iron pres swetha

8/7/2019 iron pres swetha

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IRON IN HEALTHIRON IN HEALTHAND DISEASEAND DISEASE


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IRON METABOLISMIRON METABOLISM

INTRODUCTORY BACKGROUNDINTRODUCTORY BACKGROUND

Essential element in all living cells

Transports and stores oxygen

Integral part of many enzymes

Usually bound to other molecules

Quantity of body iron carefully

controlled


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BODY IRON DISTRIBUTIONBODY IRON DISTRIBUTION

A. Metabolically Active Iron:

Haemoglobin

Serum iron bound to a protein

transferrin in blood

Tissue Iron: in cytochromes andenzymes

Myoglobin: oxygen reserve in muscles


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APPROXIMATE DISTRIBUTION OFAPPROXIMATE DISTRIBUTION OF

BODY IRON IN A MANBODY IRON IN A MAN

Hemoglobin 2000mgStorage Iron 1000mg

Myoglobin iron 130mg

Labile Pool 80mg

Other tissue Iron 8mgTransport Iron 3mg


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BODY IRON DISTRIBUTIONBODY IRON DISTRIBUTION

B. Storage Iron:

Ferritin: found in blood, tissue fluids, andcells

Haemosiderin: found in macrophages andassessed by staining bone marrow withPrussian Blue stain


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DIETARY SOURCES OF IRONDIETARY SOURCES OF IRON

Inorganic Iron eg lentils Organic iron eg beef

DAILY IRON REQUIREMENT 10-15mg/day (5-10% absorbed)


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IRON ABSORPTIONIRON ABSORPTION Iron kept soluble and in ferrous state by

gastric acid

Absorbed mainly in duodenum

Quantity absorbed regulated by enterocyte

Multiple proteins involved in control of iron

transport Haem iron enters the enterocyte through

different process than inorganic iron


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ABSORPTION OF IRON

Haem

Fe+++

Fe++

Ferritin

Tf

Tf-

Fe+++ Fe++Fe++

Enterocyte GutGut


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IRON ABSORPTION (cont)IRON ABSORPTION (cont)

Transferrin bound iron in plasma

delivered to body cells according to

cellular iron requirements

Note:

Only 20% of plasma bound iron derivedfrom gut. Most plasma iron is derived from

breakdown of senescent red cells.


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WHAT YOU NEED TO KNOWWHAT YOU NEED TO KNOW

Daily requirements and dietary sources ofiron

Where iron is absorbed in the gut Control of iron balance at level of enterocyte

How body stores of iron are assessed

Proteins involved in regulation of iron


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IRON DEFICIENCYIRON DEFICIENCY

Commonest cause of anaemia worldwide

Cause of chronic ill health

May indicate the presence of importantunderlying disease eg. blood loss from

tumour


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EVOLUTION OF IRONEVOLUTION OF IRON

DEFICIENCY ANAEMIADEFICIENCY ANAEMIA

Earliest stage : depletion of body

iron stores only

Biochemical iron deficiency

without anaemia

Iron deficiency anaemia


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CLINICAL FEATURES IRONCLINICAL FEATURES IRON

DEFICIENCYDEFICIENCY

Symptoms eg. fatigue, dizziness, headache

Signs eg. pallor, glossitis, angularcheilosis, koilonychia, Plummer Vinsonsyndrome

Koilonychia Glossitis


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Angular Cheilosis

or Stomatitis

CLINICAL FEATURES OF IRON DEFICIENCYCLINICAL FEATURES OF IRON DEFICIENCY


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Absent iron stores in bone marrowABSENT IRON STORES IN BONEABSENT IRON STORES IN BONE

MARROW IN IRON DEFICIENCYMARROW IN IRON DEFICIENCY

Iron deficiencyNormal control


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PRINCIPLES OF TREATMENTPRINCIPLES OF TREATMENT

Use oral iron ( not enteric coated tablets )

Replace iron deficit in total :

Restore haemoglobin and MCV to normal

Replenish iron stores

Establish and treat the cause


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LOOK FORLOOK FOR

THE CAUSETHE CAUSEOF IRONOF IRON

DEFICIENCYDEFICIENCY


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CAUSES OF IRON DEFICIENCYCAUSES OF IRON DEFICIENCY

Increased physiologic demand

eg. pregnancy, lactation, rapid

growth

Blood loss from GI tract, uterus,

haemoglobinuria

Malabsorption

Diet


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WHAT YOU NEED TO KNOWWHAT YOU NEED TO KNOW

Symptoms and signs of iron deficiency

Laboratory diagnosis of iron deficiency Differential diagnosis of a microcytic

hypochromic anaemia

Importance of finding a cause for irondeficiency

Principles of treatment


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IRON OVERLOADIRON OVERLOAD


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CAUSES OF IRON OVERLOADCAUSES OF IRON OVERLOAD

Hereditary haemochromatosis

Multiple transfusions Liver disease

Prolonged use medicinal iron

Ineffective erythropoiesis African Iron Overload


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EFFECTS OF IRON OVERLOAD

Non-transferrin-bound iron

(NTBI) circulates in the plasma

Excess iron promotes

the generation of free

hydroxyl radicals,

propagators of oxygen-related tissue damage

Liver cirrhosis/

fibrosis/cancer

Insoluble iron complexes

are deposited in body

tissues and end-organtoxicity occurs

Diabetes

mellitusGrowth

failure

Capacity of serum transferrin

to bind iron is exceeded

Iron overload

Cardiac

failureInfertility

HSC

senescence

(Fenton Reaction)

O2- + H2O2 O2+OH- + HO


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WHEN DOES IRON BECOME AWHEN DOES IRON BECOME A

PROBLEM?PROBLEM?

Normally 2.5 3.5g of iron in thebody.

Tissue damage when total body ironis 7 15 g


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TREATMENT AND PREVENTIONTREATMENT AND PREVENTION

Phlebotomy until ferritin

iron pres swetha

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