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Lecture 2 Assist. Prof Dr. Hussein Naji Al-Shammari

Iron Deficiency Anemia

Iron Deficiency is the most common cause of anaemia world wilde. It is the most common cause of microcytic hypochromic anemia (Low MCV,MCHC, MCH). It is the most common micronutrient deficiency anaemia in the world affecting 24% of the world population. This is because Poverty, bad dietary habits, and excess pathological blood loss .

DIETARY IRON:

There are 2 types of iron in the diet; haem iron and non-haem iron
a. Haem iron is present in Hb , muscle meat, and liver.
b. Non-haem iron is obtained from cereals, vegetables & beans
c. The average diet contains 10—15mg iron from which 5-10% absorbed (1—1.5mg/day) to balance the 1—1.5md/day iron loss.

STORAGE and Iron disruption OF IRON


Iron Distribution in the body :
Site
Male g
female
Percentage of total
Hb (circulating)
2.4
1.7
65%
Ferritin /Hemosiderin (storage)
Liver, bone marrow, spleen
0.3—1.5
0.2—1.0
30%
myoglobin
0.15
0.12
3.5%
Enzymes
0.02
0.015
0.5%
Transferrin bound iron (plasma)
0.004
0.003
0.1%
Total
3—5 g
2—3 g

Iron is stored as ferritin & hemosiderin compounds.

1. Ferritin : water soluble protein-iron complex in tissue and plasma, contain 20% wt iron. Ferritin level reflects amount of stored iron in the body & it is the best mirror of iron in the storage in iron deficiency anaemia.

2. Hemosiderin : insoluble protein-iron complex as storage iron, visible in macrophages after staining by Perls (Prussian blue) reaction.

Daily Iron requirments ( mg/day):

Group
Lossby; GIT, UT, Skin, hair loss
Growth
mense
pregnancy
total
children
0.5
0.5

1.0
female 12—15 year
0.5 –1
0.5
0.5—1

1.6—2.5

menstruation
0.5—1
00
0.5—1

1—2
pregnancy
0.5—1
00

1—2
1.5—3
postmenopausal
0.5—1
00

0.5—1

Adult male
0.5—1
00

0.5—1

Iron loss : 1.0 mg of iron is lost each day usually balanced by dialy absorbtion RISK GROUPS for iron deficiency:
1. Children of pre—school and school age both sex.
2. Adolescent girls.
3. Women of child bearing age (pregnant and lactation).

Iron absorbtion is restricted to the needs of the body

Factors favoure absorption
Factors reducing absorption
Hem iron
Inorganic iron
Ferrous iron Fe2+
Ferric iron Fe3+
Acids :Hcl, vitamin C
Alkalis : antiacids , pancreatic secrtion
Sugar, aminoacids
Precipit. agents: phytate, phosphate
Iron deficiency
İron execess
pregnancy
Decreae erythropoiesis
eythropoisis
infection

tea

Main sites of absorbtion are; Duodenum, Upper jejunum

Transport of iron
Transferrin is the major protein responsible for transporting iron in the body, can bind two IRON atoms . It is produced in liver cells with increased synthesis in iron deficiency
Total iron binding capacity (TIBC): only 1/3 of transferrin saturated with iron
Plasma Transferrin : 300 μg/dL and Plasma Iron: 60-180 μg/dL

Causes of iron deficiencyETIOLOGY:

Chronic blood loss : Menorrhagia, GIT hemorrhagia, Bleeding disorder, Pulmonary lesions with bleeding, Hemodialysis, Hematuria (chronic), Frequent blood venisection and donation (250 mg iron /unit blood).
Increased demand : Pregnancy , Lactation, Rapid growth
Malabsorbtion of iron (diseae of absorbtion sites) .
Inadequate iron intake: Decreased iron in the diet, Vegetarianism
Pica

The steps of iron deficiency (developments):

Continued negative iron balance between intake , absorption and loss So cause : Depletion of iron stores….Reduction in plasma iron…….Reduction in Hb synthesis , hypochromia and , microcytosis………Anaemia

A. Pre-Latent IRON Deficiency: Decrease Storage bone marrow iron with normal Hb (no anaemia): but low serum ferritin, without reduction in serum iron & TIBC, with normal red cells morphology.
B. Latent anaemia: Absence of Storage Iron with normal Hb (No anaemia) bur decrease of Serum ferritin, Low iron and increase TIBC and increased transferrin, with normal red cells morphology.
C. Proper Iron deficiency Anemia (low Hb) with abnormal RBC morphology microcytic/hypochromic, with pencil shape.

Differential diagnosis of IRON deficiency anaemia : (other hypochromic):

a. Iron deficiency anemia
b. Thalassemia .
c. Sideroblastic anemia
d. Anemia of chronic diseases , late stages
e. Lead poisoning

Laboratory features of Iron Deficiency Anaemia and other hpochromic anaemia

Type of hypochromic anaemia
IDA
Thalassaemia
Chronic
diseases
Sideroblastic
MCV
low
low
N/R
Low.
MCH
low
low
= =
= =
S. iron
low
Norma/high
reduced
high
TIBC
raised
normal
reduced
normal
S. Transf. receptor
raised
variable
N/Low
normal
s. ferritin
low
Normal/high
N/ raised
raised
Bone stores
absent
present
present
present
erythroblast
absent
present
absent
Ring forms
Hb Electrophor.
normal
A2/F/ others
normal
normal

Laboratory diagnois of IDA ( Features):

A. Hematology:
1. Low Hb,Htc,RBC: MCV,MCH,MCHC:
2. Low Retics count.
3. Plt: High/ normal
4. WBC:Normal.
5. Smear (blood film): Hypochromia,anisocytosis,microcytosis, poikilocytosis, pencil cells.
B. Biochemical changes
1. Serum Iron: (Normal value : 60 – 180 μg/dL)
2. TIBC: (Normal value 250 - 430 μg/dL)
3. Serum Ferritin (N : Female;10-150 μg/L, Male;29-248 μg/L)
4. Transferrin saturation (Fe/TIBC normal > 15%): (<15% indicate IDA)
5. Serum Transferrin Receptor:

C. Bone marrow :

Erythroid hyperplasia, micronormoblastic maturation, with ragged cytoplasm absence of haemoglobin.

The diagnostic procedure is not complete until the underlying pathology is disclosed.

Good luck



رفعت المحاضرة من قبل: Hatem Saleh
المشاهدات: لقد قام عضو واحد فقط و 7 زوار بقراءة هذه المحاضرة






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