Lecture 21

Question 1

Issues of Iron overload

Answer 1

• acute iron toxicity
• hereditary haemochromatosis
• african iron overload
• other iron overload conditions

Question 2

hereditary haemochromatosis is a what condition

Answer 2

autosomal recessive condition

Question 3

you have poor control of what when you have hereditary haemochromatosis

Answer 3

poor control of iron absorption

Question 4

what happens in hereditary haemochromatosis

Answer 4

iron accumulates in liver, pancreeas and heart muscle which impacts their function

Question 5

When should effective treatment start for hereditary haemochromatosis

Answer 5

treatment is very effective if started early

Question 6

what are the biochemical indices that would indicate hereditary haemochromatosis (serum ferritin and transferrin saturation)

Answer 6

serum ferritin :
>300ug/L males
>200ug/L females

transferrin saturation :
>45% men and women

repeated in a fasting sample

Question 7

Clinical assessment

Answer 7

a medical history and a physical examination are the clinical methods used to detect signs, (observations made by a qualified examiner) and symptoms (manifestations reported by the patient) associated with malnutrition

Question 8

clinical assessment has to be done alongside …… why ?

Answer 8

alongside other measures of nutritional assessment because otherwise someone could be diagnosed as something that they don’t have

Question 9

what are the individual level uses of iron status indicators

Answer 9

• screening
• clinical assessment

Question 10

when looking at an individuals iron status that is close to but not below the cut offs what usually happens and how is that different to population status

Answer 10

they will usually be treated with iron medication, different to population level were cut offs are strictly used

Question 11

population level uses of iron status indicators

Answer 11

• prevalence estimates of deficiency
• planning appropriate interventions
• evaluating impact of interventions

Question 12

what is the context of individual assessment of Fe status

Answer 12

• availability of assay
• usefulness
• cost

Question 13

what are the indices of individual assessment of Fe status

Answer 13

• haemoglobin
  serum ferritin and C-reactive protein ?
  serum Fe, transferrin saturation = if concerned about possibility of iron overload

Question 14

what type of index data is most useful in population practice

Answer 14

combining indices to look at things such as iron deficiency anaemia etc, instead of things such as low haemoglobin

Question 15

what are the factors affecting validity of cut offs

Answer 15

• method of blood collection
• fasting status / time of day
• assay / equipment used
• infection (inflammation)
• environment and other confounding factors
• genetics

Question 16

what does fasting status / time of day affect validity of cut offs for iron

Answer 16

very highly changeable depending on the time of the day

transferrin saturation changes over the day, usually high in the morning and then decreases throughout the day

Question 17

Inflammation what happens

Answer 17

-phase response to inflammation, infection and malignancy
- blocks the release of Fe from reticuloendothelial system
- increases translation of ferritin
- leads to shortage of Fe in bone marrow

Question 18

when inflammation is present why does your body try store iron and remove it from circulation

Answer 18

because bacteria need iron in order to grow so your body doesn’t want iron to be where bacteria is

Question 19

Iron indices and infection: Measure of infection

Answer 19

C-reactive protein

a-1-acid glycoprotein

a-1-antichymotrypsin

Question 20

what are other sources of variation in iron indices

Answer 20

• oral contraceptive agents (decrease transferrin saturation)
• smoking (increases haemoglobin)
• altitude (increases haemoglobin)
• “sports anaemia” (decreases haemoglobin)
• dehydration (increases indices)

Question 21

what is the main cause of anaemia

Answer 21

iron deficiency

Question 22

anaemia can also be caused by

Answer 22

• infection (malaria, HIV)
• decreased erythropoiesis (bone marrow depression, B12 or folate deficiency)
• genetic disorders (thalassemia, sickle cell anaemia)

Question 23

thalassemia presents

Answer 23

abnormal cell shapes

Question 24

Microcytic blood cells

Answer 24

If you don’t have enough iron to make enough HB then you are going to have small cells

Question 25

Mesoblastic blood cells

Answer 25

If a cell cant dividf when being formed then they are still going to have their nucleus apart of them they are much larger and there are less of them and it decreases the amount hemoglobin

Question 26

if someone has
low haemoglobin,
normal mean cell volume,
low - norm transferrin saturation,
high-norm ZPP
high ferritin

what do they likely have

Answer 26

chronic disease

The cells you’ve got are fewer but they are normal

Question 27

if someone has
low haemoglobin,
high mean cell volume,
high-norm transferrin saturation,
normal ZPP
normal ferritin

what do they likely have

Answer 27

macrocytic anaemia

These are big cells and iiron isnt the problem its make the RBC that is the problem

Question 28

if someone has
low haemoglobin,
low mean cell volume,
high transferrin saturation, norm ZPP
norm ferritin

what do they likely have

Answer 28

thalassemia

Less heam and smaller cells

Question 29

Low everything but high ZPP

Answer 29

IDA

Question 30

the use of haemoglobin results alone is an

Answer 30

overestimate of prevalence of IDA