Haemopoiesis, anaemia + haemolysis Flashcards

1
Q

Where does haematopoeisis occur in a fetus?

A

yolk sac then liver and spleen

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2
Q

Where does haematopoeisis occur in an adult?

A

bone marrow of the axial skeleton (skull, ribs, sternum, pelvis, prox femur)

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3
Q

Which cells develop from the lymphoid lineage?

A
  • lymphocytes: B cells, T cells, NK cells - dendrites
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4
Q

Which cells develop from the myeloid lineage?

A
  • granulocytes: neutrophils, basophils, eosinophils - platelets - erythrocytes - macrophages - dendritic cells - mast cells
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5
Q

Which myeloid cells target tissues?

A

macrophages mast cells dendritic cells

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6
Q

give the pathway for erythropoiesis

A

haemocytoblast proerythroblast early erythroblast late erythroblast reticulocyte mature erythrocyte

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7
Q

At what stage of erythropoeisis is/are a) the nucleus lost? b) ribosomes lost?

A

a) when reticulocyte is formed b) when mature erythrocyte is formed

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8
Q

How is erythopoeitin produced?

A

in kidneys cells have a signalling molecule called hypoxia-inducible factor which needs oxygen to be broken down in hypoxia this doesn’t happen so the signal is sent to increase production of erythopoeitin

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9
Q

Where are erythrocytes destroyed?

A

in the spleen by macrophages

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10
Q

What are the specialised antigens on rbc called?

A

agglutinatagens

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11
Q

In microcytic anaemia where is the problem?

A

the cytoplasm - impaired haemoglobin

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12
Q

In macrocytic anaemia where is the problem?

A

the nucleus - impaired cell division

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13
Q

Causes of microcytic anaemia

A

iron deficiency anaemia of chronic disease thalassaemia lead poisoning

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14
Q

How does lead poising affect blood results?

A

microcytic microchromic due to its effect on porphyrin ring synthesis

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15
Q

Causes of macrocytic anaemia

A

b12/folate deficiency drug-induced alcohol hypothyroid pregnancy

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16
Q

What is the most common cause of macrocytosis?

A

alcohol

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17
Q

Where does platelet production occur?

A

platelets bud off from megakaryocytes in the bone marrow

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18
Q

What do neutrophils do?

A

immediate line of defence

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19
Q

What do eosinophils do?

A

fight parasitic infections, involved in hypersensitiviy

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20
Q

What does a monocyte become in tissues?

A

macrophage

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21
Q

name the a) oxidised version b) reduced version of iron

A

a) Fe3+ = ferric (more positive because it has lost an electron and oxidation is loss) b) Fe2+ = ferrous

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22
Q

In red cell destruction what does a) globin b) heme become?

A

a) amino acids b) iron recycled, porphyrin becomes unconjugated bilirubin

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23
Q

Which pathway generates ATP and NADH? why?

A

Ebden-Meyerhof ATP needed for Na-K pump to maintain osmotic pressure NADH prevents Fe2+ oxidation

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24
Q

How do we prevent free radicals from damaging the erythrocyte?

A

hexose monophosphate shunt generates NADPH that maintains glutathione (an antioxidant capable of donating electrons)

