Red cells 1 - congenital anaemias

Question 1

What is anaemia?

Answer 1

reduction in red cells or Hb content

Question 2

Main substances required for RBC synthesis

Answer 2

erythropoietin
Vit B 12 and folic acid
iron

Question 3

life span of RBC

Answer 3

120 days

Question 4

reticuloendothelial system

Answer 4

macropahges in spleen, liver, lung, LN etc

Question 5

recycling of RBC

Answer 5

globin - amino acids

haem - iron and bilirubin

Question 6

unconjugated bilirubin

Answer 6

bound to albumin in plasma

Question 7

3 areas of problems in congenital anaemias of RBC

Answer 7

membrane
enzymes
haemoglobin

Question 8

red cell membrane

Answer 8

skeletal proteins keep shape and deformity

Question 9

red cell membrane proteins

Answer 9

ankyrin
beta and alpha spectrin
band 3

Question 10

inheritance of hereditary spherocytosis

Answer 10

autosomal dominant

Question 11

RBC in hereditary spherocytosis

Answer 11

defects in membrane proteins

RBC are spherical and removed by RE system

Question 12

Clinical presentation of hereditary spherocytosis

Answer 12

anaemia
jaundice (neonatal)
pigment gallstones
splenomegaly

Question 13

Treatment of hereditary spherocytosis

Answer 13

folic acid
transfusion
splenectomy

Question 14

G6P-D

Answer 14

enzyme protecting from oxidative stress

NADPH reduce glutathione, detoxifies oxygen species

Question 15

What does G6P-D deficiency confer an advantage for?

Answer 15

malaria

Question 16

G6P-D deficiency inheritance

Answer 16

x-linked

affect males and female carriers

Question 17

G6P-D deficiency blood film

Answer 17

blister and bite cells

Question 18

clinical presentation of G6P-D deficiency

Answer 18

neonatal jaundice
Drugs, beans,infection precipitated
splenomegaly
pigment gallstones

Question 19

precipitants of G6P-D deficiency

Answer 19

drugs eg anti-malarials,anti-bacterials

fava beans

Question 20

structure of haemoglobin

Answer 20

iron containing haem with 4 globin chains - 2 alpha and 2 beta

Question 21

haemoglobin oxygen binding

Answer 21

oxyhaemoglobin - relaxed binding

deoxyhaemoglobin - tight binding : 2,3-DPG

Question 22

Oxygen dissociative curve

Answer 22

hyperthermia
acidosis
hypercapnia

Question 23

HbA or HbF higher O2 affinity?

Answer 23

HbF

Question 24

alpha and beta chains - how many genes?

Answer 24

2 alpha chains - 4 alpha genes

2 beta chains - 2 beta genes

Question 25

Thalassaemia underlying problem

Answer 25

reduced or absent globin chain production

Question 26

sickle cell underlying problem

Answer 26

severely abnormal globin chain

Question 27

sickle cell inheritance

Answer 27

autosomal recessive | 1 in 4 affected, 1 in 2 carrier

Question 28

Defomity of sickle cell

Answer 28

haem + 2 alpha chains + 2 beta (sickle chains) | point mutation in beta chain

Question 29

Consequences of sickle cell

Answer 29

haemolysis due to red cell injury inflammation, vasomotor tone, endothelial activation VASO-OCCLUSION

Question 30

Clinical presentation of sickle cell

Answer 30

``` painful vaso-occlusive crisis (bone) stroke chest crisis increased infection due to hyposplenism sequestration crisis - spleen, liver chronic haemolytic anaemia ```

Question 31

life expectancy with sickle cell

Answer 31

M=42, female = 48 | due to child and perinatal mortality

Question 32

Painful crisis treatment

Answer 32

opiates oxygen hydration ?antibiotic

Question 33

chest crisis symptoms

Answer 33

increasing hypoxia, chest pain, fever, infiltrates on CXR

Question 34

chest crisis treatment

Answer 34

``` resp support antibiotics IV fluids analgesia transfusion ```

Question 35

life long prophylaxis for sickle cell

Answer 35

vaccination, penicillin (+malaria), folic acid

Question 36

acute events management for sickle cell

Answer 36

hydration, oxygen, infection, analgesia

Question 37

Other treatments for sickle cell

Answer 37

transfusion disease modifying drugs - hydroxycarbamide bone marrow transplant and gene therapy

Question 38

4 types of thalassaemia

Answer 38

homozygous alpha zero - incompatible with life beta thalassaemia major - life long transfusion non transfusion dependent thalassaemia minor

Question 39

Thalassaemia symptoms

Answer 39

severe anaemia:3-6months old expansion of ineffective bone marrow - hair on end splenomegaly growth retardation

Question 40

Treating thalassaemia

Answer 40

chronic transfusion support (4-6weekly) avoid iron overload - chelation curative bone marrow transplant

Question 41

outcome of iron overload

Answer 41

heart, endocrine, liver failure