia. The patient received a bolus of normal saline and a transfusion of two units of packed RBCs. CT scans of the chest, abdomen, and pelvis showed no adenopathy or splenomegaly. Although initial clinical assessment pointed toward a potential hematologic malignancy, comprehensive testing, including SPEP, reticulocyte count/fraction, serum folate, and serum vitamin B12, revealed only severe vitamin B12 deficiency, with a level of less than 150, with the presence of IF antibodies. Treatment involved intensive in-patient vitamin B12 injections followed by a detailed outpatient regimen. The patient completed a daily dose of vitamin B12 injections for seven consecutive days, followed by weekly injections for the next four weeks. Subsequent laboratory results demonstrated an increase in WBC count to 8.39, Hgb level to 13.2, and PLT count of 249, indicating a continued positive response to the vitamin B12 replacement therapy. In summary, pancytopenia poses a diagnostic challenge that demands careful evaluation of patient data and comprehensive testing. Vitamin B12 deficiency, which encompasses pernicious anemia (PA), is among the reversible factors to consider. This aspect holds significance before opting for more invasive measures like a bone marrow biopsy. Nutritional deficiencies need to be considered first as differentials in pancytopenia, even in the absence of typical signs of vitamin B12 deficiency (like macrocytosis and hypersegmented neutrophils) and in the presence of compelling clinical indications pointing to a hematologic malignancy.

Oral vitamin B12 supplementation in pernicious anemia: a prospective cohort study

BACKGROUND

The absorption of vitamin B12 is hindered in pernicious anemia (PA) owing to intrinsic factor deficiency. Traditionally, intramuscular vitamin B12 injections were the standard treatment, bypassing the impaired absorption. Although there is potential for oral vitamin B12 supplementation through passive enteral absorption, it is not commonly prescribed in PA owing to limited studies assessing its efficacy.

OBJECTIVES

We aimed to assess the efficacy of oral vitamin B12 supplementation in PA.

METHODS

We enrolled participants diagnosed with incident vitamin B12 deficiency related to PA. The diagnosis of PA was based on the presence of classical immune gastritis and of anti-intrinsic factor and/or antiparietal cell antibodies. To evaluate the vitamin B12 status, we measured total plasma vitamin B12, plasma homocysteine, and plasma methylmalonic acid (pMMA) concentration and urinary methylmalonic acid-to-creatinine ratio. Participants were treated with oral cyanocobalamin at a dosage of 1000 μg/d throughout the study duration. Clinical and biological vitamin B12 deficiency related features were prospectively and systematically assessed over the 1-y study duration.

RESULTS

We included 26 patients with vitamin B12 deficiency revealing PA. Following 1 mo of oral vitamin B12 supplementation, 88.5% of patients were no longer deficient in vitamin B12, with significant improvement of plasma vitamin B12 [407 (297-485) compared with 148 (116-213) pmol/L; P < 0.0001], plasma homocysteine [13.5 (10.9-29.8) compared with 18.6 (13.7-46.8) μmol/L; P < 0.0001], and pMMA [0.24 (0.16-0.38) compared with 0.56 (0.28-1.09) pmol/L; P < 0.0001] concentrations than those at baseline. The enhancement of these biological parameters persisted throughout the 12-month follow-up, with no patients showing vitamin B12 deficiency by the end of the follow-up period. The median time to reverse initial vitamin B12 deficiency abnormalities ranged from 1 mo for hemolysis to 4 mo for mucosal symptoms.

CONCLUSIONS

Oral supplementation with 1000 μg/d of cyanocobalamin has been shown to improve vitamin B12 deficiency in PA.

Autoimmune Gastritis and Hypochlorhydria: Known Concepts from a New Perspective

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.

Autoimmune Atrophic Gastritis: A Clinical Review

Autoimmune atrophic gastritis (AAG) is a chronic condition characterized by the presence of atrophy in the oxyntic mucosa due to anti-parietal cell antibodies. This review provides a comprehensive and up-to-date overview of autoimmune atrophic gastritis, reporting recent evidence on epidemiology, pathogenesis, diagnosis, clinical presentation, risk of malignancies, and management. The prevalence of AAG has been estimated at between 0.3% and 2.7% in the general population. The diagnosis of AAG is based on a combination of the serologic profile and the histological examination of gastric biopsies. Patients with AAG are often asymptomatic but can also have dyspeptic or reflux symptoms. The atrophy of the oxyntic mucosa leads to iron and vitamin B12 malabsorption, which may result in anemia and neurological affections. Autoimmune atrophic gastritis is associated with an increased risk of type I neuroendocrine tumors (NETs) and gastric cancer, with an incidence rate of 2.8% and 0.5% per person/year, respectively. Management is directed to reinstate vitamins and iron and to prevent malignancies with endoscopic surveillance. In conclusion, atrophic autoimmune gastritis is an infrequent condition, often asymptomatic and misdiagnosed, that requires an early diagnosis for appropriate vitamin supplementation and endoscopic follow-up for the early diagnosis of NETs and gastric cancer.

Anti-parietal cell antibodies as a potential biomarker for interstitial lung disease associated with primary Sjögren's syndrome

BACKGROUND

ILD is a common manifestation in pSS and is associated with an increased risk of death. APCA are strongly expressed by hyperplastic alveolar epithelial cells in the fibrotic lung and are associated with an accelerated decline in lung function in IPF. In the present study, we aimed to evaluate the clinical utility of APCA in ILD patients with pSS.

METHODS

Clinical, laboratory, PFTs and imaging data from pSS patients were reviewed, and the ESSDAI was utilized to evaluate disease activity. HRCT semiquantitative scoring was conducted. We compared the clinical characteristics of pSS patients with and without ILD and carried out logistic regression analysis of risk factors for ILD in pSS.

RESULTS

A total of 74 patients with pSS and 40 HCs were included in the study. ILD was more commonly observed in the APCA-positive group than in the APCA-negative group. The quantitative levels of APCA were positively correlated with the imaging score. Multivariate analysis found that the long disease duration, elevated APCA and elevated KL-6 level were independent risk factors for ILD in pSS patients. The area under ROC curve for APCA was 0.6618, and the threshold concentration was 153.82ng/ml (sensitivity 45.24%, specificity 87.50%).

CONCLUSION

APCA level is an independent risk factor and might be a potential biomarker for ILD in patients with pSS.

FT4-to-FT3 ratio is a novel prognostic marker in subacute combined spinal cord degeneration patients

Objectives

The FT4-to-FT3 ratio (FFR) variations in patients with subacute combined spinal cord degeneration (SCSD) as a potentially useful prognostic indicator are still unknown. This study aimed to investigate the changes of FFR as a potentially valuable prognostic predictor in patients with SCSD.

Methods

This study included 144 consecutive SCSD patients who received standard diagnostic and therapeutic procedures between January 2015 and December 2021 and were admitted to the Department of Neurology at the First Affiliated Hospital of Bengbu Medical University. At the time of admission, we gathered data on all patients' demographics, daily routines, previous chronic conditions, medication histories, and other clinical details. For the purpose of measuring FFR, blood samples were specifically taken within 48 h of admission. The degree of neurological impairment of patients was assessed using the functional disability scale at the time of admission. At 6 months following discharge, the Modified Rankin Scale (mRS) was used to evaluate the clinical prognosis. To evaluate the relationship between the FFR and the risks of a poor outcome (mRS > 2), univariate and multivariate logistic regression analysis was utilized. The significance of the FT4/FT3 ratio in predicting the clinical outcomes in SCSD patients 6 months after discharge was assessed using the area under curve-receiver operating characteristic (AUC-ROC).

