Haemolytic anaemia Flashcards
What is the normal red cell life span?
120 days
- What is haemolysis?
- What are the two types?
- Haemolysis is defined as shortended red cell survival. May be predominantly:
- Intravascular - within circulation
- Extravascular - remova;/destructio by reticuloendothelial system
- Inherited for acquired
What are the 3 main causes of extravascular haemolytic anemia?
- Autoimmune
- Alloimmune
- Hereditary spherocytosis
What are some of the causes of intravascular haemolytic anaemia?
- Malaria
- G6PD deficiency
- Mismatched blood transfusion
- Cold antibody haemolytic syndromes
- Drugs
- Microangiopathic haemolytic anaemia (MAHA) e.g. HUS
- Thrombotic thrombocytopenic purpura
- Paroxysmal nocturnal haemoglobinuria
What form of inheritance is hereditary spherocytosis?
Autosomal dominant
What are the consequences of having haemolytic anaemia?
- Anaemia
- Erythroid hyperplasia with increased rate of red cell production and circulating reticulocytes
- Increased folate demand
- Susceptibility to effect of Parvovirus B19 (slap cheek)
- Propensity to gallstones
- Increased risk of iron overload and osteoporosis
What other syndrome when coinherited further increase risk of gallstones in chronic haemolytic anaemia?
Gilbert syndrome
UGT 1A1 TA7/TA7 genotype
What are the clinical features of chronic haemolytic anemia?
- Pallor
- Jaundice
- Splenomegaly
- Pigmenturia
- Family history
What are the possible laboratory findings in people with chronic haemolytic anemia?
- Anaemia
- Increased reticulocytes
- Polychromasia
- Hyperbilirubinaemia
- Increased LDH
- Reduced/absent haptoglobins
- Haemoglobinuria
- Haemosiderinuria - brown urine and a side effect of chronic intravascular haemolytic anemia
What are the two main red cell membrane disorders that can cause haemolytic anemia?
- Hereditary spherocytosis
- Hereditary elliptocytosis
What are the red cell membrane disorders in hereditary spherocytosis?
- Vertical interaction
- Band 3, protein 4.2, Ankyrin and/or Beta spectrin
What are the red cell membrane defects in hereditary elliptocytosis?
- Horizontal interaction
- Alpha spectrin
- Beta spectrin
- Protein 4.1
- What is hereditary spherocytosis?
- What is the mode of inheritance?
- Genetic defect of red cell cytoskeleton
- Autosomal dominant - 75% of cases
Red cells have an increased risk of lysis - osmotic fragility test
Reduced binding of dye eosin-5-maleimide
What does this image show?
Hereditary spherocytosis
What does this image show?
Hereditary elliptocytosis