Heamatology summray 5

Chapter 5 in Haemtology (Macrocytic Anaemia) summary

 

-Macrocytic anaemia show an increased size of circulating red cells (MCV>98 fl).Causes include vitamin B12 (B12,cobalamin) or folate deficiency,alcohol,liver disease, hypothyroidism,myelodysplasia, paraproteinneamia, and the neonatal period.

-B12 or folate deficiency cause megaloblastic anaemia, in which the bone marrow erythroblast  have a typical abnormal appearance.

-B12 deficiency is usually caused by B12 malabsorption brought about by pericious anaemia in which there is autoimmune gastric, resulting in severe deficiency of intrinsic factor, a glycoprotien made in stomach which faciliates B12 absorption by the ileum.

-Other gastrointestinal diseases as well as a vegan diet may cause B 12 deficiency .

-folate deficiency may be caused by a poor diet ,malabsorption (e.g.gluten-induced enteropathy)or excess cell turnover(e.g.pregnancy,haemolytic anaemias, malignancy)

-Treatment of B 12 deficiency is usually with injection of hydroxocobalamin and of folate deificency with oral folic (pteroyglutamic) acid.

-Rare cause of megaloblastic anaemia include inborne errors of B 12 or folate transport oe metabolism , and defects of DNA synthese not related toB12 or folate.

 

From book: Essentail Haematology A.V.HOFFBRAND,P.A.H.MOSS.6EDITION