Results

About 90 patients (62.5%) of the 144 patients had poor outcomes, while 54 (37.5%) had favorable outcomes. Higher FFR at admission was independently linked to higher odds of a poor outcome, according to a logistic analysis. With an optimized cutoff value of >2.843, the FFR exhibited the maximum accuracy for predicting a poor outcome, according to the AUC‒ROC curve (AUC 0.731, P < 0.001; sensitivity, 77.8%; specificity, 83.3%). FFR was identified as an independent predictor of poor outcomes by multivariate logistic regression (OR, 2.244; 95% CI, 1.74-2.90; P < 0.001).

Conclusions

We discovered that in patients who had a bad result 6 months after discharge, the FFR had dramatically increased at the time of admission, providing a unique prognostic marker in patients with SCSD.

Th17 cytokines and factors modulating their activity in patients with pernicious anemia

The effects of specific cytokines produced by T cell subsets (such as Th1, Th2, and newly discovered Th17, Treg, Tfh, or Th22) are diverse, depending on interactions with other cytokines, distinct signaling pathways, phase of the disease, or etiological factor. The immunity equilibrium of the immune cells, such as the Th1/Th2, the Th17/Treg, and the Th17/Th1 balance is necessary for the maintenance of the immune homeostasis. If the balance of the T cells subsets is damaged, the autoimmune response becomes enhanced which leads to autoimmune diseases. Indeed, both the Th1/Th2 and the Th17/Treg dichotomies are involved in the pathomechanism of autoimmune diseases. The aim of the study was to determine the cytokines of Th17 lymphocytes as well as the factors modulating their activity in patients with pernicious anemia. The magnetic bead-based immunoassays used (Bio-Plex) allow simultaneous detection of multiple immune mediators from one serum sample. In our study, we showed that patients suffering from pernicious anemia develop the Th1/Th2 imbalance with a quantitative advantage of cytokines participating in Th1-related immune response, the Th17/Treg imbalance with a quantitative advantage of cytokines participating in Treg-related response, as well as the Th17/Th1 imbalance with a quantitative predominance of cytokines participating in Th1-related immune response. Our study results indicate that T lymphocytes and their specific cytokines play an role in the course of pernicious anemia. The observed changes may indicate the immune response to pernicious anemia or be an element of the pernicious anemia pathomechanism.

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.

Incidence and prevalence of gastric neuroendocrine tumors in patients with chronic atrophic autoimmune gastritis

BACKGROUND

The incidence of type I gastric neuroendocrine neoplasms (gNENs) has increased significantly over the past 50 years. Although autoimmune gastritis (AIG) increases the likelihood of developing gNENs, the exact incidence and prevalence of this association remain unclear.

AIM

To evaluate the incidence and prevalence of type I gNENs in a cohort of patients with a histological diagnosis of AIG.

METHODS

Patients with a histological diagnosis of AIG were enrolled between October 2020 and May 2022. Circulating levels of CgA and gastrin were assessed at enrollment. Included patients underwent regular endoscopic follow-up to detect gastric neoplastic lesions, enterochromaffin-like (ECL) cell hyperplasia, and the development of gNEN.

RESULTS

We included 176 patients [142 women (80.7%), median age 64 years, interquartile range (IQR) 53-71 years] diagnosed with AIG between January 1990 and June 2022. At enrollment. One hundred and sixteen patients (65.9%) had ECL hyperplasia, of whom, 29.5% had simple/linear, 30.7% had micronodular, and 5.7% had macronodular type. The median follow-up time was 5 (3-7.5) years. After 1032 person-years, 33 patients developed a total of 50 type I gNENs, with an incidence rate of 0.057 person-years, corresponding to an annual cumulative incidence of 5.7%. Circulating CgA levels did not significantly differ between AIG patients who developed gNENs and those who did not. Conversely, gastrin levels were significantly higher in AIG patients who developed gNENs [median 992 pg/mL IQR = 449-1500 vs 688 pg/mL IQR = 423-1200, P = 0.03]. Calculated gastrin sensitivity and specificity were 90.9% and 1.4%, respectively, with an overall diagnostic accuracy of 30% and a calculated area under the gastrin receiver operating characteristic curve (AUROC or AUC) of 0.53.

CONCLUSION

Type I gNENs are a significant complication in AIG. Gastrin's low diagnostic accuracy prevents it from serving as a marker for early diagnosis. Effective strategies for early detection and treatment are needed.

Atrophic Gastritis and Autoimmunity: Results from a Prospective, Multicenter Study

Despite a global decrease, gastric cancer (GC) incidence appears to be increasing recently in young, particularly female, patients. The causal mechanism for this "new" type of GC is unknown, but a role for autoimmunity is suggested. A cascade of gastric precancerous lesions, beginning with chronic atrophic gastritis (CAG), precedes GC. To test the possible existence of autoimmunity in patients with CAG, we aimed to analyze the prevalence of several autoantibodies in patients with CAG as compared to control patients. Sera of 355 patients included in our previous prospective, multicenter study were tested for 19 autoantibodies (anti-nuclear antibodies, ANA, anti-parietal cell antibody, APCA, anti-intrinsic factor antibody, AIFA, and 16 myositis-associated antibodies). The results were compared between CAG patients (n = 154), including autoimmune gastritis patients (AIG, n = 45), non-autoimmune gastritis patients (NAIG, n = 109), and control patients (n = 201). ANA positivity was significantly higher in AIG than in NAIG or control patients (46.7%, 29%, and 27%, respectively, p = 0.04). Female gender was positively associated with ANA positivity (OR 0.51 (0.31-0.81), p = 0.005), while age and H. pylori infection status were not. Myositis-associated antibodies were found in 8.9% of AIG, 5.5% of NAIG, and 4.4% of control patients, without significant differences among the groups (p = 0.8). Higher APCA and AIFA positivity was confirmed in AIG, and was not associated with H. pylori infection, age, or gender in the multivariate analysis. ANA antibodies are significantly more prevalent in AIG than in control patients, but the clinical significance of this finding remains to be established. H. pylori infection does not affect autoantibody seropositivity (ANA, APCA, AIFA). The positivity of myositis-associated antibodies is not increased in patients with CAG as compared to control patients. Overall, our results do not support an overrepresentation of common autoantibodies in patients with CAG.

Vitamin B12 levels in thyroid disorders: A systematic review and meta-analysis

Background and aims

Numerous studies have found an association between vitamin deficiency and thyroid disorders (TD). The presence of anti-parietal cell antibodies is indicative of reduced ability to absorb vitamin B12. Thus, this study reviewed the existing studies with the objective of assessing differences in the serum levels of vitamin B12 among patients with and without TD, the frequency of vitamin B12 deficiency in patients with TD, and the presence of anti-parietal cell antibodies in patients with TD.

Methods

A meta-analysis of random-effects model was conducted to calculate pooled frequencies, mean differences (MD), and their respective 95% confidence intervals (CI). We identified 64 studies that met our inclusion criteria (n = 28597).

Results

We found that patients with hypothyroidism had lower vitamin B12 levels than healthy participants (MD: -60.67 pg/mL; 95% CI: -107.31 to -14.03 pg/mL; p = 0.01). No significant differences in vitamin B12 levels were observed between healthy participants and patients with hyperthyroidism (p = 0.78), autoimmune thyroid disease (AITD) (p = 0.22), or subclinical hypothyroidism (SH) (p = 0.79). The frequencies of vitamin B12 deficiency among patients with hypothyroidism, hyperthyroidism, SH, and AITD were 27%, 6%, 27%, and 18%, respectively.

Conclusions

Patients with hypothyroidism had lower levels of vitamin B12 than healthy participants. No significant differences were observed between vitamin B12 levels and hyperthyroidism, AITD, or SH.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=324422, identifier (CRD42022324422).

