Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Semester 4: Haematology > haemolytic anaemias > Flashcards

haemolytic anaemias Flashcards

1
Q

haemolytic anaemia

A

anaemia due to reduced RBC survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

describe the normal RBC lifestyle

A
  1. RBC production (Iron, B12/Folate, Globin chains, Protoporphyrins)
  2. RBCs circulate for 120 days
  3. Removal of old RBCs (membrane changes are detected by macrophages)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Normal Red blood cell

A
  1. biconcave disc shape
  2. haemoglobin (carries o2)
  3. Metabolic pathways (ensuring RBC maintains structure and function)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is haemolysis?

A

destruction of RBCs -> bone marrow compensates by increasing RBC production -> increased immature RBCs in the circulation (reticulecytosis, nucleated RBCs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

compensated haemolysis?

A

RBC production is able to compensate for the decrease in lifespan and so there is normal Hb levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

incompletely compensated haemolysis

A

RBC production is unable to keep up with the decreased Hb lifespan and so there is decreased Hb levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

clinical findings of haemolytic anaemia

A
  • jaundice (excess bilirubin which is a breakdown of haemoglobin)
  • pallor/fatigue
  • splenomegaly (increased workload lead yo an enlarged spleen)
  • dark urine: haemoglobinuria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

chronic findings of haemolytic anaemia

A
  • gallstones due to the accumulation of pigment (more bilirubin)
  • leg ulcers (NO scavenging)
  • Folate deficiency (using more folate to make RBCs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

laboratory findings of haemolytic anaemia

A
  • Increased reticulocyte count
  • Increased unconjugated bilirubin
  • Increased LDH (lactate dehydrogenase)
  • Low serum haptoglobin
  • Increased urobilinogen
  • Increased urinary haemosiderin
  • Abnormal blood film
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

blood film of haemolytic anaemia

A
  • reticulocytes
  • polychromasia (high no of immature RBCs
  • nucleated RBC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Spherocytosis

A

RBCs are sphere-shaped rather than bi-concave disk shaped as normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Elliptocytosis

A

red blood cells are elliptical rather than the typical biconcave disc shape.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the 3 components of red cell membrane structure

A

Lipid bilayer
Integral proteins
Membrane skeleton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

defects in vertical interaction proteins leads to

A

hereditary spherocytosis

  • Spectrin
  • Band 3
  • Protein 4,2
  • Ankyrin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

defects in the horizontal interaction proteins leads to

A

hereditary elliptocytosis

  • Protein 4.1
  • Glycophorin C
  • Spectrin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

hereditary spherocytosis

A

inherited in autosomal dominant fashion
bone marrow makes the biconcave RBC as normal, but as it goes round the circulation the membrane is lost and the RBC becomes spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

clinical features of hereditary spherocytosis

A
  • Asymptomatic to severe haemolysis
  • Neonatal jaundice
  • Jaundice, splenomegaly, pigment gallstones
  • Reduced eosin-5-maleimide (EMA) binding – binds to band 3
  • Positive family history
  • Negative direct antibody test
18
Q

management of hereditary spherocytosis

A

Monitor
Folic acid
Transfusion
Splenectomy

19
Q

Glucose-6-phosphate deficiency

A
  • Red blood cells break down (hemolysis) when the body is exposed to certain foods, drugs, infections or stress
  • Only has an effect when exposed to oxidant radicals: which denatures Hb forming aggregates & forms Heinz bodies
  • Oxidised membrane proteins which reduces RBC deformability
20
Q

G6PD deficiency

A

X-linked disorder

21
Q

prevalence of G6PD deficiency

A
  • Common in African, Asian, Mediterranean and Middle Eastern populations
  • Mild in African (type A), more severe in Mediterraneans (type B)
22
Q

Clinical features of G6PD deficiency

A

range from asymptomatic to acute episodes to chronic haemolysis

23
Q

What can trigger symptoms of G6PD

A 
Infections
Fava/ broad beans
Many drugs e.g.:
Dapsone
Nitrofurantoin
Ciprofloxacin
Primaquine
24
Q

Blood film of G6PD

A

Bite cells
Blister cells & ghost cells
Heinz bodies (methylene blue)

25
Q

pyruvate kinase deficiency

A

PK required to generate ATP

Essential for membrane cation pumps (deformability)

26
Q

genetics of PKD

A

autosomal deficiency

27
Q

Haemoglobinopathies

A

a group of recessively inherited genetic conditions affecting the haemoglobin component of blood. They are caused by a genetic change (mutation) in the haemoglobin

28
Q

Structure of haemoglobin

A

Ferrous iron + Protoporphyrin = Haem
2a + 2B = Globin
Haem + Globin = Haemoglobin

29
Q

Thalassaemias

A

Production increased/ decreased amount of a globin chain (structurally normal)

  • excess unpaired globin chains are unstable
  • RBCS damaged
  • Ineffective erthropoeisis
  • Haemolytic anaemia
30
Q

Variant haemoglobins

A

Production of a structurally abnormal globin chain

31
Q

two types of beta thalassaemia

A

Beta thalassemia trait: one gene on chromosome 16

Beta thalassemia major: two genes for betathalassemiaand no normal beta-chain gene (homozygous)

32
Q

diagnosis of thalassaemia trait

A 
Asymptomatic
Microcytic hypochromic anaemia
Low Hb, MCV, MCH 
Increased RBC
Often confused with Fe deficiency
HbA2 increased in b-thal trait –(diagnostic)
a-thal trait often by exclusion
globin chain synthesis (rarely done now)
DNA studies (expensive)
33
Q

beta thalassaemia trait

A
  • need transfusion in the first day of life
  • If don’t get a blood transfusion:
  • Failure to thrive
  • Progressive hepatosplenomegaly
  • Bone marrow expansion – skeletal abnormalities
  • Death in 1st 5 years of life from anaemia
34
Q

side effect of blood transfusion

A

Iron overload
Endocrinopathies
Heart failure
Liver cirrhosis

35
Q

sickle cell disease

A
  • Point mutation in the β globin gene: glutamic acid → valine
  • Insoluble haemoglobin tetramer when deoxygenated → polymerisation
  • sickle shaped cells
36
Q

clinical features of SCD

A 
Painful crises
Aplastic crises
Infections
Acute sickling:
Chest syndrome
Splenic sequestration
Stroke
Chronic sickling effects:
Renal failure
Avascular necrosis bone
37
Q

Laboratory features of SCD

A 
Anaemia
Hb often 65-85
Reticulocytosis
Increased NRBC
Raised bilirubin
Low creatinine
38
Q

how to confirm diagnosis of SCD

A

Solubility test
Expose blood to reducing agent
Hb S precipitated
Positive in trait and disease

39
Q

autoimmune haemolysis

A 
Idiopathic
Usually warm
IgG, IgM
Drug-mediated
Cancer associated
LPDs
40
Q

Alloimmune haemolysis

A 
Transplacental transfer:
Haemolytic disease of the newborn:
D, c, L
ABO incompatability
Transfusion related
Acute haemolytic transfusion reaction
ABO
Delayed haemolytic transfusion reaction
E.g Rh groups, Duffy

Semester 4: Haematology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions