Pernicious Anemia

1. Diagnostic Tests

1.1. Bone marrow biopsy

1.1.1. Megalobastic red blood cell precursors and giant metamyelocyctes

1.2. Blood tests

1.2.1. Antibodies

1.3. Gastric biopsy

1.3.1. Structure of stomach lining and test for H. Pylori

1.4. Schillings test

1.4.1. Old test used to evaluate Vit. B12 absorption by using radioactive B12.

1.5. Serologic tests

1.5.1. Measuring methylmalonic acid and homocysteine levels

2. Pathophysiologic Etiology

2.1. Immune

2.1.1. Immune gastritis

2.1.2. Lacking intrinsic factor

2.2. Inflammation

2.2.1. Inflammation causes parietal cell damage

2.3. Most common megalobastic anemia

3. References

3.1. McCance, K. L., & Huether, S. E. (2014). Pathophysiology: the biologic basis for disease in adults and children (7th ed.). St. Louis,, MO: Elsevier.

3.2. Patient education: Pernicious anemia (The Basics). (2018). UpToDate. Retrieved April 17, 2018, from UpToDate anemia&source=search_result&selectedTitle=4~92&usage_type=default&display_rank=4#H14571537.

4. Treatment

4.1. Identify cause

4.2. Vitamin B12 supplements

4.2.1. B12 injections: Every day for 1 week, One shot per week for 4 weeks, then monthly shots for life.

5. Causative Factors

5.1. Autoimmune disorder

5.1.1. Type A Gastritis

5.2. Gastric submucosa becomes inflamed damaging parietal and zymogenic cells

5.3. Partial stomach removal

6. Risk Factors

6.1. Genetic predisposition

6.2. Excessive alcohol, smoking, and hot tea ingestion.

6.3. Proton pump inhibitors

6.4. Northern European Descent

6.4.1. Scandinavian, English, and Irish

7. Common Findings

7.1. Symptoms appear after age 30. Median diagnosis age 60.

7.2. EARLY: Infections, mood swings, and gastrointestinal, cardiac, and kidney ailments. Elevated methylmalonic acid and homocysteine levels

7.3. LATE: Hemoglobin <7, nerve demyelination, lemon colored skin.

7.4. Vitamin B12 Deficiency

7.5. Generalized symptoms: Pale skin, lethargic, headaches, muscle pain, trouble concentrating, and tingling of the skin.