1. Why do we get " Megaloblasts" in Megaloblastic anaemia?
2. Why we get anaemia in Megaloblastic anaemia?
Megaloblastic anaemia is called so due to presence of " Megaloblasts" in bone marrow.
What are " Megaloblasts" They're gigantic, abnormally BIG RBC-precursors seen in bone marrow. WHY do we see them ?
It needs some conceptual understanding.
Normally, RBC-precursors are big cells which divide rapidly as they mature & become progressively smaller as they divide while maturing towards mature-form of RBCs. Now, the problem begins in Megaloblastic anaemia that this cell-division is impaired due to lack of nutrients ( Folate & Vitamin B12). Vit B12 & Folate are critical for normal DNA synthesis & cell maturation. It's also described by a complex -term called " Nuclear-Cytoplasmic Asynchrony".
As DNA-synthesis is impaired, nuclear maturation of RBC-precursors get slowed up & could not match with the pace of cytoplasmic maturity/development. This DEFECTIVE NUCLEAR MATURATION halts cell-division & those big "MEGA" RBC-precursors remain as Big, MEGA, gigantic " Megaloblasts" in bone marrow giving the name as " Megaloblastic anaemia". Moreover, these " Megaloblasts" do NOT mature enough to get released into the peripheral blood & most RBC-precursors undergo " apoptosis " or apoptotic-death in bone marrow ..this causes anaemia in Megaloblastic anaemia.
Hope this helps some of you to understand the basic concepts.
-Md Mobarak Hussain (Maahii)
Beautifully explained !!
ReplyDelete