L10 - Nutritional Anaemias

Question 1

What is Anaemia?

Answer 1

It is a condition in which the number of red blood cells (and consequently their oxygen-carrying capacity) is insufficient to meet the body’s physiological needs.

Question 2

What is required in normal Erythropoeisis?

Answer 2

• vitamin B12 and folic acid (for DNA synthesis)
• Iron (haemoglobin synthesis)
• vitamins and cytokines
• healthy bone marrow environment

Question 3

What are 3 mechanisms of action of Anaemia?

Answer 3

• failure of production (hypoproliferation reticulocytopenic)
• ineffective Erythropoeisis
• decreased survival (blood loss, haemolysis, reticulocytosis)

Question 4

What is MCV and what can it tell you in terms of Anaemia?

Answer 4

Main cell volume

MICROCYTIC - small: dues to iron deficiency, thalassaemia (globin deficiency), anaemia of chronic disease

NORMOCYTIC - normal:
due to Aplastic anaemia, chronic renal failure, bone marrow infiltration, sickle cell disease.

MACROCYTIC - big: due to B12 deficiency, Folate deficiency, myelodysplasia, alcohol induced, drug induced, liver disease, myxoedema

Question 5

What is nutritional Anaemia?

Answer 5

Anaemia caused by lack of essential ingredients that the body aqquires from food sources.
iron,B12,folate

Question 6

Describe the distribution of Iron in adults?

Answer 6

dietary iron comes in and 1-2mg is absorbed at the duodenum.
A protein called plasma transferrin transfers the iron to where it is needed
Most of the Iron sits in the red blood cells, and then in the bone marrow.
Some iron in muscle (myoglobin) and in the liver.
Natural ways of losing iron - loss of cells in GI tract, Menstruation

Question 7

What are the stable forms of Iron

Answer 7

• ferric states (3+)

- Ferrous states (2+)

Question 8

How is Iron absorption regulated?

Answer 8

by GI mucosal cells and hepcidin, which regulated ferroprtin receptors on enterocytes of the duodenum and jejunum.
amount absorbed depends on type ingested

Question 9

What is Hepcidin and how does it regulate Iron?

Answer 9

It is a hormone that works via negative feedback. More hepcidin causes ferroportin internalistaion and degradation, thereby decreasing Iron transfer into the blood plasma from the duodenum.
Hepcidin is feedback regulated by iron concentrations in plasma, liver, and by erythropoeitic demand for iron.

Question 10

What are the 2 causes of iron deficiency and give examples?

Answer 10

NOT ENOUGH IN:
poor diet
malabsorption
increased physiological needs

LOSING TOO MUCH:
Blood loss
menstruation
GI Tract loss
parasites

Question 11

What are the 2 types of Macrocytic anaemia?

Answer 11

Megaloblastic - low reticulocyte count, vitamin b12/folic acid deficiency

Nonmegaloblastic - alcoholism, hypothyroidism, liver disease