1. Specific treatment of the causes e.g. as Ancylostoma, or cow- milk protein allergy etc.
2. Oral iron therapy: The best is ferrous sulphate in a dose of 6 mg/kg/day of elemental iron (=30 mg/kg/day ferrous sulphate), in 3 divided doses.
Better absorption occurs if given between meals (on empty stomach). It is given for 4-6 weeks after correction of hematological values.
3. Parenteral iron therapy: Iron dextran complex (Imferon). It is not superior to oral iron administration (50 mg iron/ml).
Calculation of the dose
(Normal Hb-initial Hb) X 1/100 X blood volume (ml) X3.4 X 1.5 Blood volume= 80 ml/kg body wt
3.4 is the amount of iron (mg) in one gram Hb.
1.5 provides extra-iron to replenish iron stores.
4. Packed RBCs: Are given only if there is severe anemia or in presence of infection which may interfere with hematologic response.
If anemic heart failure; a modified exchange transfusion using fresh packed RBCs +/- Fursemide are used.
5. Following correction of anemia, an adequate diet should be instituted.
A hemorrhage response in the form of reticulocytosis is evidence after 48-72 hours from start of iron therapy. The treatment should continue for 3 months to replenish iron stores.
The Expected effect of Iron Therapy
1. Within the first day: Repletion of intracellular iron containing enzymes which leads to increase appetite and improved irritability.
2. Within the first 2 days; bone marrow shows erythroid hyperplasia.
3. At the 3rd day, reticulocytosis appears in peripheral blood, which peak, about the 6th day.
4. From fourth to 30th day; gradual increase of Hb level.
5. From 1-3 months gradual repletion of body iron stores.
Anemia Refractory to Oral Iron 1. Medication
a. Poor preparation (e.g expired drugs) b. Drug interaction
2. Patient
a. Poor compliance b. Bleeding continues c. Malabsorption (rare) 3. Physcian
a. Misdiagnosis b. Consider also:
Anemia of chronic disease
Thalassemia (minor)
Sideroblastic anemia
IV Fe
Figure 3.1: Iron deficiency anemia: The RBC’s are smaller than normal and have an increased zone of central pallor. This is indicative of a hypochromic microcytic anemia. There is increased anisocytosis and poikilocytosis.
OTHER CAUSES OF HYPOCHROMIC ANEMIA CHRONIC LEAD POISONING
It is a hypochromic microcytic anemia, with coarse basophilic stippling of RBCs.
Diagnosed by increased of free erythrocyte protoporphyrin (FEP) more than 150mg/dl of blood and urinary excretion of large amounts of corporphirin in urine.
Other manifestations of chronic lead poisoning are usually present as:
Acute abdominal colic associated with constipation, acute lead encephalopathy; with vomiting, ataxia impaired consciousness, convulsions and coma. Peripheral neuropathy (motor) is less common in children than adults.
SIDEROBLASTIC ANEMIAS
These are hypochromic microcytic anemia, caused by defects in iron or heme metabolism. There is elevated serum iron. The bone marrow contains sideroblasts, which are nucleated red blood cells with a perinuclear collar of coarse hemosiderin granules that represent iron-laden mitochondria.
A. X-linked type usually presents in late childhood (splenomegaly is usually present).
B. Vitamin B responsive anemia. Responds to large doses of vitamin B6 (200-500 mg/day)
ANEMIA OF CHRONIC DISEASE
It is seen in patients with infection, cancer, liver disease, inflammatory and rheumatoid disease, renal disease and endocrine disorders (thyroid).
Pathophysiology
A mild hemolytic component is often present. Red blood cell survival modestly decreased.
Erythropoietin levels are normal or slightly elevated but are inappropriately low for the degree of anemia. Erythropoietin level is low in renal failure.
Iron cannot be removed from its storage pool in hepatocytes and reticuloendothelial cells.
Laboratory Features
Usually anemia is mild normocytic and normochromic. It may be microcytic and normochromic if the anemia is moderate. May be microcytic and hypochromic if the anemia is severe but rarely <90 g/L.
Bone marrow shows normal or increased iron stores but decreases
―normal‖ sideroblasts.
Iron Indices
Serum iron is normal or slightly reduced. Total iron binding capacity (transferrin) is normal or slightly reduced. Percent saturation is normal or slightly reduced.
Serum ferritin is normal or increased
Treatment
Treat the underlying disease. Erythropoietin may normalize the hemoglobin value
Dose of erythropoietin required is lower for patients with renal disease Only treat patients who can benefit from a higher hemoglobin level.
REVIEW QUESTIONS
1. What is the primary function of iron
a. Molecular stability
b. Oxygen transport
c. Cellular metabolism
d. Cofactor
2. Which of the following influences iron absorption?
a. Amount and type of iron in food b. Function of GI mucosa and pancreas c. Erythropoiesis needs and iron stores
d. All of the above
3. What is the correct sequence for iron transport?
a. Ingestion, conversion to ferrous state in stomach
reconversion to ferric state in blood stream, transport by transferring, incorporation into cells and tissues
b. Ingestion, transport by transferring to cells and tissues, conversion to ferrous state prior to incorporation into cells and tissues.
c. A and B are correct
d. Non of them
4. In iron deficiency anemia there is characteristically
a. An atrophic gastritis
b. A low mean corpuscular volume
c. A reduced total iron binding capacity d. Megaloblastic changes in the bone marrow
5. What are the two major categories of iron deficiency?
a. Defect in globin synthesis and iron incorporation b. Low availability and increased loss of iron c. Defective RBC catabolism and recovery of iron d. Problems with transport and storage of iron
6. Which are characteristic laboratory findings(s) for IDA?
a. Increased RDW
b. Decreased MCV, MCH, MCHC
c. Ovalocytes, elliptocytes, microcytes
d. All of the above
7. Which laboratory test results would be most helpful in distinguishing
IDA from anemia of chronic disease?
a. Decreased MCV, MCH, marked poikilocytosis
b. Increased MCV, MCH, MCHC, decreased RDW
c. Increased RDW and TIBC
d. Decreased RDW and TIBC
8. What term refers to the accumulation of excess iron in macrophages?
a. Sideroblastic anemia
b. Hemosiderosis
c. Porphyria
d. Thalassemia
9. Which of the following would not be seen in sideroblastic conditions?
a. Increased RDW
b. Pappenheimer bodies
c. Ringed sideroblasts
d. Decreased serum iron
10. What is the characteristic finding in lead poisoning?
a. Basophilic stippling
b. Target cells
c. Sideroblasts
d. Spherocytes
11. The following statements are correct about the expected effect of iron therapy except:
a. Within the first 2 days; bone marrow shows erythroid hyperplasia.
b. At the 3rd day, Reticulocytosis appears in peripheral blood, which peak, about the 6th day.
c. From fourth to 30th day; gradual increase of Hb level.
d. From 1-3 weeks gradual repletion of body iron stores.
12. The following statement concern iron deficiency anemia except
a. stage I :is stage of depletion of iron store b. stage II: impaired erythropoiesis
c. stage III: stage of anemia with marked appearing of microcytic RBCs and pathologic indices d. stage IV: The most significant finding is the classic microcytic hypochromic anemia