The Haemolytic Anemias Flashcards
Most hemoglobin degradation occurs in the
Macrophages of the spleen
Indirect indicators of erythrocyte destruction
Blood bilirubin
Urobilinogen concentration in the urine
Bilirubin is conjugated in the liver with
Glucoronic acid
Enzyme-Glucoronyl transferase
Haemolysis is associated with (bilirubin)
High concentrations of UNCONJUGATED BILIRUBIN
Evidence of increased haemolysis: Biochemical consequences
Hyberbilirubinemia(unconjugated)
Reduced serum haptoglobin
Evidence of increased haemolysis: intravascular haemolysis
Haemoglobinemia
Reduced serum haptoglobulin
Reduced serum hemopexin
Haemoglobinuria
Haemosiderinuria
Methalbuminemia (Schumm’s test)
Evidence of damaged red cells
Micro-spherocyte
Red cell fragments
Sickle cells
Evidence of increased red cell production
Polychromasia
Nucleated red cells
Clinical presentations of haemolysis
Jaundice
Anemia
Clinical features of haemolysis states
- Jaundice
- Pallor
- Pigment stones
- Splenomegaly
- Expansion of marrow cavities in congenital HA
Laboratory evidence of increased erythropoietic activity
- Reticulocytosis (polychromasia)
- Erythroblastaemia (nucleated rbcs)
- Macrocytosis (High MCV)
- Erythroid hyperplasia (Bone marrow)
- Reduced myeloid/erythroid ratio (Bone marrow)
- Changes in the skull and tubular bones
Evidence of red cell damage
Spherocytes
Fragment cells
Reticulocyte count is increased/decreased in hemolysis
Increased
Hemosiderinuria and Hemoglobinuria are present in
INTRAVASCULAR hemolysis
Complications of Hemolysis
- Aplastic crisis
- Leg ulcers; chronic haemolytic states
Diagnosis of hemolysis
- Demonstration of a hemolytic state
- Demonstration of its aetiology
Haemolytic states
Polychromasia +/- NRBC
Reticulocytosis
Erythroid hyperplasia
Treatment of haemolysis
Treat the underlying cause
Give folic acid
Red cell concentrates
Structure of the red cell membrane
Trilaminar
Outermost (glycolipids, glycoproteins)
Central (cholesterol, phospholipids)
Inner (cytoskeleton)
Most common congenital hemolytic anemia
Hereditary Spherocytosis
Inheritance is
Autosomal recessive/Autosomal dominant
Clinical features of Hereditary spherocytosis
Asymptomatic
Episodic jaundice
Variable splenomegaly
Gall stones
Laboratory features of hereditary spherocytosis
- Negative antiglobulin test
- Variable degree of spherocytosis
- Floe cytometric analysis for EMA binding to detect spherocytes
- Membrane protein defect test -
SDS-PAGE, RIA or EIA
Diagnosis of hereditary spherocytosis
Can be missed till adulthood
Molecular defect of Hereditary Spherocytosis
- RBC membrane loss is due to defective vertical protein linkage between membrane skeleton and lipid bilayer
- Caused by molecular defects in genes encoding for proteins (spectrin, ankyrin, band 3 and protein 4.2)
Molecular defect of hereditary Elliptocytosis
Most common defect is in soectrin
Clinical features of hereditary elliptocytosis
Asymptomatic
Anemia
No splenomegaly
Differentials of H.E
Iron deficiency
Artifacts
Myelodysplasia
Inheritance of G6PD deficiency
X linked, recessive (commoner in males)
Feature of G6PD Deficiency episodic haemolysis
Acute haemolysis induced by increased oxidant stress
G6PD Deficiency: Triggers of acute haemolysis
- Antimalarials, sulphonamides, nitrofurans
- Favism
- Infections
Clinical features of G6PD Deficiency
Acute haemolysis
Neonatal jaundice (most common cause)
Laboratory features of G6PD deficiency
Anisocytosis
Bite cells
Heinz bodies
Treatment of G6PD deficiency
- Stop precipitating drug or treat the infection
- Acute transfusions, if possible
Types of immune haemolytic anaemia
Autoimmune
Alloimmune
Types of autoimmune haemolytic anaemia
Warm IHA
Cold IHA
Drug induced IHA
Causes of Warm AI Haemolysis
50% Idiopathic
SECONDARY
1. Lymphoid neoplasm e.g CLL, Lymphoma, Myeloma
2. Solid tumors eg Lung, Kidney
3. Connective tissue ds e.g Lupus, RA
4. Drugs e.g Alpha methyl DOPA, Penicillin, Quinine, Chloroquine
5. Misc e.g UC, HIV
Types of CAHA
Cold agglutinin syndrome (CAD)
Paroxysmal cold hemoglobinuria
Causes of secondary CAD
Mycoplasma
Infectious mono
LPD
Causes of secondary Paroxysmal Cold Hemoglobinuria
Measles
Mumps
Syphilis
Who is affected by Warm AI Haemolysis
More females than males
All age groups
P smear of Warm AI Hemolysis
Micro-spherocytosis
Nucleated RBCs
Confirmation of Warm AI Haemolysis
Coombs test
Antiglobulin test
Treatment of Warm AI haemolysis
Correct underlying cause
1. Prednisolone
2. Transfusion; for severe occasions
3. Splenectomy (if steroids don’t work)
4. Immunosuppressives: Azathioprine, Cyclophosphamide
Clinical features of CAD
Acrocyanosis
IgM with specificity to I or IAg is seen in what disease
Cold AI Haemolysis
Examples of Mechanical trauma to red cells in Non immune HA
- Abnormalities to heart and large vessels
- Microangiopathic HA - HUS, TT, DIH
- March haemoglobinemia