Pernicious anemia: Pathophysiology and diagnostic difficulties

Clinical characteristics and outcomes of pediatric patients with autoimmune gastritis

OBJECTIVES

Autoimmune gastritis (AIG) is a rare chronic inflammatory disorder with potential long-term sequelae including gastric neoplasia. There is limited data on the natural history of pediatric AIG. We aimed to characterize the clinical course and outcomes of children with AIG.

METHODS

This was a multicenter retrospective study that included pediatric patients diagnosed with AIG between January 1, 2000 and December 31, 2021. Diagnosis of AIG was based on the demonstration of histological corpus-predominant atrophic gastritis, with or without positive antiparietal cell (APCA) or anti-intrinsic factor (IF) antibodies. Demographic, clinical, laboratory, endoscopic, and histologic data were retrieved, along with follow-up data.

RESULTS

Thirty-three patients, (23 females, [69.7%], median age 12.0 [interquartile range 7.0-15.0] years at diagnosis) were identified. Twenty-two patients (66.7%) had positive APCA and/or anti-IF serology. The most common presenting manifestation was iron deficiency anemia (75%), and accompanying autoimmune disorders were significantly more common in patients with positive serology (62% vs. 18%, p < 0.05). Pseudo-pyloric or intestinal-type metaplasia was present at diagnosis in eight patients (24%), and 11 additional patients (33%) developed metaplasia during a median follow-up time of 27 (17.5-48.3) months. One patient developed a type 1 gastric neuroendocrine tumor. Helicobacter pylori was identified in only one patient, while two patients had prior eradication. Endoscopic and histologic improvements weren't identified in any patients.

CONCLUSIONS

AIG should be considered in patients with autoimmunity and resistant iron-deficiency anemia. H. pylori infection may not be associated with pediatric AIG. The development of neuroendocrine tumor in one patient, and the high rates of metaplasia, highlight the importance of surveillance.

Oral manifestations of vitamin B12 deficiency associated with pernicious anemia: A case report

INTRODUCTION AND IMPORTANCE

Vitamin B12 deficiency can manifest through various oral manifestations such as glossitis, glossodynia, recurrent ulcers, cheilitis, dysgeusia, lingual paresthesia, burning sensations, and pruritus. These oral signs can serve as early indicators of systemic conditions such pernicious anemia.

CASE PRESENTATION

A 67 year old northern African female presented at the oral surgery service with complaints of a sore mouth and difficulty eating certain types of food. Her medical history revealed hypothyroidism and no history of gastrectomy. She was diagnosed with pernicious anemia in 2014 and is under hydroxocobalamin injection 5000μg/month since then. Dental history indicated extraction of all teeth, and in 2014, the patient was diagnosed with oral lichen planus. There were no contributory oral habits. Intraoral examination revealed a band like erythematous lesion on the palate with two superficial ulcerations, diagnosed as related to her pernicious anemia. The patient was prescribed a mouthwash containing sodium bicarbonate and corticosteroid to reduce inflammation and alleviate pain. A low level laser therapy was also considered to reduce the burning sensations.

CLINICAL DISCUSSION

Pernicious anemia (PA) is an autoimmune disease characterized by the gradual atrophy of the gastric mucosa, predominantly affecting the body and fundus of the stomach, leading to vitamin B12 deficiency. Its insidious onset often masks its presence. Patients have no anemic symptoms. However, they can present with oral manifestations related to vitamin B12 deficiency. Those oral signs can precede hematological symptoms helping in early diagnosis of PA.

CONCLUSION

Dentists and other oral health care providers must be aware of this condition and its oral manifestations. Investigating vitamin B12 levels should be considered in patients presenting with oral ulcers, oral erythema or burning sensations without an apparent origin.

Causal inference between pernicious anemia and cancers: a bidirectional two-sample mendelian randomization analysis

BACKGROUND

Observational study investigated the association between pernicious anemia (PA) and cancers. However, with the exception of gastric cancer, the results are mostly contradictory. The purpose of this study was to investigate the potential causal relationship between PA and cancers through bidirectional two-sample Mendelian randomized (MR) analysis.

