Anaemia, B12, Folate and polycythaemia

Question 1

Define anaemia

Answer 1

Decreased concentration of Hb in blood

Question 2

Symptoms of anaemia? 7

Answer 2

fatigue
dyspnoea
palpitations
headache
pallor
tachyardia
systolic murmur

Question 3

Why do anaemias develop (in general)?

Mechanisms. Bone marrow, peripheral tissue, removal

Answer 3

Bone marrow- Abnormal erythropoesis or abnormal Hb Synthesis
Peripheral red blood cells- Abnormal function, structure or metabolism
You can get excessive blood loss
Removal- Abnormal function of RES

Question 4

3 reasons why you may get abnormal erythropoesis?

Answer 4

Bone marrow exposure to chemicals, ionising radiation, infection

Question 5

Define aplastic anaemia?

Answer 5

Inability for haematopoeitic stem cells to make mature blood cells

Question 6

How can chronic kidney disease lead to decrease erythropoesis?

Answer 6

Less Erythropoetin secreted

Question 7

5 causes of iron deficiency?

Answer 7

blood loss
increased requirement for iron (pregnancy, growth spurt)
decreased dietary supply or absorption (eg in coeliac disease)
Anaemia od chronic disease–>decreased function iron

Question 8

What is anaemia of chronic disease?

Answer 8

Associated with chronic inflammation
increased activity of macrophages–>decreased lifespan of red blood cells and signalling through erythopoetin receptor is blunted–>anaemia

Also you get a chronic release of heparin–>decreased absorption of iron

Question 9

What is thalassemia?

Answer 9

decreased or absent alpha or β globin chain production

leads to increased haemolysis

Question 10

Mechanics of sickle cell disease?

Answer 10

Glutamate–>valine
you get a sticky hydrophobic pocket so red blood cells clump togeether
sickle chaped, prone to lyse–>increased haemolysis

Question 11

What type of anaemia do you get with folate and b12 deficiency and why?

Answer 11

Megaloblastic anaemia
Inability of red blood cell precursors to synthesise DNA and divide
so you get large partially replicated red blood cells

Question 12

Name two deficiencies is red blood cell metabolism

Answer 12

G6PDH deficiency

Pyruvate kinase deficiency

Question 13

Describe G6PDH deficiency and why you get anaemia

Answer 13

Decreased pentose phosphate pathway–> decreased NADPH
NADPH is used in in the glutathione reaction
GSSG–>GSH
Cannot be recovered, so leads to increased damage from oxidative stress
leads to increase haemolysis

Question 14

What can G6PDH deficiency lead to and why?

Answer 14

Jaundice, because increased no. of red blooc cells are being destroyed so increased concentration of bilirubin

Question 15

Describe the glutathione path to protecting us from oxidative stress?

Answer 15

glutathione donates an electron to a ROS
in the process becomes GSSG
the enzyme that catalyses this reaction is glutathione peroxidase
then GSSG–>GSH using glutathione reductase
NADPH–>NADP+ in the process

Question 16

Describe pyruvate kinase deficiency and how it can lead to anaemia

Answer 16

deficient in pyruvate kinase
less phosphoenol pyruvate–>pyruvate
in the process, ADP–>ATP
so less ATP production
means the Na+/K+ ATPase cannot work as well
so concentration of K+ decreases
cell shrinkage–>cell death–>haemolytic anaemia

Question 17

Define myeloproliferative disorder

Answer 17

disease of the bone marrow–>increased no of cells

Question 18

Defin polycytheria

Answer 18

when the volume percentage of erythrocytes is greater than 55%

Question 19

Can causes polycytheria vera?

Answer 19

myeloproliferative neoplasm in the bone marrow

Question 20

What does polycytheria vera result in?

Answer 20

thicker blood–>thombosis, haemorrhage, burning pain in the extremities, splenomegaly

Question 21

what is the treatment for polycytheria vera?

Answer 21

phlebotomy