Pernicious Anemia Treatment

Overview

Pernicious anaemia is an autoimmune condition characterised by the body's destruction of its own cells, often overlooked or misdiagnosed by medical professionals. While it is closely linked with autoimmune gastritis, they are not interchangeable terms. Pernicious anaemia usually arises in the advanced stages of autoimmune gastritis, resulting in a deficiency of gastric intrinsic factor and subsequently causing vitamin B12 (cobalamin) deficiency.¹

Pernicious anaemia is complex due to cobalamin deficiency, causing issues from impaired blood cell production to neurological and psychiatric problems. Its cause is likely autoimmune, with T lymphocytes attacking gastric glands in susceptible people. Prior infection with Helicobacter pylori may trigger gastric autoimmunity, although this link has not been definitively established.¹

Research shows that pernicious anaemia impacts 0.1% of the general population and 2-3% of individuals over 65 years old. While it can affect people of any age, its occurrence tends to rise with age. Typically, it takes 10-12 years to show symptoms of pernicious anaemia, often beginning with hidden vitamin B12 deficiency. As a result, the true occurrence of pernicious anaemia diagnoses and associated complications may be underestimated due to its asymptomatic development.¹

Pernicious anaemia can cause severe long-term issues such as micronutrient deficiencies and the development of gastric cancer and type 1 gastric neuroendocrine tumours. Delayed recognition or diagnosis of pernicious anaemia can lead to life-threatening and sometimes irreversible complications.¹

Patients with pernicious anaemia typically experience a gradual onset of symptoms such as:²

• Paleness
• Fatigue
• Dizziness
• Rapid heartbeat
• Difficulty concentrating
• Diarrhoea
• Weight loss
• Anorexia
• Glossitis
• Dyspepsia
• Epigastric discomfort
• Postprandial bloating and fullness

Your doctor will order a series of tests to diagnose pernicious anaemia, such as:³

• Complete blood cell count (CBC)
• Peripheral blood smear
• Indirect bilirubin
• Lactate dehydrogenase
• Evaluation of gastric secretions
• Serum cobalamin
• Folic acid
• Methylmalonic acid
• Homocysteine 

The Schilling test, although no longer widely available, was traditionally part of the diagnostic process. Additionally, your doctor might suggest a clinical trial of vitamin B12, along with bone marrow aspiration and biopsy if necessary.³

Because prompt treatment significantly improves patient outcomes and prevents complications, the next section will provide detailed information on managing pernicious anaemia. Keep reading for valuable insights!

Essential goals for pernicious anaemia care

Your doctor will focus on several key goals when managing pernicious anaemia:³

• Confirming that you have a cobalamin deficiency
• If there's evidence of folic acid deficiency but pernicious anaemia hasn't been ruled out, your doctor will administer both folic acid and cobalamin until pernicious anaemia is excluded. Folic acid can restore blood counts but won't prevent neurological complications in pernicious anaemia
• Your doctor will investigate the cause of cobalamin malabsorption, although this may not always be pursued due to cost and complexity
• Administering sufficient cobalamin therapy
• Confirming the diagnosis by documenting the effectiveness of specific therapy
• Ensuring that you receive sufficient cobalamin throughout your life

Once therapy is started, hospitalisation is necessary only for patients with severe life-threatening anaemia. It may be needed until patients achieve an adequate hematologic response.³

Cobalamin therapy

Vitamin B12 can be used therapeutically through injection, as either cyanocobalamin or hydroxocobalamin. Both forms are equally useful in treating vitamin B12 deficiency and are generally safe, although rare allergic reactions may occur. Hydroxocobalamin may have some theoretical advantages, as it's better retained in the body and more readily available to cells, but both forms offer quick correction of cobalamin deficiency. Cobalamin comes in doses ranging from 100 to 1000 microgrammes. When doses exceed 50 microgrammes, most of it is quickly eliminated through urine. Therefore, for therapy initiation, repeated doses are advised to restore body stores.³

