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Acta Bio-medica : Atenei Parmensis Dec 2018Although the actual prevalence of chronic atrophic gastritis is unknown and it is probable that this entity goes largely underdiagnosed, patients in whom diagnosis is... (Review)
Review
Although the actual prevalence of chronic atrophic gastritis is unknown and it is probable that this entity goes largely underdiagnosed, patients in whom diagnosis is established usually present advanced stages of disease. Destruction of parietal cells, either autoimmune-driven or as a consequence of Helicobacter pylori infection, determines reduction or abolition of acid secretion. Hypo/achloridia causes an increase in serum gastrin levels, with an increased risk of the development of neuroendocrine tumors. Microcytic, hypochromic anemia frequently precedes the development of megaloblastic, vitamin B12-associated anemia. Moreover, vitamin B12 deficiency,may cause elevation of homocysteine, with an increase in the cardiovascular risk, and may be associated with neurological manifestations, mainly characterized by spinal cord demyelination and atrophy, with ensuing sensory-motor abnormalities. Gastrointestinal manifestations seem to be associated with non-acid reflux and tend to be non-specific.
Topics: Achlorhydria; Anemia, Pernicious; Autoimmune Diseases; Chronic Disease; Demyelinating Diseases; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Hyperhomocysteinemia; Parietal Cells, Gastric; Symptom Assessment
PubMed: 30561424
DOI: 10.23750/abm.v89i8-S.7921 -
Discovery Medicine 2019Pernicious anemia (PA), the commonest cause of cobalamin deficiency (CD) in the world, is an autoimmune disease of multifactorial origin and is characterized by chronic... (Review)
Review
Pernicious anemia (PA), the commonest cause of cobalamin deficiency (CD) in the world, is an autoimmune disease of multifactorial origin and is characterized by chronic atrophic gastritis (CAG) and defective absorption of cobalamin from the terminal ileum due to interference by the intrinsic factor (IF) antibodies. PA-related CD is a lengthy process, which if untreated, can lead to irreversible hematological and neurological sequelae. Although safe and effective therapy is available and the management of PA is straightforward, the diagnosis of PA can be extremely difficult to obtain due to myriad and diverse clinical presentations, frequently coexisting diseases, and limitations of currently available diagnostic tests. Diagnostic dilemmas may occur when PA patients present with normal or spuriously high serum cobalamin levels, dysplastic features of ring sideroblasts in the bone marrow (BM), hemolysis, and concomitant diseases such as iron deficiency or thalassemia. Herein, the author discusses an overview of diagnostic difficulties, with regards to morphological mimics, coexisting diseases, limitations of currently available tests, and how to diagnose PA in the era of imperfect laboratory tests.
Topics: Anemia, Pernicious; Autoantibodies; Biomarkers; Hematologic Tests; Humans
PubMed: 32053765
DOI: No ID Found -
Blood May 2020
Topics: Adult; Anemia, Pernicious; Female; Humans; Prognosis; Vitamin B 12; Vitamin B 12 Deficiency; Vitamin B Complex
PubMed: 32379881
DOI: 10.1182/blood.2020005344 -
Frontiers in Molecular Biosciences 2016Vitamin B12 (cobalamin, Cbl, B12) is an indispensable water-soluble micronutrient that serves as a coenzyme for cytosolic methionine synthase (MS) and mitochondrial... (Review)
Review
Vitamin B12 (cobalamin, Cbl, B12) is an indispensable water-soluble micronutrient that serves as a coenzyme for cytosolic methionine synthase (MS) and mitochondrial methylmalonyl-CoA mutase (MCM). Deficiency of Cbl, whether nutritional or due to inborn errors of Cbl metabolism, inactivate MS and MCM leading to the accumulation of homocysteine (Hcy) and methylmalonic acid (MMA), respectively. In conjunction with total B12 and its bioactive protein-bound form, holo-transcobalamin (holo-TC), Hcy, and MMA are the preferred serum biomarkers utilized to determine B12 status. Clinically, vitamin B12 deficiency leads to neurological deterioration and megaloblastic anemia, and, if left untreated, to death. Subclinical vitamin B12 deficiency (usually defined as a total serum B12 of <200 pmol/L) presents asymptomatically or with rather subtle generic symptoms that oftentimes are mistakenly ascribed to unrelated disorders. Numerous studies have now established that serum vitamin B12 has limited diagnostic value as a stand-alone marker. Low serum levels of vitamin B12 not always represent deficiency, and likewise, severe functional deficiency of the micronutrient has been documented in the presence of normal and even high levels of serum vitamin B12. This review discusses the usefulness and limitations of current biomarkers of B12 status in newborn screening, infant and adult diagnostics, the algorithms utilized to diagnose B12 deficiency and unusual findings of vitamin B12 status in various human disorders.
PubMed: 27446930
DOI: 10.3389/fmolb.2016.00027 -
Cleveland Clinic Journal of Medicine Jan 2022
Topics: Anemia, Megaloblastic; Humans; Vitamin B 12; Vitamin B 12 Deficiency; Vitamins
PubMed: 34983795
DOI: 10.3949/ccjm.89a.21041 -
Internal Medicine (Tokyo, Japan) Apr 2021
Topics: Glossitis; Humans; Tongue; Vitamin B 12; Vitamin B 12 Deficiency
PubMed: 33162481
DOI: 10.2169/internalmedicine.6004-20