Flashcards in Anaemia and Polycythaemia Deck (42)
What can G6PD deficiency cause?
Intermittent, severe intravascular haemolysis as a result of infection or exposure to an exogenous oxidant
What tends to appear in blood films during these episodes of severe intravascular haemolysis?
Irregularly contracted cells
What happens to the haemoglobin during these episodes?
It becomes denatured and forms round inclusions called Heinz bodies
NOTE: you can get more than one Heinz body per cell unlike Howell-Jolly bodies
What causes acute haemolytic anaemia?
Results from the production of antibodies against red cell antigens
This is very sudden and dramatic
Describe how acute haemolytic anaemia can lead to spherocytosis.
The immunoglobulin bound to the red cell is recognised by splenic macrophages, which remove parts of the cell membrane leading to spherocytosis
State two causes of spherocytosis.
Autoimmune haemolytic anaemia
Describe the diagnosis of acute haemolytic anaemia.
Increased reticulocyte count
Detecting immunoglobulin on the red cell surface Detecting antibodies to red cell antigens or other antibodies in the plasma
What is the treatment for acute haemolytic anaemia?
Corticosteroids or other immunosuppressive agents Splenectomy in severe cases
Which red blood cell parameters are increased in polycythaemia?
What is the term given to a condition where these parameters are increased but the absolute amount of haemoglobin is not increased?
Pseudopolycythaemia (or apparent polycythaemia)
This is due to a decrease in plasma volume
State some causes of polycythaemia.
Elevation of EPO when at altitude
Tumour (renal or other tumour that can secrete high amounts of EPO)
Abnormal function of bone marrow – it can result from inappropriately increased erythropoiesis that is independent of EPO, this is an intrinsic bone marrow disorder called polycythaemia vera
It is a chronic myeloproliferative neoplasm