Common causes of anaemia and thrombocytopenia

Question 1

Causes of anaemia

Answer 1

• Blood loss
• Haematinic deficiencies
• Secondary to chronic disease
• Haemolysis
• Alcohol, drugs, toxins, renal impairment

Question 2

Classification of anaemia

Answer 2

• Macrocytic – High Mean cell volume, Big RBC - B12 / folate deficiency
• Normocytic – Normal MCV
  Anaemia of chronic disease
• Microcytic – Low MCV, small RBC
  Iron deficiency, haemoglobin disorders (thalassaemia)

Question 3

Iron deficiency anaemia – microcytic anaemia

Answer 3

• Most common cause of anaemia

- Body can’t excrete iron so regulates it by limited absorption

Question 4

Treatment of iron deficiency anaemia

Answer 4

• Cause is more important than treatment
• Establish low iron through FBC, MCV and film
• Establish cause - based on type of patient
• Iron therapy - IV the only route commonly used

Question 5

Megaloblastic anaemia

Answer 5

• RBC bigger, MCV high, lobed nuclei
• B12/folate deficiency most common cause - DNA starved of bases
• Treatment - B12 and folate until B12 deficiency excluded - cannot give folate without B12 unless proven folate deficient
• Folic acid 5mg orally daily to build stores; need potassium and iron initially

Question 6

Diagnosis of B12 and folate deficiency

Answer 6

• Bilirubin and LDH - haemolysis
• B12 and folate levels
• Antibodies - B12 deficiency often autoimmune

Question 7

Haemolysis

Answer 7

• shortened red cell life
• Caused by intracellular Haemoglobinopathy and enzyme defects
• Caused by membranous hereditary spherocytosis

Question 8

Investigations for haemolysis

Answer 8

• Anaemia
• Blood film - spherocytes show up
• Raised bilirubin, LDH - markers of RBC breakdown
• Low haptoglobins
• Urinary haemosiderin

Question 9

Anaemia of Chronic Disease/Inflammation

Answer 9

• A normocytic anaemia
• Suppression of normal BM function and release of iron
• Typically normocytic = normal ,MCV
• Reduced RC production , release of inflammatory cytokines in particular hepcidin - inhibits release of iron

Question 10

Diagnosis of Anaemia of Chronic Disease/Inflammation

Answer 10

• often raised inflammatory markers
• Normal/high ferritin but low serum iron
• Normal % saturation of transferrin

Question 11

What is thrombocytopenia

Answer 11

Decrease in the number of platelets - asymptomatic until severe

Question 12

Common causes of thrombocytopenia

Answer 12

• Drugs, alcohol, toxins
• ITP (immune thrombocytopenic purpura)
• Liver disease and/or hypersplenism
• Pregnancy
• Haematological/marrow disease
• Infections – acute or chronic
  Acute sepsis/ HIV/ EBV/ etc
• DIC

Question 13

Presentation of thrombocytopenia

Answer 13

• Bruising/petechiae

- Low platelet count - Below 30 requires treatment

Question 14

Therapy of thrombocytopenia

Answer 14

• Steroids IV

- New thrombomimetics - eltrombopag

Question 15

ITP (immune thrombocytopenia purpura)

Answer 15

• Antibody mediated platelet destruction
• Presents with bruising, platelet count <10 is urgent
• Treated again with steroids as first line - followed by Immunosppresives or thrombo-mimetics

Question 16

TTP (thrombotic thrombocytopenia purpura)

Answer 16

• Abnormality in proteins such as vWF that cause lots of little thrombosis in the vasculature = damage to RBC membrane
• Usually present unwell with fever
• Therapy = plasma exchange - DO NOT GIVE PLATELETS