The recommended treatment for pernicious anaemia varies in dosage and administration of vitamin B12 replacement therapy.² It typically involves an initial phase of daily or every other day intramuscular injections of 1000 microgrammes of vitamin B12 (hydroxocobalamin in Europe or cyanocobalamin in the United States) for 1-2 weeks, followed by weekly injections for 1-2 months and then a monthly injection (cyanocobalamin) or every 2-3 months (hydroxocobalamin) thereafter for lifelong management.⁴

After the initial intensive treatment phase, patients with pernicious anaemia can choose between continuing intramuscular injections or switching to high-dose oral B12 supplements for lifelong maintenance. A study found that oral vitamin B12 is as effective as vitamin B12 intramuscular injection. High-dose cyanocobalamin (1000-2000 microgrammes) is typically taken daily as a tablet, though sublingual and intranasal forms exist but are not commonly recommended.⁴

The oral route may be necessary in the rare patients who have allergic reactions to injections, or in patients receiving anticoagulant or antiplatelet therapy. If this route is used, obtain blood cobalamin measurements at regular intervals to ensure that adequate quantities of cobalamin have been absorbed. Oral cobalamin therapy should be avoided in patients with neurologic symptoms including acute combined system degeneration, peripheral neuropathy, and psychosis.³

Dietary approaches and activity limitations

Strict vegetarians, especially those who avoid eggs, milk, and meat, may develop cobalamin deficiency. They should consider altering their diet or taking vitamin B12 supplements regularly. A weekly oral tablet of 100-200 microgrammes should provide adequate therapy. Patients with severe anaemia should limit strenuous physical activity until they respond well to treatment.³

Treatment response and follow-up

The first indication of treatment effectiveness manifests as a rise in reticulocyte count, often within 3 days of treatment initiation. Within the initial 5 days, there is a notable decrease of biochemical markers like methylmalonic acid and plasma homocysteine levels. Consistent normalisation of blood cobalamin levels usually occurs after 2 weeks of therapy.²

Macrocytosis is corrected during the initial month of treatment. It's crucial to monitor the patients regularly to spot any potential long-term effects of pernicious anaemia early on. A yearly clinical interview should be done to spot any new symptoms such as epigastric pain, dysphagia, or others, which may require further investigation. Consistent follow-up is essential for effective management.²

A consultation with a neurologist may be desirable in patients presenting with unusual neurological symptoms, particularly if macrocytic megaloblastic anaemia is absent. Patients with pernicious anaemia need regular outpatient follow-up to confirm their response to cobalamin therapy and ensure they receive it consistently throughout their lives.³

FAQ's

What is the best treatment for pernicious anaemia?

The recommended treatment for pernicious anaemia varies in dosage and administration of vitamin B12 replacement therapy.² It typically involves an initial phase of daily or every other day intramuscular injections of 1000 microgrammes of vitamin B12 (hydroxocobalamin in Europe or cyanocobalamin in the United States) for 1-2 weeks, followed by weekly injections for 1-2 months, and then a monthly injection (cyanocobalamin) or every 2-3 months (hydroxocobalamin) thereafter for lifelong management.⁴

Can you take oral B12 for pernicious anaemia?

After the initial intensive treatment phase, patients with pernicious anaemia can choose between continuing intramuscular injections or switching to high-dose oral B12 supplements for lifelong maintenance. A study found that oral vitamin B12 is as effective as vitamin B12 intramuscular injection. High-dose cyanocobalamin (1000-2000 microgrammes) is typically taken daily as a tablet, though sublingual and intranasal forms exist but are not commonly recommended.⁴

Summary

Pernicious anaemia is a condition where the body destroys its own cells, often related to autoimmune gastritis. It leads to a deficiency in gastric intrinsic factor, causing vitamin B12 deficiency. Symptoms include fatigue, dizziness, rapid heartbeat, and neurological issues. Diagnosis involves various tests, and treatment typically includes vitamin B12 replacement therapy, either through injections or oral supplements.

Dietary adjustments may be necessary, especially for strict vegetarians. Regular follow-up is crucial to monitor treatment effectiveness and address any complications. Early diagnosis and management are essential to prevent severe long-term complications.