anaemia

Question 1

what is anaemia

Answer 1

reduction in amount of hb in a given vol of blood (below what is expected in comparison with healthy subject of same gender and age)

Question 2

what are the mechanisms leading to anaemia

Answer 2

reduced production of red cells/hb in bone marrow
loss of blood from body
reduced survival of red cells in circulation
pooling of red cells in enlarged spleen

Question 3

how can we determine cause of anaemia

Answer 3

classification on basis of cell size

helpful to look at mcv (average size of rbcs)

Question 4

what does microcytic mean

Answer 4

describes red cells that are smaller than normal/ anaemia with small red cells

Question 5

what does normocytic means

Answer 5

describes red cells with normal size/anaemia with large red cells

Question 6

what does macrocytic mean

Answer 6

red cells that are larger than normal/ anaemia with large cells

Question 7

how can we tell if red cells are normachromic

Answer 7

have about a third of diameter is pale - this is result of disc shape

Question 8

what does hypochromia mean

Answer 8

cells have larger area of central pallor than normal more than 1/3 of diameter
- results from lower hb conc and flatter cells

Question 9

why do hypochromia and microcytosis oftern go together

Answer 9

they both result from defect in hb synthesis

not enough hb = smaller cells and conc of hb reduced

Question 10

what are some common causes of microcytic anaemia

Answer 10

defect in haem synthesis: iron def anaemia and anaemia of chronic disease
defect in globin synthesis:
alpha thalasaemia
beta thalasaemia

Question 11

what are some causes of iron def anaemia

Answer 11

• increased blood loss: commonest cause in adults, hookwork, menorrhagia, bleeding due to colon cancer
• insufficient intake - dietary
• decreased absorption - coeliac disease, h- pylori gastritis
  increased requirements - physiological, pregnancy and infancy
  meds e.g aspirin/nsaids

Question 12

what would you expect to see in bloods of individual with anaemia of chronic disease

Answer 12

low hb
low/normal mcv
high ferritin!
low serum iron
low/normal transferrin
high esr

Question 13

what would you expect to see in bloods of individual with iron def anaemia

Answer 13

low hb
low mcv
low ferritin
low serum iron
high transferrin
may be high esr

Question 14

what is macrocytic anaemia

Answer 14

average cell size is increased

usually result from abnormal haemopoiesis so red cell precursors continue to synthesise hb but fail to divide normally

Question 15

what is a cause of macrocytic anaemia

Answer 15

megaloblastic erythropoiesis
- refers to delay in maturation of nucleus while cytoplasm continues to mature and cell continues to grow.
megaloblasts usually seen in bone marrow

Question 16

what is megaloblastic anaemia

Answer 16

caused by deficiency of b12/folate

Question 17

what would yo expect to see in megaloblastic blood film

Answer 17

anaemia
tear drop cells
hypersegmented neutrophils
oval macrocytes

Question 18

what are some common causes of macrocytic anaemia

Answer 18

lack of b12/folic acid = megaloblastic anaemia
use of drugs interfering with dna synthesis
liver disease and ethanol toxicity
haemolytic anaemia

Question 19

what are some mechanisms of normocytic anaemia

Answer 19

recent blood loss
failure of production of red cells
pooling of red cells in spleen

Question 20

causes of reduced red cell production

Answer 20

iron def anaemia
anaemia of chronic disease
megaloblastic anaemia

Question 21

what is haemolytic anaemia

Answer 21

form of anaemia due to hemolysis, abnormal breakdown of rbcs, either in blood vessels or elsewhere in body

Question 22

what are some symptoms of haemolytic anaemia

Answer 22

fatigue and shortness of breath
- breakdown of red cellls also leads to jaundice and increases risk of particular long term complications e.g gallstones and pulmonary hypertension

Question 23

what can hereditary haemolytic anaemia be due to

Answer 23

defects in rbc membrane - hereditary spherocytosis
defects in hb production- thalasaemia, sickle cell disease
defective red cell metabolism- g6pd def

Question 24

what can acquired haemolytic anaemia be due to

Answer 24

caused by immune mediated causes, drugs, others e.g autoimmune haemolytic anaemia (more common in sle,ra…)
- any causes of hypersplenism

Question 25

what does erythrocyte function depend on?

Answer 25

integrity of membrane
hb structure and function
cellular metabolism

Question 26

differences between haemolysis and haemolytic anaemia

Answer 26

haemolysis = lowered rbc lifespan <120 days

haemolytic anaemia = cannot compensate for lowered rbc count

Question 27

how do patients with chronic haemolysis get treated?

Answer 27

folic acid - due to increased dna synthesis

splenectomy (if severe) to increase red cell lifespan because spleen takes out rigid rbcs (spherocytes) out circulation

Question 28

what should make you consider haemolysis

Answer 28

elevated reticulocytes/ldh/unconjugated bilirubin

Question 29

what test can be used to confirm immune mechanism in haemolysis

Answer 29

DAT - Direct anti - globulin test

Question 30

what does a high reticulocyte count mean

Answer 30

bone marrow responds to haemolytic anaemia by producing more rbcs

Question 31

what are some oxidative stressors for g6pd deficiency

Answer 31

broad beans e.g fava beans
quinine derived drugs
certain antibiotics
infections
naphthalene

Question 32

how to treat iron deficiency anaemia

Answer 32

oral iron supplements with orange juice

iv iron

Question 33

what is anaemia of chronic disease put simply

Answer 33

body stores iron

Question 34

what are some common causes of anaemia of chronic disease?

Answer 34

infections e.g tb/hiv
ra/ other autoimmune disorders
malignancy