Hemolytic Anemia Thalassemia Flashcards
The distinguishing feature of all hemolytic anaemia is?
The increased rate of red cells destruction
The breakdown od heam from red cells liberates what?
Iron —> recirculation via plasma transferrin to marrow erythroblasts
protoporphyrin —> which is broken down to biilrubin
Causes of Extravascular Haemolysis
Hemoglobinopathies
Hereditary spherocytois
Autoimmune hemolytic anemia
Malaria
G6PD deficiency
Causes of intravascular hemolysis
Mismatched ABO blood transfusion
Paraoxymal noctoral Hb
Malaria
G6PD deficiency
How would the bone marrow be affected by hemolytic anemia?
erythropoietic hyperplasia and anatomical extension of bone marrow
Heriditary hemolytic anemia are caused by?
intrinsic red cell defects
Aquired hemolytic anemia are caused by?
Extra corpuscular deffects
Paraoxymal noctural HBuria is an intinsic or extrinsic disorder?
Paroxysmal Nocturnal Hemoglobinuria is an acquired disorder but the PNH cells have an intrinsic defect
Labratory findings of Hemolytic anemia?
1- Features of Increased Haemoglobin Breakdown
i. Jaundice and Hyperbilirubenemia
ii. Reduced plasma Haptoglobin and Hemopixin
iii. Increased serum LDH
iv. Haemoglobinemia
v. Haemoglobinuria
vi. Met-hemoglobinemia
vii. Hemosidrinuria
2- Features of Increased Red cells Production (Compensatory Erythroid Hyperplasia)
i. Reticulocytosis
ii. Macrocytosis and Polychromasia
iii. Erythroid hyperplasia of marrow
iv. Radiological changes in bones (seen only in
congenital anaemia)
3. Feature of Damage to Red Cell
i. Spherocytes
ii. Increased red cells fragility
iii. Red blood cells fragmentation
Hemoglobin disorders result from?
- Reduced synthesis of normal Alpha or Beta globin chains
-Alpha Thalassaemia
- Beta Thalassaemia - Synthesis of an Abnormal Hemoglobin
- Crystaline Hemoglobin (HbS, C, D, E, O etc)
- Unstable Hemoglobin
Define Thalasemia
The Thalassaemias are a heterogeneous group of genetic disorders of haemoglobin synthesis all of which result from reduced rate of production or absence of production of one of the globin chains of haemoglobin
Unbalanced globin chain synthesis causes?
microcytosis, ineffective erythropoiesis and
hemolysis
—> Hemo tetramer form (insoluble)
—> percipated in RBCs
—> spleen macrophages will recognise it
—> RBCs hemolysis
—> ineffective erythropeises
In Beta thalassaemia what will happen regarding the synthesis of the globing chains?
the beta chain synthesis is decreased or absent but there will be unimpaired synthesis of Alpha chains
If No alpha missing normal CBC
If one alpha missing?
Two?
Three?
Four?
1 missing Normal CBC (asymptomatic)
2 missing Microcytosis, Minimal anemia
3 missing Microcytosis, hemolysis moderate to severe anemia (hemoglobin H disese)
4 missing fetal demise (lethal in utero) (hemoglobin barts)
What will happen if 1/2 betta globia re missing?
1 microcytosis, mild anemia
2 Transfusuion dependent anemia
Increasing globin chain imbalance causes?
ineffective erythropoiesis (precipitated α chains)
hemolysis (β tetramers or Hb H)
Worsening anemia
Beta thalassemia major
No beta chain produced/unimpared synthesis of Alpha
Homozygous state
Sever microcytic anemia
Marrow expansion
Iron overload
Growth failure and death
Beta thalssemia Minor trait
Homozygous state
Asymptomatic with mild or no anemia
red cell abnormalities seen
Defects in transcription, processing or translation of beta- globin m RNA
Clinical features of beta Thalassemia Major?
- Severe anemia with failure to thrive
- Enlargement of spleen occurs due to excessive red cells destruction, extra-medullary haemopoiesis and later because of iron overload. The
large spleen increases blood transfusion requirements due to increased pooling of blood. - Liver also increased in size
- Thalassaemic Facies and to thinning of the cortex of many bones with a tendency to fractures and bossing of the skull
- Infections induced by blood transfusion:
- Hepatitis B
- Hepatitis C
- Human Immunodeficiency Virus (HIV)
What’s the issue of contionious blood transfusion?
iron overload caused by repeated transfusions is inevitable unless chelation therapy
iron overload might affect different organs
(i) Liver: Cirrhosis Fibrosis) will take place
(ii) Endocrine Organs: failure of growth, delayed or absent puberty, diabetes mellitus,
hypothyroidism and hypoparathyroidism
(iii) Damage to Myocardium can lead to arrhythmias and cardiac failure.
The main cause of death if iron overload occured is?
cardiac damage is the main cause of death
Labratory diagnosis in Beta Thalasemia major
1- severe microcytic and hypochromic blood picture with marked pokilocytosis and anisocytosis
2- Reticulocytes count is increased
3- Peripheral blood shows normoblasts
Beta thalassemia major treatment
• Transfusion
•Iron chelation
•Stem cell transplant
