anaemia Flashcards
What is high unconjugated bilirubin usually due to?
Pre-hepatic causes because bilirubin is metabolised in the liver.
High in haemolysis (breakdown of RBC)
What are spherocytes and their features?
Round RBC lacking central pallor (very pigmented centre). Have shorter life span
What is hereditary spherocytosis and what does it cause? What is it due to?
Inherited defect in RBC membrane so it cant hold normal shape & becomes rounded.
Disruption of vertical linkages usually ankyrin/spectrin
Why do we see polychromatic macrocytes & reticulocytes in spherocytosis?
Bone marrow trying to produce more of these cells to compensate for reduced Hb
What do you do for the mild phenotype of hereditary spherocytosis and the severe type?
Mild phenotype give folic acid + annual assessment. Severe phenotype give splenectomy to increase red blood life span
What does hereditary spherocytosis predispose to and why? What can this cause?
Predisposes to gallstones due to high bilirubin. Can get obstructed common bile duct and pigment stones leading to high conjugated bilirubin later on
What is difference between haemolysis and haemolytic anaemia?
Haemolysis is pathological process where RBC have shortened life. Haemolytic anaemia is when haemolysis leads to anaemia
What is the key diagnostic for hereditary spherocytosis?
Family history
What does a slightly increased MCV indicated vs a significantly elevated MCV?
Slightly elevated MCV - megaloblasts or reticulocytes. Significantly elevated MCV- megaloblasts
When do you get reduced haptoglobins?
In haemolysis. Means that blood cells are getting destroyed more quickly
What is the direct antiglobulin test DAT and when is it used?
DAT test detects antibody bound to RBC, to see cause of haemolysis
what does positive direct antiglobulin test DAT point to?
auto-immune haemolytic anaemia AIHA
What is auto-immune haemolytic anaemia (DAT positive)? What is it associated with?
AIHA is idiopathic. Associated with disorders of the immune system eg SLE, underlying lymphoid cancers (lymphoma)
What can inherited defects of RBC cause?
Membrane defect, abnormal haemoglobin (sickle cell, thalassaemia), defect in glycolytic pathway (eg pyruvate kinase deficiency), defect in enzyme of pentose shunt (GDPD deficiency)
What does the glycolytic pathway do?
Provides energy for the cell
What does the pentose shunt do and what enzyme does it use?
Protects from oxidant damage using enzyme G6PD (glucose-6-phosphate dehydrogenase)
What are irregularly contracted cells?
RBC with irregular borders lacking central pallor. Oxidant damage
What are hemighost cells and what do they show?
RBC pushed to one side and other side pale, intravascular haemolysis
What are ghost cells & what do they mean?
Very faint RBC cant see much Hb. Intravascular haemolysis