METHODS

The European sample FinnGen project provided the genetic summary data for PA and 20 site-specific cancers. This bidirectional two-sample MR design mainly used the inverse variance weighting (IVW) method to evaluate the causal relationship between PA and cancer risk. Benjamini-Hochberg correction was performed to reduce the bias caused by multiple tests.

RESULTS

Our study shows that there was a causal relationship between PA and gastric cancer, prostate cancer, testicular cancer and malignant melanoma of skin, and there was a reverse causal relationship between prostate cancer or gastric cancer and PA (P < 0.05). After Benjamini-Hochberg correction test, there was still a causal correlation between PA and gastric or prostate cancer (P' < 0.05), while there was only an implied causal association between PA and testicular cancer and malignant melanoma of skin (P'> 0.05). There was still a reverse causal relationship between gastric cancer and PA (P'< 0.05), while prostate cancer shows an implied reverse causal relationship(P'> 0.05). In addition, MR-Egger and MR-PRESSO tests showed no significant horizontal pleiotropy.

CONCLUSIONS

PA may be genetically associated with testicular cancer, prostate cancer, gastric cancer, and malignant melanoma of skin.

Vitamin B12 deficiency presenting as neck pain and cervical radiculopathy

Vitamin B12 is required for the formation of haematopoietic cells and the synthesis of myelin. Deficiency typically presents with fatigue and megaloblastic anaemia. Prolonged deficiency can cause neurological symptoms such as paresthesia, which can progress to subacute combined degeneration of the spinal cord. We describe an unusual presentation of B12 deficiency in a young man who was initially diagnosed and treated for cervical radiculopathy. This case highlights the challenges of diagnosing B12 deficiency in patients with neurologic but without haematologic, abnormalities. While the current incidence of B12 deficiency in developed countries is low, cases are likely to rise with the increased adoption of veganism. Clinicians should be aware of the variable presentations of B12 deficiency because delayed diagnosis and treatment increases morbidity and can cause irreversible neurological deficits.

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

Pernicious Anemia With Spuriously Normal B12 Levels

We present a 29-year-old man admitted to our hospital with fatigue for two months of duration and recent palpitations, lightheadedness, blurred vision and nausea. Workup showed pancytopenia with severe macrocytic anemia, laboratory and blood smear features of hemolysis, low reticulocyte percentage and a negative direct Coombs test. B12 and folate levels were normal. As bone marrow aspirate was suggestive of megaloblastic anemia and upper endoscopy showed atrophic gastritis, we ordered homocysteine (elevated) and intrinsic factor (IF) antibodies (positive). The workup led to the diagnosis of pernicious anemia with spuriously normal B12 levels. Replacement therapy allowed a rapid recovery. We highlight that the presence of IF antibodies can interfere with the competitive binding assays commonly used to measure B12 levels.

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.

Effects of vitamin B12 deficiency on risk and outcome of ischemic stroke

Ischemic stroke is the most prevalent form of stroke and has a high incidence in older adults, characterized by high morbidity, mortality, disability, and recurrence rate. Vitamin B₁₂ deficiency is prevalent in the elderly and has been reported to be associated with ischemic stroke. The mechanisms maybe include the disorder of methylation metabolism, accumulation of toxic metabolites, immune dysfunction, affecting gut microbial composition and gut-brain immune homeostasis, and toxic stress responses to the brain. Vitamin B₁₂ deficiency may lead to cerebral artery atherosclerosis, change myelination, influence the metabolism and transmission between nerve tissue, and ultimately causes the occurrence and development of ischemic stroke. This paper reviews the correlation between vitamin B₁₂ deficiency and ischemic stroke, looking forward to improving clinicians' understanding and providing new therapeutic directions for ischemic stroke.

