haematology - inherited haemolytic anaemias Flashcards
inherited haemolytic anaemia membrane defects
hereditary spherocytosis
hereditary elliptocytosis
hereditary pyropoikilocytosis
pattern of inheritance of hereditary spherocytosis
autosomal dominant
hereditary spherocytosis deficiencies
membrane proteins
- spectrin
- ankyrin
hereditary spherocytosis is intra or extravascular?
extravascular
hereditary spherocytosis makes patients susceptible to
parvovirus B19
gallstones
hereditary elliptocytosis
autosomal dominant spectrin mutation leading to elliptical erythrocytes
hereditary pyropoikilocytosis
autosomal recessive
erythrocytes abnormally sensitive to heat
severity of hereditary elliptocytosis
ranges from hydrops foetal is to asymptomatic
inherited haemolytic anémia enzyme defects
G6PD deficiency
pyruvate kinase deficiency
role of G6PD
helps RBCs make glutathione for protection against oxidant damage
G6PD deficiency pattern of inheritance
X linked recessive
G6PD features which type of haemolysis
intravascular
features G6PD deficiency crisis
rapid anaemia jaundice dark urine bite cells Heinz bodies (blue deposits, oxidised Hb)
G6PD deficiency crisis triggers
oxidants drugs (2-3 days after starting) broad beans (<1 day of eating) acute stressors moth balls acute infection
drugs that may trigger G6PD deficiency crisis
primaquine
sulfonamides
aspirin
dx of G6PD deficiency made by
enzyme assay 2-3 months after crisis
take caution in G6PD enzyme assay because
young RBCs may have sufficient enzyme so results may appear normal
treatment of G6PD deficiency
avoid precipitants
transfusion if sever
genetic screening
splenectomy for chronic haemolysis
pyruvate kinase deficiency pattern of inheritance
autosomal recessive
autosomal dominant has been observed
features of pyruvate kinase deficiency
sever neonatal jaundice
splenomegaly
haemolytic anaemia
treatment of pyruvate kinase deficiency
most not required
blood transfusion
splenectomy
globin pairs and resulting type of haemoglobin
2 alpha + 2 beta = HbA
2 al[pha + 2 gamma = HbA2
2 alpha + 2 delta = HbF