haemolysis

Question 1

haemolysis?

Answer 1

premature red cell destruction

Question 2

why particularly susceptible to damage?

Answer 2

biconcave shape limited metabolic reserve (rely exclusively on glucose metabolism for energy), can’t generate new proteins once in the circulation

Question 3

compensated haemolysis?

Answer 3

increased red cell destruction compensated by increased red cell production i.e. Hb maintained

Question 4

haemolytic anaemia

Answer 4

increased rate of red cell destruction exceeding bone marrow capacity for red cell production i.e. Hb falls

Question 5

consequences of haemolysis?

Answer 5

erythroid hyperplasia (increased bone marrow red cell production)
excess red cell breakdown products e.g. bilirubin

Question 6

rely on detecting therefore the breakdown products of red cells and the increased red cell production

Answer 6

y

Question 7

bone marrow response to haemolysis?

Answer 7

reticulocytosis and erythroid hyperplasia

Question 8

are reticulocytes nucleated?

Answer 8

NO

Question 9

why would a blood film in a patient with haemolysis have polychromasia?

Answer 9

ribosomal DNA in reticulocytes have RNA that shows blue ray appearance

Question 10

are reticulocytes diagnostic of hs?

Answer 10

no, they are a response to bleeding, iron therapy and iron deficiency anaemia

Question 11

supravital stain?

Answer 11

supravital stain staining ribosomal RNA

Question 12

automated reticulocyte counting

Answer 12

ribosomal RNA is labelled with a flourochrome and fluorescent cells are counted

Question 13

bone marrow erythroid hyperplasia

Answer 13

.

Question 14

extravascular hs occurs in ?

Answer 14

liver and spleen

Question 15

intravascular?

Answer 15

cells destroyed within the circulation

Question 16

which is commoner - intra or extravascular?

Answer 16

extra

Question 17

what sort of signs of extravascular would you get?

Answer 17

hyperplasia at sites of destruction i.e. splenomegaly or hepatomegaly

Question 18

normal products are in excess

Answer 18

.

Question 19

intravascular haemolysis

Answer 19

red cells destroyed in circulation, spilling their contents

Question 20

4 things you see?

Answer 20

haemoglobinaemia, methaemalbuminaemia, haemoglobinuria (pink urine, turns black on standing, haemosiderinuria

Question 21

what is methaemalbumin?

Answer 21

methaem binds to albumin

Question 22

these are ABNORMAL products

Answer 22

intravascular homeless may be life threatening

Question 23

when would you get intravascular haemolysis?

Answer 23

ABO incompatible blood transfusion, G6PD deficiency, malaria, PNH, PCH (rare)

Question 24

extravascular ?

Answer 24

all other causes of haemolysis

Question 25

investigations?

Answer 25

FBC, reticulocyte count, serum unconjugated bilirubin, serum haptoglobins, urinary urobilinogen

Question 26

what does haptoglobin bind?

Answer 26

free haemoglobin

Question 27

blood film might show?

Answer 27

``` mechanical damage (red cell fragments) oxidative stress (Heinz bodies) Others i.e. sickle cell disease ```

Question 28

premature destruction of normal red blood cells. autoimmune haemolysis?

Answer 28

warm IgG - idiopathic, autoimmune disorders, lymphoproliferative disorders, drugs, infection

Question 29

cold IgM?

Answer 29

idiopathic, infections, lymphoproliferative disorders

Question 30

what does direct coombs test identify?

Answer 30

antibody bound to own red cells

Question 31

alloimmune haemolysis?

Answer 31

Immediate IgM - predominantly intravascular | delayed IgI - predominantly extravascular

Question 32

passive transfer of the antibody

Answer 32

haemolytic disease of the newborn | rhd, abo incompatibility, others eg anti kell

Question 33

haemolytic transfusion reaction iMMediate Mintravascular. delayed Gextravascular

Answer 33

.

Question 34

mechanical red cell destruction

Answer 34

DIC, haemolytic uraemic syndome, TTP, leaking heart calve, infections ie malaria

Question 35

mechanical damage caused - valve related - red cell fragmentation.

Answer 35

MAHA - microangiopathic haemolytic anaemia

Question 36

in burns related homeless

Answer 36

microspherocytes, red cells are sheared as they pass through damaged capillaries. only seen in severe burns

Question 37

membrane defects are all very rare

Answer 37

ziev's syndrome, vitamin e deficiency, PNH

Question 38

zieves syndrome

Answer 38

haemolysis, alcoholic liver disease, hyperlipidaemia

Question 39

anaemia, polychromatc macrocytes, irregularly contracted cells?

Answer 39

zieves syndrome

Question 40

hereditary spherocytosis?

Answer 40

pheric red blood cells which are destroyed in the spllen

Question 41

what would you see in spherocytosis

Answer 41

splenomegaly

Question 42

g6pd deficiency -

Answer 42

no glutathione, no atp. haemolysis

Question 43

g6pd deficiency - failure to cope with oxidative stress

Answer 43

y

Question 44

dapsone therapy can cause keratocyte and irregularly contracted cell

Answer 44

in beta thalassaemia major, get bony deformities of chronic erythroid hyperplasia and marrow cavity expansion

Question 45

why can g6pd deficiency cause intravascular haemolysis

Answer 45

involved in production of NADPH, which i.e. needed for glutathione production