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Iron Deficiency Anemia
Nada Mohamed Ahmed ,MD, MT (ASCP)i
• Definition .• Physiology of iron. • Causes of iron deficiency.• At risk group .• Stages of IDA (pathophysiology).• Symptoms (clinical presentation ).• Lab diagnosis.
LEARNING OBJECTIVES
Definition Iron Deficiency Anemia
• Iron deficiency anemia is a condition in which hemoglobin synthesis has been defected due to reduce or lacking of iron in the body .
• Iron is an essential mineral that is needed to form hemoglobin, an oxygen carrying protein inside red blood cells.
Physiology of iron:
• 1- distribution of iron • 2- source of iron • 3-Iron absorption • 4-Iron transport• 5-storage of iron
) distribution (of iron Iron in human body
• Total Iron in human body averages 4 to 5 grams which is distributed as:
1. 65% in form of Hb. (Hemoglobin iron)2. 4% in form of mayoglobin. respiratory
enzymes 3. (plasma iron ) ( transport iron) 0.1% is
combined with protein transferrin in blood4. storage iron 15%−30% stored for later use,mainly
in reticuloendothelial system of bone marrow and liver parenchymal cells, principally in form of ( ferritin and hemosidirin )
Absorption
• Ferrous, Fe2+, most soluble = most absorbable
AbsorptionDuodenal Lumen Duodenal Mucosa Plasma
B2-microglobulin
HFE
DMT1
B3 integrin
MucinFe++
Fe++ Fe++
Fe2+
Fe3+
Mobilferritin
Heme-Protein
Heme+
Polypeptides
Heme
Biliverdin Bilirubin Bilirubin
Heme
OxigenaseCO CO
paraferritin
Fe2+ Fe2+
Fe3+
Transferritin
Ceruloplasmin
Ferroportin
IRON ABSORPTION
Haem iron is not affected by ingestion of
other food items. The haem molecule is absorbed intact and the iron is released in the mucosal cells.
IRON ABSORPTION (2)
The absorption of(free) non-haem iron varies greatly from 2% to 100% because it is strongly influenced by:
The iron status of the bodyThe solubility of iron saltsIntegrity of gut mucosaPresence of absorption inhibitors or
facilitators
INHIBITORS OF IRON ABSORPTION
Food with polyphenol compoundsVegetables such as spinach and spices Beverages like tea, coffee, cocoa and wine. A single cup of tea taken with meal reduces iron absorption by up to 11%.
IRON TRANSPORTTransferrin is the major protein responsible for transporting iron in the body.Transferrin receptors, located in almost all cells of the body, can bind two molecules of transferrin.Both transferrin concentration & transferrin receptors are important in assessing iron status.
STORAGE OF IRONTissues with higher requirement for iron
( bone marrow, liver & placenta) contain more transferrin receptors.
Once in tissues, iron is stored as ferritin & hemosiderin compounds, which are present in the liver, RE cells & bone marrow.
Causes of iron deficiency
Increase demands of iron
Increase iron loss
Decrease iron intake
AT RISK GROUPSInfants
Under 5 children
Children of school age
Women of child bearing age
• Iron deficiency anemia is the most common form of anemia and it develops over time if the body does not have enough iron to manufacture red blood cells.
• Without enough iron, the body uses up all the iron it has stored in the liver, bone marrow and other organs.
Stages of IDA (pathophysiology)
• Once the stored iron is depleted, the body is able to make very few red blood cells.
• If erythropoietin is present without sufficient iron, there is insufficient fuel for red blood cell production
• The red blood cells that the body is able to make are abnormal and do not have a normal hemoglobin-carrying capacity, as do normal red blood cells.
Clinical Presentation• Iron-deficiency anemia can cause:brittle nails
cracks in the sides of the mouth
Extreme fatigue (tiredness)
chest pain
• Pale skin
• Dizziness or lightheadedness
Symptoms (clinical presentation ).
an enlarged spleenCold hands and feetfrequent infections.Irritabilityshortness of breathswelling or soreness of the tongue
LAB FINDINGS IN IDA
Complete blood count(Microcytic hypochromic) anaemiaLow Hb level (< 11.0 g/dl)Low MCV, MCH, MCHCLow serum ferritin
High iron binding capacity
