RBC Metabolic Disorders Flashcards
Give two RBC metabolic disorders
G6PD deficiency
Pyruvate deficiency
What is the most common RBC metabolic disorder?
G6PD deficiency
What does G6PD do?
Oxidizes G6P to 6-phosphoglycerate and reduced NADP to NADPH allowing for control of reactive O2 species
What does G6PD deficiency often cause?
Haemolytic anaemia
Describe G6PD deficiency
More common in males.
Over 400 variants- A+ and B+ most common/normal. Reduced activity most common: A- and Mediterranean.
Give the two most common pathological forms of G6PD deficiency
A-
Mediterranean
What are the symptoms of A- G6PD deficiency
Mild
Self limiting haemolysis- New cells are almost normal
What cells are affected in A- G6PD deficiency?
Old RBC
Young normal
What cells are affected in Mediterranean G6PD deficiency?
New and old RBC
Describe the pathology of Mediterranean G6PD deficiency
Hb levels fall after oxidative shock
What can trigger Mediterranean G6PD deficiency symptoms
Fava beans
Drugs- Aspirin, quinene
Moth balls- Naphthalene
Infection
What are the symptoms of Mediterranean G6PD deficiency
Haemolysis
Prolonged neonatal jaundice
Acute kidney failure
How do you diagnose a G6PD deficiency?
Blood count is normal between attacks During attack: -Haemolysis is present -Irregularly contracted cells -Bite cells -Heinz bodies -Reticulocytosis Cells with G6PD can't reduce dyes Assey for enzyme level
What are some issues when diagnosing a G6PD deficiency?
May be normal directly after test as old damaged cells removed.
Varies in females due to selectively inactive chromosome.
How do you treat a G6PD deficiency?
Stop offending drugs
Treat underlying infection
Blood transfusion may be life-saving
Splenectomy is not usually helpful
