UNASSIGNED: Pernicious anemia (PA) is believed to be highly prevalent in Western countries but has rarely been reported in China. The study explores whether PA, an autoimmune disease, is an uncommon cause of cobalamin (vitamin B12) deficiency anemia in China.
UNASSIGNED: Clinical and hematological data were collected from 90 cobalamin deficiency-caused megaloblastic anemia (MA) patients between July 2014 and December 2021. Through anti-intrinsic factor antibody (IFA) and anti-parietal cell antibody (PCA) testing, PA was distinguished from other causes of cobalamin deficiency leading to MA. Meanwhile, 30 healthy controls (HCs) were included to estimate the positive rates of IFA and PCA.
UNASSIGNED: Of the 30 HCs, only one tested positive for IFA, and all 30 tested negative for PCA. Among the 90 patients with cobalamin deficiency-caused MA, 76.7% were positive for IFA, and 47.8% were positive for PCA; a total of 76 patients (84.4%) were diagnosed with PA. The mean follow-up time was 41.0 ± 16.3 months. During the follow-up period, no case relapsed among the continuous cobalamin-supply treatment patients, while 24.4% of patients relapsed due to the interruption of maintenance cobalamin-supplement therapy (the median recurrence time was 54.0 ± 17.7 months).
UNASSIGNED: The proportion of PA in cobalamin deficiency-caused MA patients in Hainan province was higher than 80%, which was more common than expected. Therefore, screening for IFA, PCA, endoscopic biopsy, and thyroid-related parameters are recommended for all cobalamin deficiency-caused MA patients. Furthermore, maintenance cobalamin-supplement therapy is important for PA patients.
This research examines pernicious anemia (PA), a type of anemia caused by vitamin B12 deficiency, which has been widely reported in Western countries but is less known in China. The study focuses on determining if PA is also a significant cause of this deficiency in Hainan, China. Researchers gathered data from patients with megaloblastic anemia (a blood disorder) due to lack of vitamin B12, comparing them with healthy individuals to see how common PA is. The findings reveal that a very high percentage of the patients studied have PA, much higher than expected. This suggests that PA is not as rare in this region of China as previously thought. The study also highlights the importance of continuous treatment with vitamin B12 to prevent the recurrence of the anemia. Based on these results, the researchers recommend that all patients with vitamin B12 deficiency should be tested for PA and continuously receive vitamin B12 supplements to maintain their health once diagnosed with PA. This strategic insight is of paramount importance to medical practitioners in China, potentially paving the way for enhanced clinical management protocols for individuals afflicted by this ailment.

This case report presents a male in his 30s with pernicious anaemia, initially diagnosed with autoimmune haemolytic anaemia and thrombocytopenia. Despite improvement with treatment, he developed bilateral leg weakness and numbness, ultimately diagnosed as peripheral neuropathy. Further investigations revealed a spectrum of haematological and neurological manifestations associated with B12 deficiency, challenging the typical illness script of pernicious anaemia. This report underscores the importance of recognising variations in clinical presentation and highlights the need for expanded illness scripts to guide accurate diagnosis and management.

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.

Vitamin B12 is essential for various bodily functions, and its deficiency may cause hematological manifestations. We report a case of a previously healthy 65-year-old female who was admitted to our hospital with reduced sense of taste and painful tongue. The serum level of vitamin B12 was decreased. However, her complete blood count did not show any evidence of macrocytosis, instead, her mean corpuscular volume was low. Gene sequencing indicated an β-thalassemia minor and that probably masked the megaloblastic features of vitamin B12 deficiency.

COVID-19, a global epidemic of infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), not only initially refers to acute manifestations but also chronic symptoms known as Long COVID-19. Long COVID-19 represents a significant burden to healthcare systems worldwide. This syndrome encompasses a wide range of continuing health problems with variable durations and consequences for patients\' everyday lives. A notable aspect of Long COVID-19 is the emergence of new-onset autoimmune diseases that could be triggered in predisposed patients with altered immune responses. Common autoimmune conditions that arise in post-COVID patients include autoimmune hemolytic anemia, immune thrombocytopenic purpura, autoimmune thyroid diseases, Kawasaki disease, Guillain-Barre syndrome, etc., but with unclear evidence of associated disease occurrence. We present a case of a female rheumatoid arthritis patient who developed autoimmune thyroid disease, latent autoimmune diabetes of adults (LADA), and pernicious anemia after SARS-CoV-2 infection.

Megaloblastic anemia (MBA) is a reversible metabolic disorder that responds well to vitamin B12 supplementation. It contrasts with myelodysplastic syndrome (MDS), an irreversible neoplastic condition characterized by hematopoietic stem cell abnormalities. To date, no association has been identified between these two distinct etiologies, and they are considered independent diseases. However, despite their distinct classifications, both conditions present macrocytic anemia, similar bone marrow findings, and sometimes have common chromosomal abnormalities, which can lead to occasional misdiagnoses. Herein, we present a patient initially diagnosed with pernicious anemia (PA) who showed improvement with replacement therapy but subsequently became resistant to treatment and eventually developed MDS. Quantitative assessment of Wilm\'s tumor-1 (WT1) mRNA has emerged as a valuable tool for gauging MDS disease status and distinguishing it from related disorders, such as aplastic anemia. In our investigation of 30 patients with MBA, we explored WT1 mRNA expression. We observed its presence in 10 patients with PA, which suggests a potential link between PA and hematopoietic tumors.

