Iron Deficiency Anemia Overview

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Questions and Answers

What effect does hypoxia have on hepcidin synthesis?

Suppresses hepcidin synthesis (correct)

Increases hepcidin synthesis

Increases iron absorption

Has no effect on hepcidin synthesis

Increased erythropoiesis leads to an increase in hepcidin synthesis.

False

What laboratory finding is indicated by low ferritin levels?

Iron deficiency

Iron is primarily transported in the bloodstream by ______.

transferrin Signup and view all the answers

Match the following types of anemia with their causes:

Thalassaemia = Genetic mutations affecting haemoglobin production Anaemia of chronic disease = Chronic inflammation leading to low iron availability Sideroblastic anaemia = Deficiency of Aminolevulinic Acid (ALA) enzyme Iron deficiency anemia = Insufficient iron intake or absorption Signup and view all the answers

Which of the following mechanisms is responsible for iron absorption in the duodenum?

Divalent Metal Transporter 1 (DMT-1) Signup and view all the answers

Transferrin is a protein that stores iron in the liver and spleen.

False Signup and view all the answers

Name one of the primary causes of iron deficiency anemia.

Blood loss, Inadequate intake, Malabsorption, or Increased demand Signup and view all the answers

Iron is primarily stored in the body as __________.

ferritin Signup and view all the answers

Match the following terms related to iron regulation with their functions:

Transferrin = Transports iron in the bloodstream Ferritin = Stores iron in cells DMT-1 = Facilitates iron absorption in the intestine Hepcidin = Regulates iron homeostasis by inhibiting absorption Signup and view all the answers

What is the effect of binding of IRP to the Iron Response Element (IRE) when iron levels are low?

Increased translation of mRNA Signup and view all the answers

In iron overload, IRP/IRE binding is increased.

False Signup and view all the answers

What is the role of hepcidin in iron metabolism?

To regulate iron absorption and release from macrophages Signup and view all the answers

Hepcidin is produced in the ______.

liver Signup and view all the answers

Match the following regulatory elements with their functions:

TfR1 = Increased iron uptake DMT-1 = Iron transport across cell membranes Ferritin = Iron storage Hepcidin = Regulates iron absorption Signup and view all the answers

What happens to TfR2 levels when iron levels are elevated?

TfR2 levels decrease Signup and view all the answers

Haemochromatosis is related to a deficiency in iron absorption.

False Signup and view all the answers

How does increased hepcidin affect iron absorption in the small intestine?

It reduces iron absorption Signup and view all the answers

Study Notes

Iron Deficiency Anemia

Symptoms of Low Hemoglobin (Hb):
- Tiredness
- Breathlessness
- Pallor
- Cardiovascular symptoms
4 Main Causes of Iron Deficiency Anemia (IDA):
- Blood loss
- Inadequate iron intake
- Malabsorption
- Increased iron demand

Iron Regulation Cycle

Dietary iron is absorbed by microvilli in the small intestine (duodenum).
Iron enters the bloodstream and is transported by transferrin (protein) to bone marrow or the liver.
Iron is used in bone marrow for red blood cell (RBC) production.
Iron is stored in the liver as ferritin.

Dietary Iron Absorption and Regulation

Dietary iron intake is approximately 10-15 mg/day, with only about 1 mg absorbed.
Iron from meat is absorbed via haem receptors.
Non-haeme iron is reduced to Fe2+ by ferrireductase, then absorbed via DMT-1.
Absorbed iron is either stored as ferritin or enters the bloodstream via ferroportin.
Transferrin transports iron to bone marrow or other tissues

Iron Storage

Iron is stored as ferritin or haemosiderin.
Ferritin contains an iron-hydroxide-phosphate compound.

Iron Regulation

Iron levels are controlled by four key stages:
- Iron import from the intestine to the enterocyte via DMT-1
- Iron export from the enterocyte into the circulation via ferroportin
- Ferritin synthesis
- TfR-1 (transferrin receptor 1) synthesis
Gene Regulation:
- Iron status controls ferritin, TfR1, and DMT-1 genes.
- High iron levels increase ferritin production, and decrease TfR1 and DMT-1.
- Low iron levels decrease ferritin production, and increase TfR1 and DMT-1
Hormone Regulation (Hepcidin):
- A polypeptide hormone produced in the liver.
- Its production is controlled by iron levels, inflammation, cytokines, erythropoiesis, and hypoxia.
- Increased hepcidin leads to reduced iron absorption in the small intestine and reduced release of iron from macrophages.

Laboratory Findings

FBC: Low hemoglobin (Hb), low mean corpuscular volume (MCV), low mean corpuscular hemoglobin (MCH).
Blood film: Microcytic/hypochromic anemia
Red Cell Distribution Width (RDW): Measures variation in red blood cell size (higher value = greater variation)
Ferritin: Low levels
Zinc Protoporphyrin (ZPP): Elevated levels
Serum iron: (Not very useful)
Total Iron Binding Capacity (TIBC): Low transferrin saturation

Differential Diagnosis of Microcytic/Hypochromic Anemia

Thalassemias: Genetic mutations affecting hemoglobin production
Anemia of chronic disease:
Sideroblastic anemia: Deficiency of aminolevulinic acid enzyme causing iron accumulation in mitochondria of red blood cells.

Additional Notes

Iron accounts for 20% of its body weight.
Old red blood cells are broken down by macrophages, releasing iron from hemoglobin, which the body transports to bone marrow for reuse.

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Description

Explore the key aspects of iron deficiency anemia, including its symptoms, causes, and the regulation of dietary iron absorption. This quiz covers how iron is utilized and stored in the body and the processes involved in the formation of red blood cells. Test your knowledge about this crucial health topic.