From the Guidelines
Pernicious anemia, also known as Vitamin B12 deficiency anemia, is a condition that requires immediate treatment with hydroxocobalamin 1 mg intramuscularly, following the NICE CKS guidelines to prevent further complications, such as subacute combined degeneration of the spinal cord. This condition occurs due to the body's inability to absorb vitamin B12 from the digestive tract, often caused by a lack of intrinsic factor, a protein produced by stomach cells necessary for B12 absorption 1. The treatment regimen varies depending on the presence of neurological involvement, with patients requiring immediate attention from neurologists and haematologists if symptoms such as unexplained sensory and/or motor and gait symptoms are present 1.
Key Treatment Considerations
- For people with neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered on alternate days until there is no further improvement, then every 2 months 1
- For people with no neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered three times a week for 2 weeks 1
- Maintenance treatment with 1 mg intramuscularly every 2–3 months is necessary for life 1 Without proper treatment, pernicious anemia can lead to severe neurological damage, including peripheral neuropathy, ataxia, dementia, and can be fatal. Regular monitoring of B12 levels and complete blood counts is essential to manage the condition effectively. It is crucial for patients to understand that this is a lifelong condition requiring consistent treatment to prevent serious complications.
From the FDA Drug Label
Pernicious anemia is associated with an increased incidence of carcinoma of the stomach, but this is believed to be related to the underlying pathology and not to treatment with cyanocobalamin. Patients with pernicious anemia should be informed that they will require monthly injections of vitamin B12 for the remainder of their lives. Pernicious anemia, both uncomplicated and accompanied by nervous system involvement.
Pernicious anemia is a condition characterized by a deficiency of Vitamin B12, which can lead to anemia and neurological damage if left untreated. It is often associated with an increased incidence of carcinoma of the stomach. Key features of pernicious anemia include:
- Requirement for monthly Vitamin B12 injections for life
- Increased risk of carcinoma of the stomach
- Potential for neurological involvement 2 3
From the Research
Definition and Causes of Pernicious Anemia
- Pernicious anemia is an autoimmune disease characterized by autoimmune chronic atrophic gastritis (CAG) and cobalamin deficiency (CD) 4.
- It is the most common cause of vitamin B12 (cobalamin) deficiency anemia in the world 4.
- Pernicious anemia occurs in a later stage of autoimmune atrophic gastritis when gastric intrinsic factor deficiency and consequent vitamin B12 deficiency may occur 5.
Clinical Presentations and Complications
- The onset and progression of pernicious anemia is often insidious, and patients may have no anemic symptoms or may become acclimatized to the subtle nature of the disease 4.
- If left untreated, pernicious anemia can result in permanent neurological disability or death 6.
- 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 5.
Diagnosis and Diagnostic Challenges
- Diagnostic challenges remain tangible for many practicing clinicians due to the lack of reliable cobalamin assays to diagnose CD, as well as clinical mimics that simulate many other hematological conditions 4.
- False-normal vitamin B12 results can be obtained with competitive-binding vitamin B12 assays performed on automated biochemistry platforms in patients with pernicious anemia due to the presence of interfering anti-intrinsic factor antibodies in the patient sample 6.
- A functional assay of vitamin B12 (plasma homocysteine or methylmalonic acid) should be checked to further investigate for vitamin B12 deficiency in patients with normal vitamin B12 levels and a high clinical suspicion for deficiency 6.
Treatment and Management
- Treatment of pernicious anemia is based on the administration of parenteral vitamin B12, although other routes of administration (e.g., oral) are currently under study 7.
- Oral treatment of vitamin B12 deficiency is possible whatever the etiology, but it has only been validated in small series 8.
- Parenteral treatment remains indicated for severe neurologic deficits or whenever patient adherence with treatment is doubtful 8.