Beyond skin white spots: Vitiligo and associated comorbidities

Vitiligo is a common depigmentation disorder of an unknown origin characterized by the selective loss of melanocytes, resulting in typical white macules and patches. However, vitiligo is now recognized as more than just a skin disease, what a dermatologist observes as a white spot of skin is just the "tip of the iceberg" of the condition. We attempt to clarify the classification of comorbidities associated with vitiligo from various reviews and reports, and describe their possible pathogenesis. In conclusion, the literature provides evidence of an association between vitiligo and ocular and auditory abnormalities, autoimmune disorders, other dermatological diseases, metabolic syndrome and related disorders, and psychological diseases. These associations highlight the importance of a multidisciplinary approach in managing vitiligo patients.

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.

[Clinical management of autoimmune gastritis]

Autoimmune gastritis (AIG) is a chronic immune-mediated inflammation of the gastric corpus/fundus mucosa leading to progressive atrophy of the oxyntic gastric glands (AOM) and their consecutive loss of function. Possible clinical consequences of AIG include iron deficiency anemia, pernicious anemia, gastric neuroendocrine tumors (gNET), and gastric adenocarcinoma. This article provides a review of interdisciplinary aspects of the diagnosis and treatment of AIG.

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.

Intrinsic factor autoantibodies by luminescent immuno-precipitation system in patients with corpus atrophic gastritis

Background

Corpus atrophic gastritis (CAG) may lead to intrinsic factor (IF) deficiency and vitamin B₁₂ malabsorption. Intrinsic factor autoantibodies (IFA) are considered markers of pernicious anemia, but their clinical utility in CAG has not been evaluated. This study aimed to assess IFA in CAG patients and controls using a luciferase immunoprecipitation system (LIPS).

Methods

Recombinant nanoluciferase-tagged IF secreted from transfected Expi293F cells was used as antigen in an IFA-LIPS assay. IFA IgG were measured in sera from subjects undergoing gastroscopy and biopsy (updated Sydney system) mainly for anemia (57%) or dyspepsia (34%). This cohort comprised 105 patients with histologically-proven-CAG (cases: median age 64 years, 68% females) and 110 subjects with suspected CAG that were histologically negative (controls: median age 67 years, 54% females). Cut-off values were selected by Q-Q-plot analysis (negative: <2.5 arbitrary units).

Results

IFA levels were higher in cases than in controls (Mann-Whitney:p < 10⁻⁵). The ROC-AUC was 0.67 (95%CI 0.60–0.73, p < 0.0001). The IFA LIPS sensitivity and specificity for CAG were 32% (95% CI 24–42) and 95% (95% CI 90–99). This diagnostic performance remained similar after stratification for the presence/absence of anemia, dyspepsia or vitamin B₁₂ deficiency. IFA levels were higher in females compared with males (p = 0.0127). In females aged <65 years, IFA-positives were more prevalent than in males (43.5% vs 6.6%, p = 0.011).

Conclusions

The IFA-LIPS assay discriminated between CAG patients and controls showing a good specificity (95%) at the cost of sensitivity (32%). IFA-positivity occurred independently from anemia and vitamin B₁₂ deficiency, but was more frequent in younger females. IFA testing should be considered in patients at high clinical suspicion of CAG.

•

A novel diagnostic autoantibody test for intrinsic factor autoantibodies using a LIPS in histologically-proven CAG patients and controls.

•

This assay discriminated between patients and controls with a good specificity and a relatively low sensitivity that reflects the likely low prevalence of intrinsic factor antibodies in CAG.

•

Positivity occurred independently from anemia and vitamin B₁₂ deficiency.

•

Intrinsic factor antibodies should be assessed in patients at high clinical suspicion of CAG.

How I investigate acquired megaloblastic anemia

In this review of megaloblastic anemia (MA), an overview of vitamin B₁₂ and folate body requirements, biochemical pathways, and laboratory testing strategies will be provided. However, the focus of this review is the classic and unique features of MA in blood and bone marrow. Acquired MA is a benign disorder for many, but can be detrimental for some. The clinical presentation can vary considerably, and the spectrum of symptoms and signs is diverse and quite broad. Prompt recognition and therapy are critical to prevent potential irreversible damage and clinical sequelae, especially in patients with vitamin B₁₂ deficiency. A delay in diagnosis of vitamin B₁₂ deficiency can result in significant neurologic sequelae that may not fully resolve with treatment, including in neonates and young infants. The blood and bone marrow features in MA can closely mimic thrombocytopenic purpura, myelodysplasia, and other myeloid neoplasms. Both pancytopenia and normal MCV at presentation are common in MA and raise unique challenges for the diagnostician. Partially treated MA is also a significant diagnostic "trap". MA is highly responsive to treatment, and patients tend to improve rapidly upon treatment initiation. However, the broad range of clinical and hematologic features makes the rapid, successful diagnosis of MA a unique challenge for the hematopathologist. Even in the era of state-of-the-art laboratory testing, a high suspicion is required.

Hashimoto Thyroiditis, Anti-Parietal Cell Antibodies: Associations With Autoimmune Diseases and Malignancies

BACKGROUND

Hashimoto thyroiditis (HT) is an autoimmune disease which may result in extensive damage of the thyroid gland. Chronic atrophic gastritis (CAG), is the most frequent HT-associated disorder, with anti-parietal cell autoantibodies (APCA) being a screening test for autoimmune CAG. The aim of this study was to investigate, in a cohort of HT patients: a) the prevalence of APCA in an attempt to define their clinical phenotype and b) any possible associations of APCA with other autoimmune diseases and malignancies.

METHODS

This is a single-center, case-control study, conducted at a University Hospital. The study included patients with HT diagnosed between November 2017 and November 2020. Excluded were patients <18 years old, with sonographic features of HT but negative thyroid peroxidase (TPOAbs) or thyroglobulin autoantibodies (TgAbs), Graves' disease, Down or Turner's syndrome.

RESULTS

A total of 840 patients with HT were included in the study, from whom 180 (21.4%) had positive APCA. A total of 79 patients (9.4%) had one or more organ-specific autoimmune diseases and 61 (7.3%) had a systemic autoimmune disease. Autoimmune diseases were more frequent in female than in male patients (17.9% versus 10.9%, p = 0.05). APCA-positive patients were older than APCA-negative (54.1 ± 13.5 versus 49.0 ± 14.6, p <0.001) and had more often positive TPOAbs (93.3% versus 83.9%, p=0.001). Gastric neoplasms were documented only in APCA-positive patients (p <0.001). A higher frequency of organ-specific autoimmune diseases was observed in the APCA-positive group (14.4% versus 8%, p = 0.024). In the subgroup of patients with additional autoimmune diseases (n = 140), younger age and positive APCA were independently associated with the presence of organ-specific autoimmunity (OR 0.954, 95% CI 0.927-0.982 and OR 3.100, 95% CI 1.256-7.652, respectively). Papillary thyroid cancer (PTC) occurred in 3.5% of patients (26/29 women). Positive family history for thyroid autoimmunity and negative TPOAbs were the only independent risk factors for PTC among women (OR 3.228, 95% CI 1.173-8.887 and 0.315, 95% 0.113-0.881, respectively).

CONCLUSION

This study reveals for the first time an association of APCA with organ-specific autoimmunity in HT patients. APCA together with patient age were independently associated with the presence of organ-specific autoimmunity. Finally, this study showed an association between APCA and gastric neoplasms in these patients.