A novel transdermal delivery route for energy supplements: Electrospun chitosan/polyvinyl alcohol nanofiber patches loaded with vitamin B12

Nanofibrous patches have attracted much attention as a solution to resolve drug delivery challenges. In this study, vitamin B₁₂- loaded polyvinyl alcohol (PVA)/chitosan (Cs) nanofiber patch (NFP) was electrospun and cross-linked by glutaraldehyde (GA). The physicochemical properties of the nanofiber patches were assessed by morphological studies, FTIR analysis, hydrophilicity test, mechanical tests, and in-vitro evaluations including biodegradability, MTT assay, and cumulative release test of vitamin. In-vivo studies were also carried out by measuring vitamin B₁₂ levels in the bloodstream and conducting histopathology studies on the animal models. The results showed that the mean diameter of Cs/PVA/B₁₂ and cross-linked patch were approximately 207 and 256 nm, respectively. Cross-linking of NFP led to the lower, slower, and more continuous release of the vitamin with a slight decrease in biodegradability, and an increase in the mechanical properties of the nanofiber patches. Furthermore, the cytocompatibility assay, MTT, and in vivo results revealed no cytotoxicity of Cs/PVA/B₁₂ NFP towards L929 cell line. No lesion or tissue damage was observed in the skin tissue of the animal models wearing these skin patches. Therefore, B₁₂-loaded NFP can be introduced as a potential candidate for commercial transdermal routes.

Examining the Diagnosis and Treatment Experiences of People Living With Autoimmune Gastritis and Pernicious Anemia

There is limited research evaluating the diagnosis and treatment of patients with autoimmune gastritis (AIG) and pernicious anemia (PA). We used a 2-phase data collection process to examine the literature and individual patient accounts. Phase one comprised a systematically conducted literature review focusing on diagnosis and treatment, relationships with healthcare practitioners and health-related quality of life (HRQOL). Phase two involved analysis of individual accounts via posts in online patient forums. We identified 6 main themes: the diagnosis journey, seeking treatment, patient-provider relationships, HRQOL, patient disempowerment, and the "expert patient." Our findings confirm significant knowledge gaps concerning AIG/PA across the healthcare community. These have a cascading effect starting with delays in diagnosis and poor treatment protocols and often lead to complete withdrawal from care seeking. The establishment of standard consensus guidelines and improved clinical awareness should be urgently addressed. Interventions that better help patients understand their illness are also needed to improve psychological health. Without these changes disengagement from health systems, and poor health outcomes, will continue for this population group.

Vitamin B12 (Cobalamin): Its Fate from Ingestion to Metabolism with Particular Emphasis on Diagnostic Approaches of Acquired Neonatal/Infantile Deficiency Detected by Newborn Screening

Acquired vitamin B12 (vB12) deficiency (vB12D) of newborns is relatively frequent as compared with the incidence of inherited diseases included in newborn screening (NBS) of different countries across the globe. Infants may present signs of vB12D before 6 months of age with anemia and/or neurologic symptoms when not diagnosed in asymptomatic state. The possibility of identifying vitamin deficient mothers after their pregnancy during the breastfeeding period could be an additional benefit of the newborn screening. Vitamin supplementation is widely available and easy to administer. However, in many laboratories, vB12D is not included in the national screening program. Optimized screening requires either second-tier testing or analysis of new urine and blood samples combined with multiple clinical and laboratory follow ups. Our scope was to review the physiologic fate of vB12 and the pathobiochemical consequences of vB12D in the human body. Particular emphasis was put on the latest approaches for diagnosis and treatment of vB12D in NBS.

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.

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.

