2. • Abnormally low:
• number of RBCs
• or level of hemoglobin,
• or both,
→ diminished oxygen-carrying capacity.
2
Definition
3. • Usually results from:
oexcessive loss (bleeding) or destruction (hemolysis) of RBCs
oor from deficient RBC production
➢lack of nutritional elements
➢or bone marrow failure.
3
Etiology
4. • not a disease,
• But indication of disease process.
4
Etiology
5. • Grouped into 3 categories:
1. Manifestations of impaired oxygen transport → compensatory
mechanisms
2. Reduction in red cell indices and hemoglobin levels
3. Signs and symptoms of the pathologic process causing anemia
5
Effects of Anemia
6. • Depend on:
• severity,
• rapidity of development,
• person’s age and health status.
6
manifestations of anemia
7. • Oxygen-carrying capacity of haemoglobin reduced
→ tissue hypoxia:
→ fatigue,
→weakness,
→dyspnea,
→sometimes angina.
7
manifestations of anemia
8. • Hypoxia of brain → headache, faintness, dim vision.
• Skin, mucous membranes → pallor.
• Heart: increase in cardiac output to compensate → Tachycardia and
palpitations.
• Ventricular hypertrophy and high-output heart failure in severe anemia.
• Erythropoiesis accelerated → bone pain.
• hemolytic anemias → increased blood levels of bilirubin → jaundice.
8
manifestations of anemia
9. • Laboratory tests: determining severity and cause of anemia.
• RBC count and haemoglobin levels → severity of anemia,
• RBC characteristics: size, color, shape → cause of anemia
9
manifestations of anemia
10. 10
Red cell characteristics in different types of anemia:
(A) microcytic and hypochromic red cells, iron deficiency anemia;
(B) macrocytic and misshaped red blood cells, megaloblastic anemia;
(C) abnormally shaped red blood cells in sickle cell disease;
(D) normocytic and normochromic red blood cells, as a comparison.
12. • group of inherited disorders of hemoglobin synthesis
→ decreased synthesis of α- or β-globin chains.
12
Hemoglobin molecule, showing the 4 iron (Fe)-containing heme subunits and their structure.
13. • β-Thalassemias deficient synthesis of β chain
• α-thalassemias deficient synthesis of α chain.
13
Classification
14. • defect is inherited.
• a person may be:
• heterozygous → mild form of the disease.
• homozygous → severe form of the disease.
14
Classification
15. • high frequency in certain populations.
1. β-thalassemias (Cooley’s anemia or Mediterranean anemia)
• High prevalence in Mediterranean region, Middle East, Southeast Asia.
• in Egypt: 1000/ 1.5 million live birth/year born with thalassemia.
2. α-thalassemias: most common among Asians.
15
Epidemiology
16. • Two factors contribute to anemia in thalassemia:
1. decreased synthesis of affected chain:
• → reduced synthesis of normal haemoglobin
• → hypochromic, microcytic anemia.
2. continued production of unaffected chain:
• → abnormal RBC
• → hemolysis → anemia.
16
Patophysiology
17. Etiology and pathophysiology:
• mutations in β -globin gene → defect in β-chain synthesis.
• excess α chains → precipitates in RBC → RBCs destroyed in bone
marrow and spleen.
• coagulation abnormalities.
17
β-Thalassemias
18. • Clinical manifestations:
• based on severity of anemia.
a) heterozygous persons (thalassemia minor):
• one normal gene
• → sufficient normal hemoglobin to prevent severe anemia.
18
β-Thalassemias
19. b) homozygous (thalassemia major):
• Severe anemia,
• blood transfusion–dependent
• evident at 6 to 9 months of age.
• If transfusion therapy not started → severe growth retardation.
19
β-Thalassemias
20. severe β-thalassemia:
• marked anemia → increased erythropoietin secretion →
• hyperplasia in bone marrow →
• impairs bone growth
• bone abnormalities.
• Osteoporosis → bone fracture.
• Enlargement of spleen (splenomegaly) and liver (hepatomegaly). 20
β-Thalassemias
21. • repeated transfusion and increased dietary absorption of iron
• → Iron overload:
• Iron deposited in heart, liver, endocrine organs → organ damage.
• Cardiac, hepatic, endocrine diseases.
21
β-Thalassemias
22. Treatment:
1. Regular blood transfusions: to maintain haemoglobin at 9-10 g/dL:
• improve growth and development and prevent most complications.
2. iron chelation therapy: reduce iron overload and extend life.
3. Stem cell transplantation: potential cure for younger people with no
complications, has excellent results.
22
β-Thalassemias