Clinical Recommendations of Russian Gastroenterological Association and RENDO Endoscopic Society on Diagnosis and Treatment of Gastritis and Duodenitis

Aim.The clinical guidelines are intended to supplement specialty decision-making for improved aid quality in patients with gastritis and duodenitis though acknowledging the latest clinical evidence and principles of evidencebased medicine.Key points.Gastritis is an inflammatory disease of stomach mucosa, with a separate definition of acute and chronic gastritis. Chronic gastritis is a cohort of chronic diseases uniting a typical morphology of persistent inflammatory infiltration, impaired cellular renewal with emergent intestinal metaplasia, atrophy and epithelial dysplasia of gastric mucosa. Oesophagogastroduodenoscopy (OGDS) or high-resolution OGDS with magnified or non-magnified virtual chromoendoscopy, including targeted biopsy for atrophy and intestinal metaplasia grading and neoplasia detection, are recommended to verify gastritis and duodenitis, precancer states and/or gastric mucosal changes. All chronic gastritis patients positive for H. рylori should undergo eradication therapy as aetiological and subsidiary for gastric cancer prevention. Chronic gastritis patients with symptoms of dyspepsia (epigastric pain, burning and congestion, early satiety), also combined with functional dyspepsia, are recommended proton pump inhibitors, prokinetics, rebamipide and bismuth tripotassium dicitrate in symptomatic treatment. With focal restricted intestinal metaplasia, follow-up is not required in most cases, mainly when advanced atrophic gastritis is ruled out in high-quality endoscopy with biopsy. However, a familial history of gastric cancer, incomplete intestinal metaplasia and persistent H. pylori infection render endoscopy monitoring with chromoendoscopy and targeted biopsy desirable once in three years. Patients with advanced atrophic gastritis should have high-quality endoscopy every 3 years, and once in 1–2 years if complicated with a familial history of gastric cancer.Conclusion.The recommendations condense current knowledge on the aetiology and pathogenesis of gastritis and duodenitis, as well as laboratory and instrumental diagnostic techniques, main approaches to aetiological H. pylori eradication and treatment of dyspeptic states.

Association of Antiparietal Cell and Anti-Intrinsic Factor Antibodies With Risk of Gastric Cancer

Question

Is there an association between autoantibodies to gastric mucosa and gastric cancer (GC)?

Findings

In this cohort study of 529 female matched pairs from the Finnish Maternity Cohort and 457 male matched pairs from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, prediagnostic seropositivity to antiparietal cell antibodies was associated with the elevated risk of GC among young women born in 1938 through 1989 during a median of 17 years follow-up but not among older men born in 1916 through 1939 during a median of 11 years follow-up. The magnitude of association was stronger in Helicobacter pylori–seronegative women and most pronounced for tumors in the corpus.

Meaning

With the waning prevalence of H pylori, autoimmune-driven GC may explain the recent rise of GC incidence among the younger female population.

Importance

Autoimmune gastritis is an alternative cause of gastric carcinogenesis. This cause may be gaining importance with declining prevalence of chronic Helicobacter pylori infection.

Objective

To determine the association of prediagnostic autoantibodies to gastric mucosa with gastric cancer (GC) risk.

Design, Setting, and Participants

This cohort study used nested GC case-control analyses within separate Finnish cohorts of women of reproductive age (Finnish Maternity Cohort [FMC]; born 1938-1989) and older men (Alpha-Tocopherol, Beta-Carotene Cancer Prevention [ATBC] Study; born 1916-1939). There were 529 and 457 matched pairs from the FMC and ATBC Study, respectively, with mean participant ages of 30.5 and 57.5 years and medians of 17 and 11 years from baseline to cancer diagnosis. Data analyses were performed between August 2019 and November 2020.

Exposures

Antiparietal cell antibodies (APCAs), anti-intrinsic factor antibodies, and anti–H pylori antibodies were measured in baseline serum using immunoassays.

Main Outcomes and Measures

Autoantibody associations were estimated by odds ratios (ORs) and 95% CIs.

Results

Of the 529 control participants in the FMC and 457 control participants in the ATBC Study, 53 (10%) women and 35 (7.7%) men were APCA seropositive, respectively, whereas 146 (28%) women and 329 (72%) men were H pylori seropositive. In the FMC, APCA seropositivity was statistically significantly associated with GC risk among H pylori-seronegative women (OR, 5.52; 95% CI, 3.16-9.64) but not H pylori-seropositive women (OR, 1.29; 95% CI, 0.64-2.60; P for interaction = .002). The APCA association with H pylori seronegativity was strongest for tumors in the fundus and corpus (OR, 24.84; 95% CI, 8.49-72.72). In the ATBC Study, APCA seropositivity was not associated with GC among either H pylori–seronegative men (OR, 0.99; 95% CI, 0.32-3.04) or H pylori–seropositive men (OR, 1.06; 95% CI, 0.60-1.88). In both cohorts, anti-intrinsic factor antibody seroprevalence was less than 2% among cases as well as controls and not statistically associated with GC risk.

Conclusions and Relevance

Results of this cohort study demonstrate that autoantibody positivity may reflect subclinical autoimmune gastritis in younger women. The findings among young females and corpus subsite align with increasing cancer incidence trends for these groups. Stronger autoimmune associations in H pylori-seronegative individuals support a model of autoimmune gastritis replacing H pylori as the driving factor.

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.

Mucocutaneous Manifestations in Autoimmune Gastritis: A Prospective Case-Control Study

INTRODUCTION

Autoimmune gastritis (AIG) is associated with nutritional deficiencies, autoimmune diseases, and gastric malignancies. The aims of the study were to test the hypothesis that mucocutaneous (MC) manifestations occur more often in patients with vs without AIG and to delineate patterns of MC manifestations in AIG.

METHODS

A single-center, prospective 2:1 case-control study was conducted. Cases were patients with the diagnosis of AIG based on consistent serologic and histologic findings. Controls had a normal gastric biopsy. MC manifestations were independently evaluated by 3 experienced dermatologists. We conducted a multivariable logistic regression model adjusted for age, sex, Helicobacter pylori, tobacco use, and alcohol consumption to estimate the association between AIG (vs no AIG) and MC manifestations (adjusted odds ratio; 95% confidence interval).

RESULTS

We prospectively enrolled 60 cases and 30 controls (mean age 53.5 ± 15.8 vs 53.4 ± 14.5 years; 75% vs 73.3% women). The pooled prevalence of MC immune-mediated diseases was higher in patients with vs without AIG (66.7% vs 23.3%; adjusted odds ratio 12.01 [95% confidence interval: 3.51-41.13]). In patients with AIG, seropositive vs seronegative anti-intrinsic factor antibodies more often had concomitant immunological diseases with MC manifestations (100% vs 58.5%; P = 0.016). The most common MC immune-mediated diseases in AIG were Sjögren syndrome (n = 5, 8.3%), alopecia areata (n = 5, 8.3%), and vitiligo (n = 4, 6.7%). Nutritional deficiency-related MC findings, mainly xerosis, lingual, and nail disorders, were also more common in AIG.

DISCUSSION

This is the first comparative study specifically designed to evaluate MC manifestations in AIG. We demonstrated that AIG is more frequently associated with both immune- and nutritional deficiency-related MC manifestations, which might have both diagnostic and therapeutic clinical implications.

Chronic Autoimmune Gastritis: Modern Diagnostic Principles

This article summarizes and systematizes the available data from the literature on chronic autoimmune gastritis (CAG) in order to increase the awareness of specialists about the modern possibilities for diagnosing the disease, including its early stages. The clinical manifestation of the disease includes possible variants such as gastrointestinal, hematological (first of all, the formation of iron deficiency and B12-deficiency anemia), and neurological variants. Patients with chronic autoimmune gastritis are characterized by comorbidity with other autoimmune diseases. In this paper, data on the most informative serological markers for the diagnosis of CAG, as well as laboratory tests to detect micronutrient deficiencies, information on the characteristic changes in the gastric mucosa, and the prognosis of the disease, are presented. The diagnosis of CAG should be based on a multidisciplinary approach that combines a thorough analysis of a patient's complaints with a mandatory assessment of nutritional status, as well as the results of serological, endoscopic, and histological research methods.

Validation of diagnostic strategies of autoimmune atrophic gastritis: A case report

BACKGROUND

Autoimmune atrophic gastritis (AAG) is a type of chronic gastritis that mainly affects the gastric corpus. Due to the lack of standard diagnostic criteria and overlaps with the courses of Helicobacter pylori-related atrophic gastritis, reports on the diagnostic strategy of AAG at an early stage are limited.

