Disorders of Iron Metabolism

Question 1

Inflammatory cytokines in chronic disease have what effect, which causes anaemia of chronic disease?

Answer 1

There is increased transcription of ferritin mRNA causing ferritin synthesis to be increased / increases plasma hepcidin to block ferroportin mediated release of iron

Question 2

What is the primary cause of iron overload?

Answer 2

Hereditary haemochromatosis

Question 3

What is the brief pathophysiology behind hereditary haemochromatosis?

Answer 3

Long term excess iron absorption with storage in the parenchymal tissues rather than in macrophages

Question 4

The commonest form of hereditary haemochromatosis is due to mutations in which gene?

Answer 4

HFE gene

Question 5

When does hereditary haemochromatosis usually present?

Answer 5

Middle age or later

Question 6

What are some clinical features of hereditary haemochromatosis?

Answer 6

Weakness/fatigue, joint pains, impotence, cirrhosis, diabetes, cardiomyopathy

Question 7

What happens to each of the following to be diagnosed with hereditary haemochromatosis: a) ironn levels? b) transferrin saturations? c) serum ferritin?

Answer 7

a) > 5g b) > 50% c) > 300mcg/l in men and > 200mcg/l in pre-menopausal women

Question 8

Is a liver biopsy needed to diagnose hereditary haemochromatosis?

Answer 8

No

Question 9

How is hereditary haemochromatosis treated?

Answer 9

Weekly venesection of 400-500ml (getting rid of 200-250mg of iron)

Question 10

What is the initial aim of venesection in hereditary haemochromatosis?

Answer 10

To exhaust the iron stores, ferritin < 20mcg/l

Question 11

After the initial venesection for hereditary haemochromatosis, ferritin levels should be kept at what?

Answer 11

< 50mcg/l

Question 12

Should family be tested for hereditary haemochromatosis?

Answer 12

Yes, first degree relatives get tested. You should wait until children are adults before testing them.

Question 13

Why is family screening important for hereditary haemochromatosis?

Answer 13

May be asymptomatic until there is irreversible end organ damage

Question 14

What is the main cause of secondary iron overload?

Answer 14

Iron loading anaemias - from repeated red cell transfusion or excessive iron absorption related to overactive erythropoiesis

Question 15

What are some causes of massive ineffective erythropoiesis which would result in patients having to receive red cell transfusions?

Answer 15

Thalassaemias and sideroblastic anaemia, myelodysplasia

Question 16

What is used to treat iron overload from excess red cell transfusions?

Answer 16

Iron chelating agents