Vitamin B12 Deficiency Presenting With Microangiopathic Hemolytic Anemia

Pernicious Anemia Unveiled: Unusual Hemolytic Complications and Clinical Implications

Pernicious anemia (PA) is an autoimmune condition resulting in impaired vitamin B12 absorption that commonly presents with gastritis and neurological symptoms. In rare cases, associated vitamin B12 deficiency can contribute to significant red blood cell lysis, and patients can present with PA-induced pseudo-thrombotic microangiopathy (TMA) hemolytic anemia. This case describes a 59-year-old male presenting with a two-week history of gastrointestinal pain with bleeding who had anemia and hemodynamic instability on initial evaluation. After the endoscopy/colonoscopy did not reveal any active sources of bleeding and packed red blood cells failed to stabilize the patient, it was found that he had low serum B12 with anti-intrinsic factor and anti-parietal cell antibodies. A coordinated clinical approach, including parenteral cyanocobalamin and daily oral folic acid supplementation, stabilized the patient, highlighting the importance of distinguishing PA-induced pseudo-TMA from true TMA hemolytic anemia.

Adult Vitamin B12 Deficiency-Associated Pseudo-Thrombotic Microangiopathy: A Systematic Review of Case Reports

Cobalamin-deficient thrombotic microangiopathy or vitamin B12 deficiency presenting as pseudo-thrombotic microangiopathy is a rare disorder that can be misdiagnosed as thrombotic thrombocytopenic purpura. Patients with this condition are at risk of receiving unnecessary plasmapheresis with a potential delay in appropriate therapy with vitamin B12 supplementation. There are no established diagnostic criteria for this condition in clinical practice. We performed a systematic review of case reports published between January 2018 and January 2023 to analyze the clinical characteristics, risk factors, and patterns of laboratory markers to improve the diagnostic criteria for this condition.

A Case Report of Cold Agglutinin Disease, Severe B12 Deficiency, and Pernicious Anemia: A Deadly Coincidence

Anemia is the most common hematological disorder. It is commonly a manifestation of an underlying disease. Its causes are multifactorial, including but not limited to nutritional deficiencies, chronic conditions, inflammatory processes, medications, malignancy, renal dysfunction, hereditary diseases, and bone marrow disorders. We present a case of a patient exhibiting anemia related to cold agglutin disease and severe B12 deficiency secondary to pernicious anemia.

Pseudo-thrombotic microangiopathy due to folate deficiency

Classically, deficiencies of vitamin B12 and folate are associated with megaloblastic anaemia. Additionally, vitamin B12 is able to cause a haemolytic anaemia in the form of pseudo-thrombotic microangiopathy (pseudo-TMA). Here, we present a case of a middle-aged woman with a history of Roux-en-Y gastric bypass who presented with dyspnoea and fatigue and was found to have thrombocytopenia and a non-immune haemolytic anaemia. Work-up for haemolytic uraemic syndrome, thrombotic thrombocytopenic purpura, paroxysmal nocturnal haemoglobinuria, infection, malignancy and autoimmune conditions was unremarkable. Her haemolytic anaemia and thrombocytopenia resolved with folate replenishment. She was diagnosed as likely having pseudo-TMA secondary to folate deficiency.

Beneficial effects of vitamin B12 treatment in pediatric patients diagnosed with vitamin B12 deficiency regarding total-native thiol, oxidative stress, and mononuclear leukocyte DNA damage

Vitamin B₁₂ is involved in biochemical metabolic pathways. B₁₂ deficiency is common in childhood when the need for the vitamin increases and growth and development occur. Various hematological, neurological, psychiatric, and gastrointestinal disorders are observed in its deficiency. In addition, B₁₂ deficiency is associated with oxidative stress and DNA damage. Therefore, the aim of our study is to evaluate oxidative stress, thiol/disulfide homeostasis, and DNA damage pre and post-treatment in children diagnosed with B₁₂ deficiency. A total of 40 children with B₁₂ deficiency were included in the study after the consent form was approved. Blood was drawn from children pre and posttreatment. Hemoglobin (HGB), hematocrit (HCT), and red blood cells (RBC) were measured by autoanalyzer; total antioxidant status (TAS), total oxidant status (TOS), total thiol (TT), and native thiol (NT) were measured by the photometric method, and DNA damage was analyzed by the comet assay method. Oxidative stress index (OSI) and disulfide (DIS) values were calculated. As a result of the experiments, HGB, HCT, and RBC increased with treatment. While TAS, TT, and NT as antioxidant parameters increased; TOS, OSI, and DIS decreased with treatment compared to pretreatment. DNA damage was also found to decrease with treatment. Additionally, these data were statistically significant (p < 0.001). It was found that oxidative stress and DNA damage decreased with oral B₁₂ treatment in children with B₁₂ deficiency, and clinical parameters were also improved.

Chronic Atrophic Gastritis Presenting as Hemolytic Anemia due to Severe Vitamin B12 Deficiency

Vitamin B12 is an essential nutrient which plays an important role in neurological function, hematopoiesis, and DNA synthesis. Low levels usually stem from either poor intake or a malabsorptive process. Presently, the most common cause of vitamin B12 deficiency is food-bound cobalamin malabsorption, which occurs when there is impaired release of vitamin B12 from ingested food due to an outstanding factor preventing the release of the nutrient from its transport protein. Such causes include achlorhydria, gastritis, gastrectomy, or the use of PPIs or antacids. A rarer cause is autoimmune chronic atrophic gastritis, resulting in pernicious anemia. In this disease process, there is destruction of parietal cells and thus a reduction in intrinsic factor, which is essential to the absorption of vitamin B12. Deficiency will result in a variety of abnormalities including but not limited to pancytopenia, paresthesias, and neuropsychiatric symptoms. A rare manifestation of vitamin B12 deficiency is hemolytic anemia, which occurs due to intramedullary and extramedullary dysfunction. This case describes a 46-year-old male with no past medical history who presented with chest pain, fatigue, and progressive weakness, found to have hemolytic anemia, ultimately attributed to vitamin B12 deficiency. Antiparietal cell antibodies and intrinsic factor antibodies (IFA) were both negative. Still, the patient underwent an endoscopy with biopsies of the stomach; pathology was consistent with chronic metaplastic atrophic gastritis. The patient improved with intramuscular vitamin B12 supplementation. This case highlights both a rare cause and presentation of vitamin B12 deficiency. Patients with autoimmune chronic atrophic gastritis should have antiparietal cell or intrinsic factor antibodies. Still, seronegative patients have been reported, like this patient. Additionally, hemolytic anemia secondary to vitamin B12 deficiency is uncommon. The presentation will usually mirror that of a thrombotic microangiopathy (TMA), including hemolytic anemia with schistocytes on peripheral blood smear and thrombocytopenia, as it did in this patient. This clinical entity is described as pseudothrombotic microangiopathy and is crucial to identify in order to prevent the initiation of invasive treatment strategies such as plasmapheresis.