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25
Which enzyme is the rate-limiting step in the pathway that prevents oxidative damage?
glucose-6-phosphate dehydrogenase (G6PD)
26
What chains make up a) fetal haemoglobin? b) adult haemoglobin?
a) 2 alpha, 2 gamma b) 2 alpha, 2 beta
27
Which effect moves the oxygen dissociation curve to the a) left? b) right?
a) Haldane b) Bohr
28
What is the Haldane effect?
decreased affinity for CO2 at the lungs results in CO2 release
29
What is the Bohr effect?
decreased affinity for oxygen at the tissues results in oxygen release
30
Which factors influence the Haldane effect?
increased pH decreased DPG decreased temperature
31
Which factors influence the Bohr effect?
CADET face right: inc CO2, acid, inc DPG, exercise inc temperature
32
Which protein measures a) iron supply? b) iron storage?
a) transferrin saturation b) ferritin
33
What is megaloblastic macrocytic anaemia?
Defect in the maturation of the nucleus means that their isn't enough division (cells aren't getting smaller) happening so the cell has the contents of more cells the cells might be larger but daughter cells apoptose more so there are fewer
34
What does reticulocytosis occur in response to ?
acute blood loss or haemolysis
35
In b12 absorption which protein a) binds in the stomach to stop it being destroyed by acid? b) binds in the duuodenum so it can be absorbed
a) r binder b) intrinsic factor
36
Where is b12 absorbed?
distal small bowel - ilium
37
What is the master iron regulator and how does it work?
hepcidin inhibits ferroportin
38
SE of oral iron supplements
Abdominal pain constipation bloating diarrhoea black stools
39
Why can B12 deficiency present with neurological symptoms?
may affect methyl donor on myelin sheath makes prone to present with neurological problems
40
What is pernicious anaemia?
auto-immune condition affecting gastric mucosa (intrinsic factor, parietal and gastric cells) causing vitamin B12 malabsorption associated with hypothyroid and other autoimmune conditions
41
How are haemoglobinopathies usually inherited?
autosomal recessive
42
What type of anaemia is seen in thalassaemia and why?
microcytic hypochromic anaemia problem with globin chains causes ineffective erythopoeisis and lots of red cells undergo apoptosis
43
What happpens if you lose 1 or 2 alpha chains?
A thal trait - no treatment if asymptomatic
44
What happens if you lose 3/4 alpha chains?
you have HbH disease as there is an excess of beta chains that form tetramers that cant carry oxygen may need transfusions
45
What happens if you have no working alpha chains?
Hb Barts hydrops fetalis (most severe) no adult hb usually incompatible with life
46
How does alpha thalassaemia come about?
1/2/3/4 of alpha genes knocked out
47
How does beta thalassaemia come about?
point mutations in the gene
48
how do we illustrate there being reduced beta synthesis and absent beta synthesis?
B+ = reduced B0 = absent
49
If one of the two beta genes is reduced or absent how will it present?
beta thalassaemia trait - asymptomatic - low MCV - normal Hb
50
if both the mother and father have beta thalassaemia trait what is the chance of beta thal major in the child?
1/4
51
What is beta thal intermedia?
2 x reduced 1x reduced, 1 x absent - moderate - occasional transfusions
52
What is beta thal major?
no beta chain synthesis - severe - life-long transfusions - extramedullary haematopoeisis --\> hepatosplenomegaly, skeletal changes, organ damage
53
What are sickling disorders?
a structural variant of haemoglobin which polymerises in low oxygen to distort the RBC and damage its membrane
54
How do we illustrate a) sickle trait? b) sickle cell anaemia?
a) HbAS b) HbSS
55
features of sickle cell anaemia
episodes of crisis in hypoxia, dehydration, infection... chronic haemolysis hyposplenism
56
How do you manage sickle cell anaemia?
avoid triggers of crisis opiates, fluids, rest, oxygen, antibiotics, transfusion if severe crisis folic acid and hydroxycarbamide if hyposplenic --\> prophylactic penicillin
57
First sign of haemolysis
jaundice
58
is haemolytic anaemia compensated ?
no rate of red cell destruction exceeds the bone marrow's capacity to make new cells
59
How can we detect haemolysis?
reticulocyte count breakdown products
60
In which type of haemolysis is there excess bilirubin?
extravascular: due to release of protoprophyrin
61
What products are seen in intravascular haemolysis?
abnormal process = abnormal products eg haemosiderin and haemoglobin in urine
62
Causes of intravascular haemolysis
* prosthetic heart valve * ABO incompatible transfusion reaction * G6PD deficiency * falciparum malaria * Paroxysmal nocturnal hemoglobinuria (PNH) * Thrombotic thrombocytopenic purpura * cold autoimmune haemolytic anaemia
63
Causes of extravascular haemolysis
* Delayed transfusion reaction * Warm autoimmune hemolytic anemia * Hereditary spherocytosis * Hypersplenism
64
Which type of AIHA is a) IgG? b) IgM?
a) warm b) cold
65
Which type of autoimmune haemolytic anaemia results in intravascular haemolysis?
cold
66
What does hypersegmented nuclei on a blood film indicate?
macrocytic vitamin B12/folate deficiency
67
When does reticulocytosis manifest after an acute bleed?
1-2 days
68
Is acute transfusion reaction IgG or IgM?
IgG
69
Causes of raised platelets (thrombocytosis)
primary - bone marrow problem secondary - trauma, surgery, splenectomy, active infection, iron deficiency, anaemia, malignancy (LEGO C lung endometrial GI oesophageal colorectal)
70
In a patient who is deficient in both b12 and folate, which do you replace first?
b12
71
How do patients on haemodialysis maintain adequate haemoglobin?
treatment with erythropoietin
72
What usually causes an aplastic crisis in sickle cell disease? How does it present?
parovirus B19 sudden fall in haemoglobin
73
aplastic crisis + symptoms
transfuse
74
risk factors for TTP
obesity pregnancy female african
75
What happens to ferritin levels in anaemia of chronic disease?
increased
76
When is TIBC increased?
iron-deficiency pregnancy
77
Which drugs can cause aplastic anaemia?
Phenytoin Chloramphenicol Cytotoxics Sulphonamides
78
Treat acute transfusion reaction
generous fluid resuscitation and termination of the transfusion
79
Acutely swollen and painful fingers is a sign of what disease?
dactylitis is a sign of sickle cell anaemia
80
Diagnose sickle cell anaemia
haemoglobin performance liquid chromatopgraphy
81
What blood results would you expect in vitamin D deficiency
* increase parathyroid hormone * low calcium * low phosphate * high ALP
82
Which diagnosis is most likely with the following blood results Low Hb, low white cells and low platelets ?
pancytopenia --\> aplastic anaemia
83
What causes sickle cell disease?
point mutation in the globin gene
84
92 year old woman who is breathless after receiving a 4 unit red cell transfusion for chronic anaemia.
Transfusion associated circulatory overload
85
48 year old man becoming breathlessness two hours after an infusion of fresh frozen plasma.
Transfusion related acute lung injury
86
Which pathway is the most common form of glycolysis?
Ebden-Meyerhoff
87
What is glutathione?
an antioxidant capable of donating electrons
88
Name a small molecule with high affinity for oxygen
2,3-BPG
89
gastric resection + peripheral neuropathy
B12 deficiency
90
Young female, spenomegaly, intermittent mild jaundice, gallstones and father had a splenectomy as a child
hereditary spherocytosis