ANEMIA

Definition:
Reduction of the red cell mass due to a lowering in the Hb, conc. and or the RBC count below
the normal for age & sex.
Classification
According to the morphological feature and red cell indices: ">I- Microcytic,Hypo chromic (MCV<>
1. Iron deficiency.
2. Thalassemia.
3. Sideroblastic anemia.
4. Anemia of chronic diseases
II -Normocytic,Normochromic( MCV:85 - 97fl,MCH 28 - 34pg).
· A plastic anemia.
· Acute hemorrhage
· Hemolytic anemia.
III- Macrocytic Anemia (MCV> 100fl).
· Megaloblastic anemia
· Non megaloblastic anemia.
· Liver disease
· Acute hemolysis.
· Acute blood loss
· Hypothyroidism.

Iron deficiency anemia

Basic metabolic features:
· Sources: red meat, liver, vegetables.
Mainly ferric.
Daily minimum requirements 12 mg
· Absorption:
Preliminary reduction into ferrous in the stomach.
Absorbed in the duodenum.
· Transport:
Attached to the protein transferrin.
· Utilization:
Incorporation into hemoglobin, myoglobin, enzymes, (cytochromes, catalases, peroxidases)
· Storage:
Tissue
iron stores : about 1gm .
Sites:
liver, bone marrow, spleen, muscles.
Forms
:
Ferritin: protein (apoferritin) shell surrounding a crystalline core of ferric oxidephosphate.
Iron can be mobilized from this molecule for erythropoiesis.

Causes of iron deficiency

Iron imbalance when requirements outstrip the available iron because of:
1Inadequate dietary intake.
2Failure of absorption.
3Excessive iron loss particularly chronic blood loss (commonest cause).

Pathogenesis:
· As the availability of iron stores becomes critical erythropoiesis becomes
abnormal, resulting in:
1Reduction in red cell size.
2Reduction in Hb, conc in the RBCs.
3Fall in Hb level & PCV in the blood
· With established iron deficiency, tissue changes may occur.
Laboratory diagnosis:
1Hemogram:
· Anemia typically microcytic, hypochromic (decreased MCV, MCH& MCHC).
· Increased red cell distribution width (RDW).
· Blood film: hypochromia, microcytosis, anisocytosis, poikilocytosis, pencil
RBCs, target cells.
· WBCs & platelet: variable.



2Bone marrow exam:
· Erythroid hyperplasia
· Absent iron stores.
3Iron studies:
· Decreased serum iron.
· Low % saturation.
· Increased total iron binding capacity ( TIBC).
4Serum ferritin :
· Low, generally reflects the mobilisable iron stores& more sensitive than serum iron&
TIBC.
· May be falsely raised e.g. Malignancy or chronic disease.
5Increased erythrocyte free protoporphyrin.

Assessment of response to treatment:
1HB: rise by 0.1 to 0.2 g/dl/day.
2Reticulocytic count: rises 5-11 days of treatment.