haematology: blood test interpretation

Question 1

What does is purple top blood tube indications

Answer 1

FBC, reticulocyte count, COOMBS, malaria testing
Contains EDTA (anticoagulant binds Ca that prevent blood clotting)

Question 2

What is the four initial laboratory test

Answer 2

1. FBC: cytopenia, classify anemia & increased counts
2. Differential count: underlying disease clues
3. Smear review: morphological features
4. Reticulocyte count: indication of effectiveness of red cell production

Question 3

What does is blue top blood tube indications

Answer 3

INR, PTT, clotting factor
Trisodium citrate (anticoagulant binds Ca but reversible)

Question 4

What does the pink top blood tube indications

Answer 4

Special blood grouping tubes

Question 5

What is the biochemical of polycythaemia

Answer 5

Elevated RCC, Hb & Hct

Question 6

What is four causes of polycythaemia

Answer 6

1. Congenital
2. Hypoxia
3. Renal disease
4. Heavy smoking
5. Polycythemia vera
6. Methemoglobinemia
7. Apparent polycythemia

Question 7

What is the differential count

Answer 7

Different types of white cells making up white cell count

Question 8

What is the percentage count & absolute count

Answer 8

Percentage count: relative proportion of different white cell types
Absolute count: how many cells of each white cell type there is

Question 9

Why is the differential count used

Answer 9

Useful as body’s response to different infections & disease is reflected by changes in proportion/number of different white blood cells

Question 10

What is the two types of analyses for differential count

Answer 10

Automated: count thousands of cells in sample but inaccurate if abnormality in blood
Manual: small number of cells counted & accurate

Question 11

What is the five types of leukocytes & their function

Answer 11

1. Neutrophils & monocytes: phagocytose & kill organisms/dead host cells
2. Eosinophils: allergenic response & parasite killing
3. Basophils: hypersensitivity reaction & anti-parasitic functions
4. Lymphocytes: antibodies, cell mediated immunity & regulation of immune response

Question 12

What is the three main causes of thrombocytopenia with examples

Answer 12

1. Decreased production: drugs & viral infections
2. Increased consumption: DIC, TTP, HUS, HELLP, autoimmune, alloimmune
3. Pseudo thrombocytopenia

Question 13

What is the two main causes of thrombocytosis with examples

Answer 13

1. Primary: inherited or acquired
2. Secondary: acute infection/inflammation, bleeding, malignant disease, surgery, iron deficiency & splenomegaly

Question 14

What cells are visible in peripheral blood smear

Answer 14

RBC, WBC, platelets

Question 15

What is the normal amount of lobes in a neutrophil

Answer 15

3-5 lobes

Question 16

What is the appearance of the chromatin & cytoplasm of the neutrophil

Answer 16

Chromatin: clumped
Cytoplasm: pink with fine purple granules

Question 17

Where does the maturation of a neutrophil occur & what cells are seen in peripheral blood

Answer 17

In bone marrow
Some band cells & neutrophils

Question 18

What is reactive changes of neutrophils

Answer 18

Toxic granules, phagocytosis & vacuolation

Question 19

What is a left shift of neutrophils

Answer 19

Presence of granulitic precursor in peripheral blood

Question 20

What is a right shift of neutrophils

Answer 20

Increase in number of nuclear lobes

Question 21

What causes pseudo thrombocytopenia

Answer 21

Platelet clumping

Question 22

What is pancytopenia

Answer 22

Anemia, neutropenia & thrombocytopenia

Question 23

What is four causes of pancytopenia

Answer 23

1. Defects in stem cells
2. Ineffective haemopoiesis
3. Replacement of bone marrow by an infiltrate
4. Peripheral cause