CASE SUMMARY

A 71-year-old woman with severe anemia was diagnosed with AAG. Endoscopic views and pathological findings showed the coexistence of normal mucosa in the gastric antrum and atrophic mucosa in the gastric fundus. Serological tests showed that anti-parietal cell antibodies and anti-intrinsic factor antibodies were both positive. Immunohistochemical results, which showed negative H⁺-K⁺ ATPase antibody staining and positive chromogranin A (CgA) staining, confirmed the mechanism of this disease. After vitamin B12 and folic acid supplementation, the patient recovered well.

CONCLUSION

Successful diagnosis of AAG includes serological tests, endoscopic characteristics, and immunohistochemistry for H⁺-K⁺ ATPase and CgA antibodies.

Autoimmune gastritis, with or without pernicious anemia: epidemiology, risk factors, and clinical management

Autoimmune gastritis (AIG) is a chronic immune-mediated, inflammatory condition that involves the destruction of the gastric oxyntic mucosa through the autoimmune-mediated loss of parietal cells, with replacement by atrophic and metaplastic tissue. Diagnosing AIG is important, given the need for ongoing clinical management and vigilance with respect to downstream complications, the most serious of which is gastric adenocarcinoma. Other clinical consequences include gastric neuroendocrine tumors, consequences related to decreased gastric acid and decreased intrinsic factor due to parietal cell destruction and antibodies against intrinsic factor (e.g. micronutrient deficiencies), as well as concomitant autoimmune disorders. Considering the prevalence of AIG and the potential for severe clinical outcomes, it is important to engage in efforts to reduce practice pattern variability related to diagnosis and management. Accordingly, herein, we review of the epidemiology, pathogenesis, clinical presentation of AIG, including both gastric and extragastric manifestations, and provide an overview of clinical management.

Proteomics signature of autoimmune atrophic gastritis: towards a link with gastric cancer

BACKGROUND

Autoimmune atrophic gastritis (AAG) is a chronic disease that can progress to gastric cancer (GC). To better understand AAG pathology, this proteomics study investigated gastric proteins whose expression levels are altered in this disease and also in GC.

METHODS

Using two-dimensional difference gel electrophoresis (2D-DIGE), we compared protein maps of gastric corpus biopsies from AAG patients and controls. Differentially abundant spots (|fold change|≥ 1.5, P < 0.01) were selected and identified by LC-MS/MS. The spots were further assessed in gastric antrum biopsies from AAG patients (without and with Helicobacter pylori infection) and from GC patients and unaffected first-degree relatives of GC patients.

RESULTS

2D-DIGE identified 67 differentially abundant spots, with 28 more and 39 less abundant in AAG-corpus than controls. LC-MS/MS identified these as 53 distinct proteins. The most significant (adjusted P < 0.01) biological process associated with the less abundant proteins was "tricarboxylic acid cycle". Of the 67 spots, 57 were similarly differentially abundant in AAG-antrum biopsies irrespective of H. pylori infection status. The differential abundance was also observed in GC biopsies for 14 of 28 more abundant and 35 of 39 less abundant spots, and in normal gastric biopsies of relatives of GC patients for 6 and 25 spots, respectively. Immunoblotting confirmed the different expression levels of two more abundant proteins (PDIA3, GSTP gene products) and four less abundant proteins (ATP5F1A, PGA3, SDHB, PGC).

CONCLUSION

This study identified a proteomics signature of AAG. Many differential proteins were shared by GC and may be involved in the progression of AAG to GC.

Autoimmune Gastritis and Gastric Microbiota

Autoimmune atrophic gastritis is an organ-specific immune-mediated condition characterized by atrophy of the oxyntic mucosa. Autoimmune atrophic gastritis (AIG) is characterized by a progressive loss of acid-secreting parietal cells leading to hypo-achlorhydria. Due to this peculiar intra-gastric environment, gastric microbiota composition in individuals with autoimmune atrophic gastritis was first supposed and then recently reported to be different from subjects with a normal acidic healthy stomach. Recent data confirm the prominent role of Helicobacter pylori as the main bacterium responsible for gastric disease and long-term complications. However, other bacteria than Helicobacter pylori, for example, Streptococci, were found in subjects who developed gastric cancer and in subjects at risk of this fearful complication, as well as those with autoimmune gastritis. Gastric microbiota composition is challenging to study due to the acidic gastric environment, the difficulty of obtaining representative samples of the entire gastric microbiota, and the possible contamination by oral or throat microorganisms, which can potentially lead to the distortion of the original gastric microbial composition, but innovative molecular approaches based on the analysis of the hyper-variable region of the 16S rRNA gene have been developed, permitting us to obtain an overall microbial composition view of the RNA gene that is present only in prokaryotic cells.

Seronegative autoimmune atrophic gastritis is more common in elderly patients

BACKGROUND

Autoimmune atrophic gastritis (AAG) diagnosis is based on specific histological findings and anti-parietal cell antibodies (PCA) considered the serological hallmark of AAG, although a subgroup of AAG patients may be seronegative.

OBJECTIVES

To assess the occurrence and clinical features of seronegative compared to seropositive AAG.

METHODS

This is a cross-sectional study including 516 consecutive adult patients (age 59.6 ± 12.8 years, F:M = 2.2:1) with histologically proven AAG diagnosed in two Italian academic referral centers over the last 10 years. PCA were detected at AAG diagnosis. Variables related to the dependent variable of interest (i.e.PCA-negativity) were assessed by univariate/logistic regression analysis.

RESULTS

109/516 AAG patients were seronegative. The mean age of seronegative AAG patients was significantly higher compared to PCA-positive (65.9 ± 14.1vs57.9 ± 15.1 years; p<0.0001). The proportion of patients aged 70-79 and ≥80 years were, respectively, lower for PCA-positivity (5.1vs12.8%;21.3vs38.5%;p<0.005). Seronegativity was associated with age ≥50 years (OR2.4;95%CI 1.1-5.2), while for other variables (gender, comorbidities, anemia, atrophy severity) no association was found. In a sub-cohort of 101 AAG patients, PCA levels detected by ELISA were inversely correlated with age at AAG diagnosis (rho=-0.250;p = 0.0118).

CONCLUSION

Roughly 20% of patients are seronegative at the time of AAG histological diagnosis and this is more common in elderly individuals.

Banxia Xiexin Decoction in the treatment of chronic atrophic gastritis: A protocol for systematic review and meta-analysis

BACKGROUND

Chronic atrophic gastritis (CAG) is a common digestive disease. Without active treatment, it may induce gastric cancer. Western medicine has a certain effect on chronic atrophic gastritis, but there are many adverse reactions after long-term medication, and the disease is prone to relapse after treatment, which will affect the health and life of patients. Traditional Chinese medicine has obvious advantages in the treatment of chronic stomach diseases with reliable effect. A number of clinical data have also confirmed that Banxia Xiexin decoction has significant effect in the treatment of chronic atrophic gastritis, but there is no evidence of evidence-based medicine. Therefore, this study aims to explore the clinical efficacy and safety of Banxia Xiexin decoction in the treatment of chronic atrophic gastritis by means of systematic evaluation.

METHOD

Databases including PubMed, The Cochrance Library, Embase, Web of Science, CNKI, VIP, and Wanfang were searched by computer. Besides, Baidu Scholar and Google Scholar were manually searched, and all randomized controlled trials of Banxia xiexin decoction for the treatment of chronic atrophic gastritis were collected. The retrieval time was from the establishment of the database to July 31, 2020. After 2 reviewers independently screened the literature, extracted the data and evaluated the bias risk of the included study, RevMan5.3 software (developed by the UK's International Cochrane Collaboration) was used to analyze the data.