Pernicious anemia, stemming from Vitamin B12 deficiency and autoimmune processes affecting intrinsic factor production, presents challenges in early diagnosis due to vague initial symptoms. This case report introduces a unique occurrence of pernicious anemia-induced peripheral neuropathy in a patient with concurrent HLA-B27 arthropathy, highlighting the complex interplay of autoimmune mechanisms. While HLA-B27 is not typically associated with pernicious anemia, the case underscores the importance of exploring specific HLA haplotypes in understanding the nuanced manifestation of autoimmune disorders. Comprehensive screening for anti-intrinsic factor and anti-parietal cell antibodies is crucial in individuals with signs of pernicious anemia, especially those with a history of HLA-B27 arthropathy, guiding tailored management strategies. This report contributes to the ongoing exploration of the intricate autoimmune landscape in pernicious anemia.

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.

The causes and risk factors of vitamin B12 deficiency are many and varied. Importantly, they vary considerably across the lifespan, from infancy to old age. The complexity of the physiology of vitamin B12 bespeaks the myriad of possible causes of deficiency and possible disruptions of its functional integrity. These lead ultimately to the pathobiological effects witnessed in deficiency of this fascinating micronutrient. This brief overview of the multiplicity of mechanisms that can result in vitamin B12 deficiency, and the panoply of its manifestations explores the underlying reasons for the protean presentations of the disease. As the human organism progresses through the chronology and milestones of age, various susceptibility factors arise resulting from the interplay of environmental and genetic factors. Acting independently and in concert, these factors produce the common denominator of vitamin B12 deficiency. However, the rate at which such deficiency develops and the way in which it presents clinically vary widely, subject to such influences as genetic variability, end-organ susceptibility, and concomitant micronutrient status. Some examples of unusual cases of vitamin B12 deficiency are described. Much has been learned about the last of the numbered vitamins in almost a century. Much yet remains to be discovered.

UNASSIGNED: In the 1940s to 1950s, high-dose folic acid supplements (>5 mg/d) were used clinically to reverse the megaloblastic anemia of vitamin B12 deficiency caused by pernicious anemia. However, this treatment strategy masked the underlying B12 deficiency and possibly exacerbated its neuropathological progression. The issue of masking and exacerbating B12 deficiency has recently been rekindled with the institution of folic acid fortification and the wide-spread use of folic acid supplements.
UNASSIGNED: The objectives of this review are to describe clinical and epidemiological evidence that excess folic acid exacerbates B12 deficiency, to summarize a hypothesis to explain this phenomenon, and to provide guidance for clinicians.
UNASSIGNED: Cognitive function test scores are lower and blood homocysteine and methylmalonic acid concentrations are higher in people with low B12 and elevated folate than in those with low B12 and nonelevated folate. High-dose folic acid supplementation in patients with pernicious anemia or epilepsy cause significant reductions in serum B12. It is hypothesized that high-dose folic acid supplements cause depletion of serum holotranscobalamin and thus exacerbate B12 deficiency.
UNASSIGNED: The evidence for excess folic acid exacerbating B12 deficiency is primarily correlative or from uncontrolled clinical observations, and the hypothesis to explain the phenomenon has not yet been tested. Nonetheless, the evidence is sufficiently compelling to warrant increased vigilance for identifying B12 deficiency in at risk individuals, including older adults and others with low B12 intake or conditions that are associated with B12 malabsorption, who also ingest excessive folic acid or are prescribed folic acid in high doses.
Plain language titleExcess Folic Acid and Vitamin B12 Deficiency: Clinical Implications?Plain language summaryIt has been known for many decades that high doses of the B vitamin supplement, folic acid, can alleviate the anemia of vitamin B12 deficiency, at least temporarily. However, by alleviating the anemia, such folic acid supplements were said to “mask” the underlying vitamin B12 deficiency, thus allowing neurological damage to continue or possibly be exacerbated. Consequently, treating vitamin B12 deficiency with high dose folic acid was discontinued in the 1970s. The issue of whether folic acid supplements can exacerbate vitamin B12 deficiency reemerged in the 1990s with folic acid fortification of cereals and grains in the United States and Canada (and now in over 80 countries around the world) to prevent spina bifida and other birth defects. This narrative review summarizes the results of studies that have assessed the relationships between folic acid and folate and vitamin B12 status in patients and in populations. A recent hypothesis on how folic acid might exacerbate vitamin B12 deficiency is summarized, and recommendations to clinicians are made for increased vigilance in assessing vitamin B12 status in certain groups at risk of vitamin B12 deficiency, including older adults, people with gastrointestinal issues and other factors that cause vitamin B12 malabsorption, people with unexplained neurological problems, and people who follow vegan or vegetarian diets which are naturally low in vitamin B12.