Megaloblastic Anemia

Megaloblastic Anemia Introduction

• Megaloblastic anemia is a type of anemia characterized by the presence of large, abnormal red blood cells (megaloblasts) in the bone marrow and peripheral blood.
• It is primarily caused by deficiencies in vitamin B12 or folic acid, both essential for DNA synthesis.

Causes of Megaloblastic Anemia:

Vitamin B12 Deficiency

1. Dietary Deficiency: Insufficient intake of animal products (common in vegans).
2. Malabsorption:
   • Pernicious Anemia: Autoimmune destruction of stomach cells producing intrinsic factor.
   • Surgical Removal: Parts of the stomach or intestines removed surgically.
   • Gastrointestinal Diseases: Conditions like Crohn’s disease.
3. Other Causes:
   • Chronic Alcoholism
   • Certain Medications: Such as metformin and proton pump inhibitors.

Folic Acid Deficiency

1. Dietary Deficiency: Poor intake of folate-rich foods (leafy greens, fruits, nuts, beans).
2. Increased Demand:
   • Pregnancy and Lactation
   • Rapid Cell Turnover: Conditions like hemolytic anemia and cancer.
3. Malabsorption: Conditions like celiac disease or surgical removal of parts of the intestines.
4. Other Causes:
   • Chronic Alcoholism
   • Certain Medications: Such as methotrexate and anticonvulsants.

Pathophysiology

• Disrupted DNA Synthesis: Deficiencies in vitamin B12 or folic acid disrupt DNA synthesis.
• Production of Megaloblasts: Leads to the formation of large, immature red blood cells (megaloblasts).
• Impaired Cell Division: These abnormal cells have an impaired ability to divide and mature properly.
• Ineffective Hematopoiesis: Results in anemia and decreased production of functional blood cells.

Symptoms of Megaloblastic Anemia:

• Common symptoms of megaloblastic anemia include:

1. Fatigue and Weakness
2. Shortness of Breath
3. Pale or Jaundiced Skin
4. Glossitis: Inflamed, sore tongue.
5. Neurological Symptoms (specific to vitamin B12 deficiency):
   • Numbness and tingling in hands and feet.
   • Balance problems.
   • Cognitive disturbances.
6. Gastrointestinal Symptoms:
   • Loss of appetite.
   • Weight loss.
   • Diarrhea

Diagnosis

• Diagnosis typically involves:

1. Complete Blood Count (CBC): Low hemoglobin, high mean corpuscular volume (MCV).
2. Serum Vitamin B12 and Folate Levels: Low levels indicate deficiency.
3. Peripheral Blood Smear: Presence of large, oval-shaped RBCs (macrocytes) and hypersegmented neutrophils.
4. Bone Marrow Examination: Megaloblastic changes in bone marrow cells.
5. Methylmalonic Acid and Homocysteine Levels: Elevated in vitamin B12 deficiency.

Treatment

Vitamin B12 Deficiency

1. Dietary Changes: Increase intake of vitamin B12-rich foods (meat, fish, dairy products, fortified cereals).
2. Vitamin B12 Supplements:
   • Oral Supplements
   • Intramuscular Injections: For individuals with absorption issues.
3. Treat Underlying Causes: Address gastrointestinal conditions or dietary deficiencies.

Folic Acid Deficiency

1. Dietary Changes: Increase intake of folate-rich foods (leafy greens, fruits, nuts, beans).
2. Folic Acid Supplements: Oral supplementation.
3. Treat Underlying Causes: Address malabsorption issues or conditions with increased demand.

Thank you for reading from Firsthope's notes, don't forget to check YouTube videos!