RESULTS

In this study, the effectiveness and safety of Banxia Xiexin decoction for the treatment of chronic atrophic gastritis were evaluated by the clinical efficiency, traditional Chinese medicine syndrome score (traditional Chinese medicine syndrome score), quality of life score, gastrin level, epidermal growth factor, eradication rate of helicobacter pylori and incidence of adverse reactions.

CONCLUSION

This study will provide reliable evidence for the clinical application of Banxia Xiexin decoction in the treatment of chronic atrophic gastritis.

ETHICS AND DISSEMINATION

The private information from individuals will not be published. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/7K6QW.

Autoantibodies Toward ATP4A and ATP4B Subunits of Gastric Proton Pump H+,K+-ATPase Are Reliable Serological Pre-endoscopic Markers of Corpus Atrophic Gastritis

INTRODUCTION

Noninvasive assessment of corpus atrophic gastritis (CAG), a condition at increased risk of gastric cancer, is based on the measurement of pepsinogens, gastrin, and Helicobacter pylori antibodies. Parietal cell autoantibodies (PCAs) against the gastric proton pump (ATP4) are potential serological biomarkers of CAG. The purpose of this study was to compare the diagnostic performance of PCA and pepsinogen I tests in patients with clinical suspicion of CAG with the histopathological evaluation of gastric biopsies as reference standard.

METHODS

A prospective case-finding study was performed on 218 naive adult patients (131 women, median age 65 years) who underwent gastric biopsies to confirm/exclude CAG. Patients with histopathological CAG were defined as cases, conversely as controls. Autoantibodies against the individual alpha (ATP4A) and beta (ATP4B) subunits of ATP4 were measured by luciferase immunoprecipitation, and global PCA and pepsinogen I by enzyme-linked immunosorbent assay.

RESULTS

Histopathology classified 107 subjects (49%) as cases (CAG+, autoimmune 81.2%, and multifocal extensive 18.8%) and 111 subjects (51%) as controls (CAG-). In cases, ATP4A, ATP4B, and PCA titers were increased compared with controls, whereas pepsinogen I was reduced (P < 0.0001 for all). ATP4B, ATP4A, and pepsinogen I tests showed sensitivities of 77%, 75%, and 73% and specificities of 88%, 88%, and 80%, respectively. The receiver operating characteristic (ROC) area under the ROC curve (AUC) of these serological biomarkers confirmed their ability to discriminate cases from controls (ATP4B = 0.838, ATP4A = 0.826, pepsinogen I = 0.775, and PCA = 0.805), whereas the partial ROC-pAUC90 analysis showed that the ATP4B test had the best diagnostic performance (P = 0.008 vs ATP4; P = 0.0002 vs pepsinogen I). The presence of autoimmune or extensive gastritis was not significantly different between ATP4B positive or negative cases (P = 0.217).

DISCUSSION

PCAs are promising serological biomarkers for the identification of CAG in high-risk individuals, particularly in an autoimmune pattern but also in an extensive-multifocal atrophy pattern.

Prevalence of latent and overt polyautoimmunity in autoimmune thyroid disease: A systematic review and meta-analysis

BACKGROUND

Thyroid autoimmunity is the most frequent condition involved in polyautoimmunity (PolyA). However, the frequency of latent and overt PolyA in patients with autoimmune thyroid disease (AITD) as the index condition is unknown. Therefore, the purpose of this study was to determine the prevalence of these types of PolyA in patients with AITD as the index condition.

METHODS

This study adhered to the relevant sections of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. Searches through MEDLINE, Embase and LILACS were done to find articles in Spanish and English. Relevant vocabulary terms and key terms related to AITD and other autoimmune diseases were used. Two investigators independently screened the eligible studies, extracted data and assessed the quality and risk of bias. Fixed and random effect models were used accordingly. Cluster analysis was used to determine similarities among diseases in the articles included (based on Jaccard index).

RESULTS

A total of 56 articles fulfilled the inclusion criteria. Of these, 25 were case-controls, 17 were cohorts, and 14 were cross-sectional studies. These studies included a total of 47 509 patients. Female was the predominant gender and included 38 950 patients (81.23%, 95% CI: 80.85-81.60). Graves' disease (GD) was the most common type of thyroid autoimmunity (69.16%, 95% CI: 68.23-70.07). Globally, overt PolyA was found in 13.46% of the patients with AITD. This type of PolyA was represented mainly by type 1 diabetes and autoimmune gastritis. Latent PolyA was presented in 17.45% of the patients, and anti-proinsulin, anti-parietal cells and dsDNA antibodies were the most common. HT had the highest frequency of overt PolyA in Europe (15.60%, 95% CI: 14.72-16.53), whereas latent PolyA was most common in patients with GD in Asia (21.03%, 95% CI: 17.76-24.71). Overt and latent PolyA were associated with gastrointestinal and endocrinological ADs in most of cases and clustered with rheumatological, dermatological and neurological ADs.

CONCLUSIONS

Latent and overt PolyA are common in patients with AITD. These results provide insightful information for early diagnosis and management of concurrent ADs in patients with AITD. Aggregation of ADs in different clusters may help to define different phenotypes associated with thyroid autoimmunity that are critically relevant in clinical settings.

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.

Comparison of different immunoassays for the detection of antibodies against Intrinsic Factor and Parietal Cells

OBJECTIVES

In the diagnostic work up of autoimmune gastritis several immunological methods are available for the detection of antibodies against Intrinsic Factor (IF) and Parietal Cells (PC). However, there are no recent reports directly comparing all the available assays and methods. The objective of this study was to compare the performance of several commercially available anti-IF and anti-PC antibody assays from different manufacturers in a multi-center multi-cohort setting.

METHODS

Sera were used from 5 different cohorts consisting of samples from 25 healthy elderly, 20 HCV or HIV positive patients and 150 patients positive for anti-IF or anti-PC antibodies or in whom these antibodies were requested. These cohorts were tested for anti-IF antibodies with 6 different assays (IIF, ELISA, DIA and EliA) and for anti-PC antibodies with 7 different assays (IIF, ELISA, DIA and EliA). Performance was evaluated by calculating the concordance and relative sensitivity and specificity.

RESULTS

Good concordance was found between the assays for both antibody specificities, ranging from 81 to 100% and 91-100% for anti-IF and anti-PC antibodies, respectively. Highest relative sensitivity was found with the (automated) ELISA based methods. However, all assays had a relative sensitivity between 85 and 100% for anti-IF antibodies and between 95 and 100% for anti-PC antibodies. The relative specificity ranged between 76 and 100% for anti-IF antibodies and between 96 and 100% for anti-PC antibodies.

CONCLUSIONS

We conclude that most assays perform well and are concordant to each other, despite the methodological differences and the different sources of antigen used. However, the method used affects the sensitivity and specificity. The (automated) ELISA based assays have the highest relative sensitivity and relative specificity. Care should be taken in the interpretation of positive results by IIF and negative results by the Blue Diver when testing for anti-IF antibodies.

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.

Microangiopathic haemolytic anaemia and thrombocytopenia due to combined vitamin B12 and folate deficiency masquerading as thrombotic thrombocytopenic purpura

Vitamin B12 deficiency and folate deficiency are common causes of macrocytic anaemia and both are important for many cellular processes. These deficiencies could be due to inadequate dietary intake, impaired absorption or drug ingestion. We present a case of a 47-year-old male with a history of diffuse large B-cell lymphoma (DLBCL) who was admitted for fatigue, persistent frontal headache and left upper-quadrant abdominal pain. Further investigation showed that he had pancytopenia with microangiopathic haemolytic anaemia (MAHA) and intracranial bleeding (ICB). Serum vitamin B12 and folate were later found to be low and a diagnosis of combined vitamin B12 and folate deficiency mimicking thrombotic thrombocytopenic purpura (TTP) was made. The patient responded well to vitamin B12 and folate replacement.

