Difference Between Megaloblastic and Pernicious Anemia

The key difference between megaloblastic and pernicious anemia is that megaloblastic anemia is a type of anemia in which red blood cells are larger than the normal size while pernicious anemia is a type of megaloblastic anemia that happens due to deficiency of vitamin B12.

Red blood cells (RBC) are the most common type of blood cells. RBCs deliver oxygen to body tissues. Anemia is a condition which refers to the low capacity of red blood cells to transport enough oxygen to body tissues or low concentration of haemoglobin in red blood cells. It is a result of several factors including inadequate RBC production, excessive RBC destruction, abnormality of red blood cells or blood loss. Megaloblastic anemia is a type of anemia condition. Pernicious anemia is a type of megaloblastic anemia caused by vitamin B12 deficiency. Body tissues and organs do not get enough oxygen due to megaloblastic anemia.

CONTENTS

1. Overview and Key Difference
2. What is Megaloblastic Anemia
3. What is Pernicious Anemia
4. Similarities Between Megaloblastic and Pernicious Anemia
5. Side by Side Comparison – Megaloblastic vs Pernicious Anemia in Tabular Form
6. Summary

What is Megaloblastic Anemia?

Megaloblastic anemia is a type of anemia condition which is characterized by the presence of large red blood cell precursors called megaloblasts in the bone marrow. In this condition, red blood cells are larger than normal red blood cells. There is also a low number of red blood cells in the circulation. Megaloblastic anemia arises due to impaired DNA synthesis leading to inhibition of nuclear division.

There are two main causes of megaloblastic anemia. They are vitamin B12 deficiency and folate deficiency. Megaloblastic anemia caused by vitamin B-12 deficiency is referred to as pernicious anemia. Moreover, folate is needed for the development of healthy red blood cells. Therefore, vitamin B12 and folate deficiency are the most common causes of megaloblastic anemia.

What is Pernicious Anemia?

Pernicious anemia is a blood disease that happens due to the insufficient uptake of vitamin B12. In pernicious anemia condition, large, immature, nucleated red blood cells circulate in the blood. The uptake of vitamin B12 decreases when the body lacks an intrinsic factor in the gastric mucosa since intrinsic factor facilitates the absorption of dietary vitamin B12 in the small intestine. Vitamin B12 is needed for hemoglobin production. In other words, vitamin B12 aids the body to produce healthy red blood cells. Therefore, pernicious anemia is a type of vitamin B12 deficiency anemia. The major cause of pernicious anemia is the loss of stomach cells that produce intrinsic factor.

The symptoms of pernicious anemia are fatigue, weakness, headache, chest pain, weight loss and pale skin. As a result of pernicious anemia, nerves and other organs can be permanently damaged. There is also a risk of developing stomach cancer. Vitamin B12 pills and diet changes are two types of treatments of pernicious anemia.

What are the Similarities Between Megaloblastic and Pernicious Anemia?

• Pernicious anemia is a type of megaloblastic anemia.
• Deficiency of vitamin B12 is responsible for both megaloblastic and pernicious anemia.
• Due to both diseases, body tissues and organs don’t get enough oxygen.

What is the Difference Between Megaloblastic and Pernicious Anemia?

Megaloblastic anemia is a type of blood disease in which bone marrow produces unusually larger red blood cells than the normal. Most common causes of megaloblastic anemia are vitamin b12 and folate deficiencies. Pernicious anemia is a type of megaloblastic anemia which is caused by vitamin B-12 deficiency. So, this is the key difference between megaloblastic and pernicious anemia. As a result of megaloblastic anemia, body tissues and organs do not get enough oxygen.

Below is a summary of the difference between megaloblastic and pernicious anemia.

Summary – Megaloblastic vs Pernicious Anemia

Megaloblastic anemia is a condition in which the bone marrow produces unusually large, structurally abnormal, immature red blood cells. It happens due to the impaired DNA synthesis leading to inhibition of nuclear division. Major causes are vitamin B12 and folate deficiencies. Pernicious anemia is a type of megaloblastic anemia in which our body fails to produce enough red blood cells due to the deficiency of vitamin B12. It is a result of the lack of intrinsic factor. Thus, this is the summary of the difference between megaloblastic and pernicious anemia.

Reference:

1. Hariz, Anis, and Priyanka Bhattacharya. “Megaloblastic Anemia”. Ncbi.Nlm.Nih.Gov, 2020, Available here.
2. “Pernicious Anemia | National Heart, Lung, And Blood Institute (NHLBI)”. Nhlbi.Nih.Gov, 2020, Available here.

Image Courtesy:

1. “Hypersegmented neutrophil” By Paul Weisz Carrington, M.D (Public Domain) via Commons Wikimedia
2. “Metaplastic atrophic gastritis – body – chromogranin A — intermed mag” By Nephron – Own work (CC BY-SA 4.0) via Commons Wikimedia