Download IRON DEFICIENCY ANEMIA

IRON DEFICIENCY ANEMIA
• ERYTHROPOIESIS : * erythropoietin
* normal BM
* iron
IRON – used for synthesis of HEMOGLOBIN
by addition of iron to porphyrin in the
mitochondria of erythrocyte precursor
- almost all iron required for Red cell
prodxn is acquired thru recycling of iron
extracted from senescnt RBC
IDA
• Maximal Iron Absorption – DUODENUM
& UPPER JEJUNUM – where acidic
gastric juices reduces insoluble FERRIC
IRON to its soluble FERROUS state
• Iron Absorption Regulation – Cytoplasmic
iron concentrate in mucosal cells
IDA
• Measurement of Iron Supply:
1. Serum Iron- amount of iron bound to
transferrin
2. TIBC- measure of total binding capacity
of transferrin. Decrease iron = inc TIBC
3. Serum ferritin – Iron + apoferritin –
protein which binds to free ferrous iron
4. Marrow iron stores
IDA
• IRON Transport:
1. Pinocytosis
2. Transferrin – principal means of moving iron
IRON Storage:
1. Ferritin – enclosed in a shell composed of a
protein (apoferritin)
2. Hemosiderin – aggregates of ferritin
molecules thar have been stripped of apoferritin
Factors that Influence Iron
Absorption
•
•
•
•
•
•
•
•
•
INCREASE
Acids
HCl
Vit C
Inorganic Iron
Ferrous Iron
Iron deficiency
Increased demand
Primary
Hemochromatosis
•
•
•
•
•
•
•
•
•
DECREASE
Alkalis
Antacids
Pancreatic secretions
Organic Iron
Ferric Iron
Excess Iron
Decreased Utilization
Infection/Inflamation
Major Causes of IDA
1. Chronic blood loss – most
common
• 2. Increased Iron Requirement
• 3. Iron Malabsorption
• 4. Inadequate dietary iron intake
Stages of IDA
• I. Storage Iron Depletion
iron reserves are lost w/o compromise of the
iron supply for erythropoiesis
BM aspirate- decrease/absent iron stain
decrease level of serun ferritin
II. Iron Deficient Erythropoiesis
erythroid iron supply is reduced w/o
development of anemia
RBC- microcytic, hypochromic
increase TIBC
III. Iron Deficiency Anemia
severe hypochromic and microcytic RBC
Clinical Mx of IDA
• Non specific – fatigue, weakness
• Signs – pallor, tachycardia, unexplained
retinal hemorrhages and splenomegaly
• Atrophic changes in epithelium:
a. oral lesion, angular cheilosis,
glossitis, stomatitis
b. dysphagia
c. koilonychia
d. pica
Parenteral Iron Therapy
• 1. Cannot tolerate the side effects of oral
therapy
• 2. Suffers from inflammatory bowel
dss/peptic ulcer
• 3. Does not comply with prescribed dosages
• 4. Displays documented iron malabsorption
• 5. Suffer from a condition such as
hereditary hemorrhagic telangiectasia
Management of IDA
• FeSo4 – 50 mg elemental iron/ 325 mg tab
• Ferrous gluconate/fumarate – better
tolerated
Reticulocytosis – 3-4 days after initiation of
iron therapy
Replacement Therapy
• No Response:
1. Incorrect diagnosis
2. Continued loss of iron
3. Chronic infection/inflammation
4. Lack of patient compliance
5. Ineffective release of iron
6. Malabsorption of iron
ANEMIA OF CHRONIC DISEASE
• Mechanism of Action
1. Relative Iron Deficiency:
a. Apolactoferrin – iron binding protein
released into the bloodstream by phagocytes
in response to inflammation, strips iron
from transferrin and return it to
mononuclear phagocytes w/c reconverts
iron to ferritin and hemosiderin
ANEMIA OF CHRONIC DSS
b. Interleuken-1 – released by monocytes
and macrophages. Stimulates increased
retention of iron by macrophages to limit
amount of iron for bacterial growth, limiting
also iron for erythropoiesis
2. Shortened life span – 60-90 days
3. Relative marrow failure – low EPO levels/
ability of erythroid precursor to respond to
EPO is impaired (BFU-E)
ANEMIA OF CHRONIC DSS
• Etiology : 1-2 months of sustained dss
1. Chronic ifection/inflammatory dss.:
TB, Pneumonia, osteomyelitis,
bacterial endocarditis
2. Chronic non infectious inflammatory
dss: sarcoidosis,SLE, RA
3. Malignancies – CA, lymphoma,
sarcoma
Anemia of Chronic Dss
Clinical Mx.: normocytic, normochromic
Hct- 25-35% ; normal WBC/PC
usually asymptomatic
DIAGNOSIS:
1. Chronic inflammatory dss/malignancy
2. Low/normal level of serum iron asso with
decrease TIBC and transferrin saturation
3. Normal/incrse serum ferritin
4. Abundant hemosiderin
Anemia of Chronic Dss
• Treatment:
* Treat underlying cause
* EPO therapy : 100-150 u/kg EPO TIW,
SC or IV
* Iron is contraindicated