Current Perspectives in Atrophic Gastritis

PURPOSE OF THE REVIEW

Atrophic gastritis is a complex syndrome with gastric atrophy as a common trait. Helicobacter pylori infection and autoimmunity are the two main contexts in which it develops. It is slightly symptomatic, affects various aspects of general health, and remains a predisposing factor for gastric cancer. This review will update current knowledge and progress on atrophic gastritis.

RECENT FINDINGS

Atrophic gastritis affects mostly adults with persistent dyspepsia, deficient anemia, autoimmunity disease, long-term proton pump inhibitor use, and a family history of gastric cancer. Gastric biopsies, expressed as Sydney system grade and OLGA/OLGIM classifications, represent the gold standard for diagnosis and cancer risk stage, respectively. Recently, electronic chromoendoscopy has allowed "targeted biopsies" of intestinal metaplasia. The associated hypochlorhydria affects the gastric microbiota composition suggesting that non-Helicobacter pylori microbiota may participate in the development of gastric cancer. Physicians should be aware of multifaceted clinical presentation of atrophic gastritis. It should be endoscopically monitored by targeted gastric biopsies. Autoimmune and Helicobacter pylori-induced atrophic gastritis are associated with different gastric microbial profiles playing different roles in gastric tumorigenesis.

Type 1 diabetes, thyroid, gastric and adrenal humoral autoantibodies are present altogether in almost one third of adult celiac patients at diagnosis, with a higher frequency than children and adolescent celiac patients

Background: No data are available on the frequency of organ-specific humoral autoimmunity at diagnosis of adult celiac disease (CD).Aim: To evaluate the humoral immunoreactivities specific of type 1 diabetes (T1D), thyroid (THD), atrophic-gastritis (AG) and Addison's (AD) diseases in 92 adult CD patients at diagnosis and 237 adult healthy subjects (CTRL).Methods: T1D, THD and AD specific autoantibodies were analyzed by radioimmunoprecipitation assays. AG autoantibodies were detected by enzyme-linked immunosorbent assay.Results: Of 92 CD patients, 31.5% were positive for at least one of the organ-specific autoantibodies investigated (p < .0001 vs CTRL). Thyroid, diabetes, gastric and adrenal-autoantibodies, that increase with age at diagnosis, were detected in 12.0%, 10.9%, 10.9%, 2.2% of CD patients, respectively. Gastric- and diabetes- rather than thyroid- and adrenal-autoimmunity seem to be specifically related to presence of CD.Conclusions: One third of adult CD patients at diagnosis is target of at least one organ-specific autoantibody. A systematic organ-specific autoantibody screening in these patients might be of value to promptly identify, prevent or treat the relative diseases.

Analysis of clinical characteristics of 2243 with positive anti-gastric parietal cell antibody

Background

To facilitate the early detection of chronic diseases, we analyzed the clinical characteristics of anti‐gastric parietal cell antibody (PCA)‐positive population, revealed the early characteristics of the population.

Methods

According to the retrospective analysis, current situation investigation and comparative analysis of the clinical characteristics and medical history of the subjects, the comparison between the groups was performed.

Result

(a) The positive rate of PCA detection in department of gastroenterology in our hospital was 35.80%. Among the individuals who underwent PCA, esophagogastroduodenoscopy (EGD) and pathological examination at the same time, 33.59% of the patients with PCA positive were diagnosed as atrophic gastritis by gastroscopy, which was much higher than 9.09% of the patients with PCA negative. (b) The incidence of gastroesophageal reflux, hypertension, ischemic heart disease (IHD) and cerebral ischemia in PCA‐positive population were 65.45%, 81.63%, 15.43%, and 31.61%, respectively, which were significantly higher than those in the control group. (c) The incidence rates of decreased red blood cells (RBC) and increased homocysteine (HCY) in laboratory‐related tests were 38.30% and 69.15%, respectively, which were much higher than those in control group.

Conclusion

PCA has predictive value for a variety of chronic diseases and timely detection is of great significance.

A current clinical overview of atrophic gastritis

Introduction: Atrophic gastritis (AG) is a complex syndrome which arises as a consequence of H. pylori infection or in the context of gastric autoimmunity. It often deserves a benign course but may lead to potentially life-threatening complications: cancer and anemia. This review aims to address traditional and innovative knowledge on this often under-diagnosed disorder.Areas covered: This review covers clinical presentation, risk factors, diagnosis, and management of AG and provides an updated resource for clinicians to get insight into this challenging disorder. Updated literature was searched in PubMed. Manual search from reference lists of publications was performed.Expert opinion: A case-finding strategy may be beneficial in individuals with anemia, dyspepsia, autoimmune thyropaties and type 1 diabetes, and family history of gastric cancer. AG is linked to gastric cancer risk and endoscopic surveillance is indicated according to topography of gastric atrophy and risk factors. The direction for future research in AG is summarized.

Autoimmune Gastritis in Pediatrics: A Review of 3 Cases

OBJECTIVES

To bring heightened awareness to a condition, autoimmune gastritis (AIG), which is a well-established entity in adults; however, rarely described in pediatrics. Currently, the literature describes AIG in pediatric patients who also suffer from other autoimmune disorders, which precedes the diagnosis of AIG, and often presents with unexplained anemia. Additionally, there have been case reports describing patients with immunodeficiencies and AIG, which progress to gastric adenocarcinoma. AIG is a histopathologic diagnosis, demonstrating chronic inflammatory process with loss of parietal cells with or without intestinal metaplasia and enterochromaffin-like cell hyperplasia. Management of these patients includes nutritional replacement as well as routine surveillance endoscopy with biopsy in search of metaplastic and dysplastic changes.

METHODS

We queried the pathology database at Children's Hospital Los Angeles (CHLA) for cases with a final diagnosis of AIG and for those with a differential diagnosis that includes AIG in the diagnostic comment. All cases that were identified were selected as long as they did not only meet the histopathologic criteria, but also the biochemical criteria for this condition.

RESULTS

Of the 3 patients, 2 were referred to gastroenterology for the evaluation of iron-deficiency anemia in the context of diabetes mellitus and Addison's disease; and diabetes mellitus and Hashimoto's thyroiditis. AIG was confirmed on the biopsies, which showed a reduction in parietal cell mass, pseudopyloric metaplasia and enterochromafin-like cell hyperplasia. Both patients were treated with iron replacement therapy. The third patient presented with symptomatic anemia and diagnosed with pernicious anemia without other autoimmune disorders. She was successfully treated with oral vitamin supplementation. In this case, serial gastric biopsies demonstrated stable intestinal metaplasia without evidence of dysplasia.

CONCLUSION

Although AIG is rare in children, pediatric gastroenterologists and pathologists should have a heightened suspicion for this entity in those patients with a history of autoimmune disorders and/or pernicious anemia.

Population-based estimates of humoral autoimmunity from the U.S. National Health and Nutrition Examination Surveys, 1960-2014

Objective

Based on US National Health and Nutrition Examination Survey (NHANES) data, we attempted to provide an unbiased, population-based estimate of autoantibody prevalence overall and by age and sex.

Methods

US autoantibody prevalence estimates for detectable rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, anti-transglutaminase, anti-endomysial, anti-GAD65, antinuclear autoantibodies, and autoantibodies to extractable nuclear antigens were estimated from the 1960–1962 National Health Examination Survey, NHANES III (1988–1994), and the NHANES 1999–2014 cross-sectional surveys. Survey design variables and sample weights were used to account for differential probabilities of selection within the complex survey design. Data analysis used SAS^TM and SUDAAN^™ software. US Census Bureau data were used to estimate the absolute numbers of persons with autoantibodies.

Results

NHANES III data show that the overall US prevalence of having a detectable serum autoantibody is substantial in adults, in both women and men. Thyroid autoantibodies were present in 18% of US adults (31 million persons) including 10% of younger adults and 25% of older persons. Overall autoantibody prevalences increased significantly with age: 32% of US adults 60+ years of age (12.8 million persons) had at least one of the four autoantibodies rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, or anti-tissue transglutaminase. Older women had higher levels of autoantibodies, but this was a relative difference. Autoantibody prevalence in both sexes was substantial (women 39%; men 22%). Fourteen percent of adults 60+ years of age have multiple autoantibodies.

Conclusions

Autoantibodies are present in a significant fraction of the general population, especially in older adults and women relative to men. Although all known clinically significant autoantibodies were not analyzed, these data provide an important population perspective on the scope and magnitude of humoral autoimmunity in the US. This is vital for prevention efforts to reduce autoimmune disease and helps clarify the potential impact of autoimmunity on the general population.

Thyro-entero-gastric autoimmunity: Pathophysiology and implications for patient management

The association between autoimmune atrophic gastritis and thyroid disorders has been observed since the early 1960s and the expression "thyrogastric syndrome" was coined to indicate the presence of thyroid autoantibodies or autoimmune thyroid disease in patients with pernicious anemia, a late clinical stage of autoimmune atrophic gastritis. More recently, it was confirmed that autoimmune thyroid disorders, in particular Hashimoto's thyroiditis, may be frequently associated with other organ-specific, immune-mediated disorders, such as autoimmune atrophic gastritis or celiac disease. The association of Hashimoto's thyroiditis with autoimmune atrophic gastritis or celiac disease in adult patients is currently considered part of the polyglandular autoimmune syndromes which include several autoimmune disorders associated with an autoaggressive impairment of endocrine glands. From a clinical point of view, the thyro-entero-gastric autoimmunity may lead to potentially serious consequences like anemia, micronutrients deficiencies, and drugs malabsorption, as well as to an increased risk for malignancies. These alterations may frequently present in an underhand manner, with consequent diagnostic and treatment delays. Many aspects of the association between thyroid, gastric and intestinal autoimmune diseases still await clarification. The present review focuses on the embryological, genetic and pathophysiological aspects of thyro-entero-gastric autoimmunity. In particular, the current diagnostic criteria of autoimmune thyroid disease, autoimmune atrophic gastritis, and celiac disease are reviewed, along with the evidences for their association in poly-autoimmunity syndromes. The benefits of proactive screening of autoimmune thyroid disorders in patients with autoimmune gastritis or enteropathy and viceversa are also discussed.

Chronic atrophic gastritis: Natural history, diagnosis and therapeutic management. A position paper by the Italian Society of Hospital Gastroenterologists and Digestive Endoscopists [AIGO], the Italian Society of Digestive Endoscopy [SIED], the Italian Society of Gastroenterology [SIGE], and the Italian Society of Internal Medicine [SIMI]

Chronic atrophic gastritis (CAG) is an underdiagnosed condition characterised by translational features going beyond the strict field of gastroenterology as it may manifest itself by a variable spectrum of gastric and extra-gastric symptoms and signs. It is relatively common among older adults in different parts of the world, but large variations exist. Helicobacter pylori-related CAG [multifocal] and autoimmune CAG (corpus-restricted) are apparently two different diseases, but they display overlapping features. Patients with cobalamin and/or iron deficiency anaemia or autoimmune disorders, including autoimmune thyroiditis and type 1 diabetes mellitus, should be offered screening for CAG. Pepsinogens, gastrin-17, and anti-H. pylori antibodies serum assays seem to be reliable non-invasive screening tools for the presence of CAG, helpful to identify individuals to refer to gastroscopy with five standard gastric biopsies in order to obtain histological confirmation of diagnosis. Patients with CAG are at increased risk of developing gastric cancer, and they should be estimated with histological staging systems (OLGA or OLGIM). H. pylori eradication may be beneficial by modifying the natural history of atrophy, but not that of intestinal metaplasia. Patients with advanced stages of CAG (Stage III/IV OLGA or OLGIM) should undergo endoscopic surveillance every three years, those with autoimmune CAG every three-five years. In patients with CAG, a screening for autoimmune thyroid disease and micronutrient deficiencies, including iron and vitamin B₁₂, should be performed. The optimal treatment for dyspeptic symptoms in patients with CAG remains to be defined. Proton pump inhibitors are not indicated in hypochlorhydric CAG patients.

Gastric cancer in autoimmune gastritis: A case-control study from the German centers of the staR project on gastric cancer research

Objectives

Patients with autoimmune gastritis (AIG) are reported to have an increased risk of developing gastric cancer (GC). In this study, we assess the characteristics and outcomes of GC patients with AIG in a multicenter case-control study.

Methods

Between April 2013 and May 2017, patients with GC, including cancers of the esophagogastric junction (EGJ) Siewert type II and III, were recruited. Patients with histological characteristics of AIG were identified and matched in a 1:2 fashion for age and gender to GC patients with no AIG. Presenting symptoms were documented using a self-administered questionnaire.

Results

Histological assessment of gastric mucosa was available for 572/759 GC patients. Overall, 28 (4.9%) of GC patients had AIG (67 ± 9 years, female-to-male ratio 1.3:1). In patients with AIG, GC was more likely to be localized in the proximal (i.e. EGJ, fundus, corpus) stomach (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.0–7.1). In GC patients with AIG, pernicious anemia was the leading clinical sign (OR 22.0, 95% CI 2.6–187.2), and the most common indication for esophagogastroduodenoscopy (OR 29.0, 95% CI 7.2–116.4). GC patients with AIG were more likely to present without distant metastases (OR 6.2, 95% CI 1.3–28.8) and to be treated with curative intention (OR 3.0, 95% CI 1.0–9.0). The five-year survival rates with 95% CI in GC patients with and with no AIG were 84.7% (83.8–85.6) and 53.5% (50.9–56.1), respectively (OR 0.25, 95% CI 0.08–0.75, p = 0.001).

Conclusions

Pernicious anemia leads to earlier diagnosis of GC in AIG patients and contributes significantly to a better clinical outcome.

High frequency of anti-parietal cell antibody (APCA) and intrinsic factor blocking antibody (IFBA) in individuals with severe vitamin B12 deficiency – an observational study in primary care patients

Background

Vitamin B12 deficiency is common worldwide and is also linked to several diseases including autoimmune atrophic gastritis (AAG). The presence of anti-parietal cell antibodies (APCA) and/or intrinsic factor blocking antibodies (IFBA) is indicative of AAG that may develop into pernicious anemia. Both conditions are known to be associated with an increased risk of gastric carcinoma. The aim of this study was to estimate the frequency of individuals positive for APCA and IFBA antibodies in primary care patients with severe vitamin B12 deficiency.

Methods

An observational study was designed and 5468 consecutive patients from primary care with a request for vitamin B12 status were included and add-on testing for APCA and IFBA that were automatically registered if severe vitamin B12 deficiency was identified (<73.8 pmol/L). For patients included in the intervention, study demographic data, mean corpuscular volume (MCV) and hemoglobin values were collected.

Results

Seventy-seven patients with severe vitamin B12 deficiency were identified and out of these 44 (57%) presented with antibodies to APCA and 11 (14%) to IFBA, 25 (32.5%) had anemia, and 25 (32.5%) had macrocytosis. The majority of APCA and/or IFBA positive patients were found in the age group >70 years. Both anemia and macrocytosis were more common among APCA positive patients but the association was not statistically significant, neither was the correlation between IFBA status and anemia and/or macrocytosis. Among the patients with anemia, 10 (39%) had macrocytosis, although the rate of macrocytosis among patients with or without anemia did not differ significantly.

Conclusions

The automated analysis strategy of measuring antibodies to APCA and IFBA in patients with severe vitamin B12 deficiency, efficiently detected positivity in more than 60% the patients. The result point to the presence of a high rate of otherwise undetected AAG and the potential clinical utility of APCA and IFBA as markers in primary care.