Red Cells Flashcards
What is anaemia?
Reduction in red cells or their haemoglobin content
What substances are required for red cell production?
Iron, copper, cobalt, manganese
B12, folic acid, thiamine
Amino acids
Erythropoietin, androgens, thyroxine, SCF
What is the typically lifespan of red blood cells?
120 days
What are red blood cells broken down into?
Globin
Haem > bilirubin
What is the function of skeletal proteins?
Maintain red cell shape and deformability
What can occur if there are skeletal protein defects?
Increased cell destruction
What structural proteins are defected in hereditary spherocytosis?
Ankyrin Alpha Spectrin Beta Spectrin Band 3 Protein 4.2
What is the clinical presentation of hereditary spherocytosis?
Anaemia
Jaundice (neonatal)
Splenomegaly
Pigment gallstones
What is the treatment for hereditary spherocytosis?
Folic acid
Transfusion
Splenectomy
What is the function of the pentose phosphate shunt?
Protects from oxidative damage
What is the function of glucose 6 phosphate dehydrogenase?
Protects red cell proteins from oxidative damage
If G6PD deficiency is X linked, who is affected?
Affects males
Female carriers
What is the clinical presentation of G6PD deficiency?
Neonatal jaundice
Drug, broad bean or infection precipitated jaundice or anaemia
Splenomegaly
Pigment gallstones
What drugs can cause G6PD deficiency?
Antimalarials Sulphonamides and sulphones Antibacterials Analgesics Antihelminthics Vitamin K analogues
What occurs in pyruvate kinase deficiency?
Reduced ATP
Increased 2,3-DPG
Cells rigid
What is the clinical presentation of pyruvate kinase deficiency?
Anaemia
Jaundice
Gallstones
What is the basic function of haemoglobin?
Oxygen to tissues
Carbon dioxide to lungs
What is the composition of haemoglobin?
Haem molecule
2 alpha chains
2 beta chains
What is the composition of sickle haemoglobin?
Haem molecule
2 alpha chains
2 beta (sickle) chains
What are the consequences of HbS polymerisation?
Haemolysis, endothelial activation, promotion of inflammation, coagulation activation, vaso occlusion
What are the complications of sickle cell disease?
Acute chest syndrome
Stroke
Pain episodes attributed to vasoocclusive tissue damage
What is the clinical presentation of sickle cell disease?
Painful bone and chest vaso-occlusive crises
Stroke
Hyposplenism
Chronic haemolytic anaemia (gallstones, aplastic crises)
Spleen and liver sequestration crises
What is the management of a chest crises?
Respiratory support Antibiotics IV fluids Analgesia Transfusion
What is the clinical presentation of chest crises?
Chest pain
Fever
Worsening hypoxia
Infiltrates on CXR
What is the life long prophylaxis for sickle cell disease?
Vaccination
Penicillin (and malarial) prophylaxis
Folic acid