Pernicious anemia:

Pathophysiology of pernicious anemia and it’s treatment.

Meaning of Pernicious is very dangerous or harmful. The pernicious anemia also known as Addison’s anaemia occurs because of deficiency of hemoglobin in the red blood cells. Deficiency of hemoglobin is caused by deficiency of Vitamin B12. Vitamin B12 is responsible for formation of cell walls and protein synthesis. Deficiency of vitamin B12 forms a thinner walls of RBC and oversized bigger size red blood cells which gets ruptured and distroyed while passing through spleen causing anemic condition. The red blood cells formed are in larger size because of incomplete protein synthesis.The red blood cells formed are immature megaloblasts and are fragile. Often the RBC count is reduced due to RBC lysis of megaloblastic RBCs while passing through spleen.

Reduction in the red blood cells while passing through spleen and self lysis due to immature red blood cells.Which further causes deficiency of red blood cells and hemoglobin.Which ultimately results in anemia, this is called pernicious anemia.

Vitamin B12 source and absorption in blood:

Vitamin B12 is available in food and is released in the gastrointestinal tract. An intrinsic factor is responsible for binding vitamin B12 and carrying it to intestinal cells. And further transportation of vitamin B12 inside the blood vessels, from there it is absorbed into the cells and utilised for production of amino acids. Amino acids which are backbone of protein.

In case of deficiency of intrinsic factor (IF) Vitamin B12 can not be absorbed into the blood from gut.Deficiency of vitamin B12 occurs due to the deficiency of intrinsic factor.

Improper digestion of food also results in deficiency of vitamin B12. Achlorhydria deficiency of hydrochloric acid, due to lack of parietal cells in the stomach which produce HCL in the stomach. Insufficient PH in the GIT is also responsible for incomplete digestion and incomplete release of Vitamin B12 from food for absorption. False positive Pap smear is observed in case of women with long term vitamin B12 deficiency.

Causes of Pernicious anemia:

Damage to Gastric lining: Damage to gastric lining due to various factors like cancer or side effects of medicines. Atrophic gastritis.

Gastric bypass surgery : Pernicious anemia is often observed in patients with Gastric bypass surgery

Autoimmune Disorder: Autoimmune Atrophic gastritis, Immune system attack the parietal cells which produce intrinsic factor and Hydrochloric acid. Auto antigenic effect due to cross antigenicity.

Family history: If any one from family had pernicious anemia, there is risk of the disease may occur

Treatment of Pernicious anemia:

Due to the damaged gastric track, oral Vitamin B12 doesn’t get absorbed in the blood. Also if Intrinsic factor is deficient, the oral Vitamin B12 therapy doesn’t work in pernicious anemia. Therefore intramuscular Vitamin B12 injection is given till blood Vitamin B12 level is attained. Some patients are given daily doses of oral vitamins containing Vitamin B12, it may work depending on the condition of the patient.

Also along with Vitamin B12 and folic acid is also given to patient. Folic acid and vitamin B12 play role in protein of blood cell wall and hemoglobin biosynthesis.