Questions and Answers
What is the primary cause of megaloblastic anemia due to vitamin B12 deficiency?
Impaired synthesis of DNA
What is the term for the autoimmune attack on the gastric mucosa leading to atrophy of the stomach?
Pernicious anemia
What is the characteristic feature of the tongue in megaloblastic anemia?
Glossitis
What is the reason for the mild symptoms of malabsorption in megaloblastic anemia?
Signup and view all the answers
What is the shape of the macrocytes in megaloblastic anemia?
Signup and view all the answers
What is the characteristic feature of the neutrophils in megaloblastic anemia?
Signup and view all the answers
What is the characteristic feature of the bone marrow in megaloblastic anemia?
Signup and view all the answers
What is the significance of the presence of parietal cell antibody in the serum?
Signup and view all the answers
Study Notes
Megaloblastic Anemia
- Definition: Impaired DNA synthesis leading to macrocytic anemia, caused by deficiency of vitamin B12, folic acid, congenital enzyme defect, or acquired DNA defect synthesis.
Causes of Megaloblastic Anemia
- Vitamin B12 deficiency
- Folic acid deficiency
- Congenital enzyme defect
- Acquired DNA defect synthesis (e.g., hydroxyurea)
Pernicious Anemia
- Caused by autoimmune attack on gastric mucosa leading to atrophy of the stomach
- Characterized by achlorhydria and absence of intrinsic factor (IF) secretion
- More common in females (1.6:1 ratio) with peak occurrence at 60 years
- Associated with autoimmune diseases, including autoimmune polyendocrine syndrome
- Increased incidence of stomach carcinoma
- 90% of patients have parietal cell antibody in serum
- 35% of patients have a second antibody to IF that inhibits its ileal binding site
Clinical Features of Megaloblastic Anemia
- Mild jaundice (lemon-yellow tint) due to increased ineffective erythropoiesis in the bone marrow
- Glossitis (beefy-red sore tongue) and angular stomatitis due to epithelial abnormality
- Mild symptoms of malabsorption with weight loss
- Purpura due to thrombocytopenia
Laboratory Findings
- Macrocytic anemia (MCV > 98 fL) with oval-shaped macrocytes
- Low reticulocyte count
- Moderately reduced total white cell and platelet counts, especially in severely anemic patients
- Hypersegmented neutrophils (with six or more lobes) in a proportion of patients
- Hypercellular bone marrow with large erythroblasts showing failure of nuclear maturation
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
