FBC interpretation

Question 1

Where is thrombopoetin produced?

Answer 1

Liver

Question 2

What kind of infection/infections can cause neutropenia

Answer 2

Infection: viral, bacterial (e.g. Salmonella), protozoal (e.g. malaria)

Question 3

What kind of infection/infections can cause eosinophilia?

Answer 3

Infection: parasitic

Question 4

Is this true or false: Lymphopenia without any obvious cause is common with advancing age.

Answer 4

True

Question 5

Spontaneous bleeding does not usually occur until the platelet count falls below______, unless their function is also compromised

Answer 5

20 × 10(9)/L

Question 6

What drugs are specifically related to thrombocytopenia?

Answer 6

Drug-associated, especially quinine, vancomycin and heparin

Question 7

What is the underlying biological mechanism for porphyria?

Answer 7

Defects in haem synthesis cause the porphyrias

Extra: Haemoglobin is a protein specially adapted for oxygen transport. It is composed of four globin chains, each surrounding an iron-containing porphyrin pigment molecule termed haem.

Question 8

When patient has severe anaemia, what is the tranfusion target?

Answer 8

If no cardiovascular disease, transfuse to maintain Hb at 70 g/L
If known or likely to have cardiovascular disease, maintain Hb at 90 g/L

Question 9

What is the usual transfusion target for platelet?

Answer 9

Thrombocytopenia, e.g. in acute leukaemia, maintain platelet count > 10 × 10(9)/L if not bleeding
Maintain platelet count > 20 × 109/L if minor bleeding or at risk (sepsis, concurrent use of antibiotics, abnormal coagulation)
Increase platelet count > 50 × 109/L for minor invasive procedure (e.g. lumbar puncture, gastroscopy and biopsy, insertion of indwelling lines, liver biopsy, laparotomy) or in acute, major blood loss
Increase platelet count > 100 × 109/L for operations in critical sites such as brain or eyes

Question 10

How much does each platelet transfusion raise to platelet count?

Answer 10

Each adult dose has a minimum of 2.4 × 1011 platelets, which raises platelet count by 40 × 10(9)/L unless there is consumptive coagulopathy

Question 11

In polycythaemia rubra vera (PRV), a mutation in a kinase, _______, is found in over 90% of cases

Answer 11

JAK-2 V617F

Question 12

What are the common causes for raised Hb?

Answer 12

Absolute erythrocytosis

• polycythemia rubra vera
• hypoxia
• causes of inappropriate erythropoietin secretion e.g. use of Epo injection

Apparent erythrocytosis
The presence of hypertension, smoking, excess alcohol consumption and/or diuretic use is consistent with low-volume polycythaemia (Gaisböck’s syndrome)