We will now talk about another type of Granulocytes called Eosinophils.
Introduction
1) Eosinophil is one of rarest leukocytes found in the normal blood smear
2) Contained numerous pinkish or reddish-orange granules
3) Azurophilic granules also present
4) Bilobed nucleus, makes it looks like a sausage with nuclear projection linking the two lobes
Eosinophilic Granules
1) Numerous specific granules stained by Eosin dye – basic in nature
+Specific eosinophilic granules
-Crystalline core or internum containing large number of arginine
+These proteins function in killing parasitic worm especially shistosomes
-Surrounds the internum is the externum
+Azurophilic granules
-Contained lysosomal enzymes to digest parasitic worms
Clinical importance of Eosinophils
1) Eosinophil contains IgE, one type of immunoglobulin important for parasitic infection
2) Eosinophil DEACTIVATES inflammatory (anti-allergic reaction) activity by inactivating
+Histamine
+Leukotriene
3) It also phagocytoses antigen – antibody complex
4) Increased in number indicates parasitic infection
5) Corticosteroid tends to decrease its number
Formation of Eosinophil
Like neutrophil, eosinophil production is control by cytokine especially Colony Stimulating Factor (CSF). Below is the diagram
Pluripotent Heamopoeitic Stem Cell –> CFU-S –> CFU-Eosinophil –> Myeloblast –> Promyelocyte –> Eosinophil myelocyte –> Eosinophil metamyelocyte –> Stab cell –> Eosinophil
That is all about Eosinophil. Simple and easy, isn’t it? I hope so =)
Thank you guys =)
Virtual Medic 