Haemolytic anaemia

Question 1

What is haemolytic anaemia

Answer 1

anaemia due to shortened RBC survival

Question 2

approximately how long can RBC circulate without nuclei

Answer 2

120 days

Question 3

which system removes senescent RBC and organs included

Answer 3

reticuloendothelial system-liver and spleen

Question 4

what is reticulocytotic

Answer 4

increased number of reticulocytes (immature RBC)

Question 5

3 steps in haemolysis

Answer 5

shortened red cell survival (30-80 days)
bone marrow compensate with increased red blood cell production
increased young cells in circulation = reticulocytosis

Question 6

what is compensated haemolysis

Answer 6

RBC production able to compensate for decreased decreased RBC life span

Question 7

incompletely compensated haemolysis

Answer 7

RBC production unable to keep up with decreased RBC life span

Question 8

4 clinical findings of haemolytic anaemia

Answer 8

Jaundice
pallor/fatigue
splenomegaly
dark urine

Question 9

what is haemolytic crises

Answer 9

increased anaemia and jaundice with infections/precipitants

Question 10

what is aplastic crises

Answer 10

anaemia , reticulocytopenia with parvovirus infection

Question 11

what are 3 chronic clinical findings in haemolytic anaemia

Answer 11

Gallstones-pigment
leg ulcer
folate deficiency

Question 12

7 lab findings in haemolytic anaemia

Answer 12

• Increased reticulocyte count
• Increased unconjugated bilirubin
• Increased LDH (lactate dehydrogenase)
• Low serum haptoglobin protein that binds free haemoglobin
• Increased urobilinogen
• Increased urinary haemosiderin
• Abnormal blood film

Question 13

3 classification of haemolytic anaemia

Answer 13

inheritance
site of rbc destruction
origin of rbc damage

Question 14

2 types of inherited haemolytic anaemia and examples of both

Answer 14

hereditary - hereditary spherocytosis

acquired -paroxysmal nocturnal haemoglobinuria

Question 15

2 types of origin of RBC damage and examples of both

Answer 15

intrinsic - G6PD deficiency

extrinsic - Delayed haemolytic transfusion reaction

Question 16

2 types of site of RBC destruction and examples of both

Answer 16

intravascular - thrombotic thrombocytopenic purpura

extravascular- autoimmune haemolysis

Question 17

what is intravascular haemolytic anaemia

Answer 17

when the rbc is broken down in the circulation and the free hb is bound to plasma haptoglobins

Question 18

what is extravascular haemolytic anaemia

Answer 18

excessive removal of cell by macrophages of RE system

Question 19

what are the 2 haemogloinopathies

Answer 19

sickle cell disease

thalassaemia

Question 20

what is heriditary spherocytosis

Answer 20

defcts in vertical interaction in the red cell membrane

for example in spectrin, band 3 , protein 4.2 and ankyrin

Question 21

what is hereditary elliptocytosis

Answer 21

defects in horizontal interaction

for example in proetin 4.1, glycophorin c and spectrin-HPP

Question 22

4 management of hereditary spherocytosis

Answer 22

monitor
folic acid
transfusion
splenectomy

Question 23

Clinical features Hereditary spherocytosis

Answer 23

• 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

Question 24

3 metabolic pathway of RBC

Answer 24

glycolysis
HMS or hmp shunt
Rapoport luebering shunt

Question 25

what is the role of HMP shunt

Answer 25

generates NADPH and reduced glutathione

protects the cell from oxidative stress

Question 26

what are the effects of glucose-6- phosphate deficiency

Answer 26

Oxidative stress:

• oxidation of Hb by oxidant radicals results in denatured Hb aggregation and forms heinz bodies which bind to membrane
• oxidised membrane proteins reduces RBC deformability

Question 27

Role of pyruvate kinase

Answer 27

required to generate ATP-essential for membrane cation pumps

Question 28

what are the effects of pyruvate kinase deficiency

Answer 28

cells lose large amount of potassium & water, becoming dehydrated & rigid

Question 29

Genetics of G6PD deficiency and PK deficiency

Answer 29

G6PD- X linked

PK- autosomal recessive

Question 30

what 2 things make up haem

Answer 30

ferrous iron and protoporphyrin IX

Question 31

what are the globin chains of HbA, HbA2 and HbF

Answer 31

HbA- 2 alpha and 2 beta
HbA2- 2 alpha and 2 delta
HbF- 2 alpha and 2 gamma

Question 32

what are the 2 types of globin disorder

Answer 32

thalassaemia : production of increases or decreased amount of globin chain which is structurally normal
variant haemoglobin : production of a structurally abnormal globin chain

Question 33

what is thalassaemia

Answer 33

imbalanced alpha and beta chain production

Question 34

what can excess unpaired globin chain cause

Answer 34

• they are unstable
• can precipitate and damage RBC and their precursors.
• ineffective erythropoiesis in bone marrow
• Haemolytic anaemia

Question 35

Diagnosis of thalassaemia trait

Answer 35

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

Question 36

what are some of the clinical findings in sickle cell disease

Answer 36

Painful crises
aplastic crises
infection 
acute sickling: 
- chest syndrome
-splenic sequestration 
- stroke
Chronic sickling effects :
-renal failure
-avascular necrosis bone

Question 37

what are some of the laboratory findings in sickle cell disease

Answer 37

Anaemia
reticulocytotic
increased NRBC 
raised bilirubin 
low creatinine

Question 38

2 confirmation tests for sickle cell anaemia

Answer 38

solubility test (Hb S precipitated )
electrophoresis