Autoimmune Disease Classification Based on PubMed Text Mining

Autoimmune diseases (AIDs) are often co-associated, and about 25% of patients with one AID tend to develop other comorbid AIDs. Here, we employ the power of datamining to predict the comorbidity of AIDs based on their normalized co-citation in PubMed. First, we validate our technique in a test dataset using earlier-reported comorbidities of seven knowns AIDs. Notably, the prediction correlates well with comorbidity (R = 0.91) and validates our methodology. Then, we predict the association of 100 AIDs and classify them using principal component analysis. Our results are helpful in classifying AIDs into one of the following systems: (1) gastrointestinal, (2) neuronal, (3) eye, (4) cutaneous, (5) musculoskeletal, (6) kidneys and lungs, (7) cardiovascular, (8) hematopoietic, (9) endocrine, and (10) multiple. Our classification agrees with experimentally based taxonomy and ranks AID according to affected systems and gender. Some AIDs are unclassified and do not associate well with other AIDs. Interestingly, Alzheimer’s disease correlates well with other AIDs such as multiple sclerosis. Finally, our results generate a network classification of autoimmune diseases based on PubMed text mining and help map this medical universe. Our results are expected to assist healthcare workers in diagnosing comorbidity in patients with an autoimmune disease, and to help researchers in identifying common genetic, environmental, and autoimmune mechanisms.

Characterization of Gastric Tissue-Resident T Cells in Autoimmune and Helicobacter pylori-Associated Gastritis

Data regarding the in-depth surface marker profiles of gastric tissue-resident lymphocytes in autoimmune and Helicobacter pylori-associated gastritis are lacking. In this study, we investigated potential differences in lymphocyte composition between these profiles. We enrolled patients with autoimmune (n = 14), active (current infection of H. pylori in the stomach; n = 10), and inactive gastritis (post-eradication of H. pylori; n = 20). Lymphocytes were isolated from the greater curvature of the stomach and lesser curvature of the body and analyzed using flow cytometry. The CD8+/CD3+ and CD4+/CD3+ ratios differed between the samples. Body CD4+/antrum CD4+, which is calculated by dividing the CD4+/CD3+ ratio in the body by that in the antrum, was significantly higher in autoimmune gastritis (3.54 ± 3.13) than in active (1.47 ± 0.41) and inactive gastritis (1.42 ± 0.77). Antrum CD8+/CD4+ in autoimmune gastritis (7.86 ± 7.23) was also higher than that in active (1.49 ± 0.58) and inactive gastritis (2.84 ± 2.17). The area under the receiver operating characteristic curve of antrum CD8+/CD4+ was 0.842, and the corresponding optimal cutoff point was 4.0, with a sensitivity of 71.4% and a specificity of 93.3%. We propose that an antrum CD8+/CD4+ ratio > 4.0 is a potential diagnostic marker for autoimmune gastritis.

"Listen to Your Immune System When It's Calling for You": Monitoring Autoimmune Diseases Using the iShU App

The immune system plays a key role in protecting living beings against bacteria, viruses, and fungi, among other pathogens, which may be harmful and represent a threat to our own health. However, for reasons that are not fully understood, in some people this protective mechanism accidentally attacks the organs and tissues, thus causing inflammation and leads to the development of autoimmune diseases. Remote monitoring of human health involves the use of sensor network technology as a means of capturing patient data, and wearable devices, such as smartwatches, have lately been considered good collectors of biofeedback data, owing to their easy connectivity with a mHealth system. Moreover, the use of gamification may encourage the frequent usage of such devices and behavior changes to improve self-care for autoimmune diseases. This study reports on the use of wearable sensors for inflammation surveillance and autoimmune disease management based on a literature search and evaluation of an app prototype with fifteen stakeholders, in which eight participants were diagnosed with autoimmune or inflammatory diseases and four were healthcare professionals. Of these, six were experts in human–computer interaction to assess critical aspects of user experience. The developed prototype allows the monitoring of autoimmune diseases in pre-, during-, and post-inflammatory crises, meeting the personal needs of people with this health condition. The findings suggest that the proposed prototype—iShU—achieves its purpose and the overall experience may serve as a foundation for designing inflammation surveillance and autoimmune disease management monitoring solutions.

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.