Hematological tests

1. ROUTINE HEMATOLOGICAL
LABORATORY TESTS
DRCALEBOKOTH
Uzima universitycollege

2. HEMATOLOGICAL TESTS
• Offers several tests relevant to anemia
diagnosis
• The more routine tests such as the CBC and
reticulocyte count as well as studies of iron
supply that serve both as screening tests and a
jumping-off point to diagnosis
• These measurements are provided by any of
the common automated counters.

3. COMPLETE BLOOD COUNT
• Also called full hemogram (FHG), full bllod
count (FBC)
• Test that evaluate the cells that circulate in
blood
• Test used to determine general health status,
screen, diagnose or monitor any
disease/conditions that affect blood cells e.g.
anemia, infection, inflammation, bleeding
disorder or cancer.

4. COMPLETE BLOOD COUNT
• The CBC includes determinations of the following:
1. White blood cell count
2. Platelet count
3. Evaluation of red blood cells
 Red blood cell count
 Hemoglobin
 Hematocrit
 Red blood cell indices :
 Red blood cell volume/Mean copurscular volume
 Mean cell hemoglobin (MCH)
 Mean cell hemoglobin concentration (MCHC),
 Red blood cell distribution width (RDW)

5. Complete blood count
White blood cells
• Evaluate WBC count
• Five types of WBC: neutrophils, lymphocytes,
basophils, eosinophils and monocytes.
• Are present at blood in relatively stable
numbers
• Numbers shift higher or lower depending on
what is going on in the body e.g. neutrophil
count increases in bacterial infections.

6. WBC related details
• Neutrophils (raised in leukaemia, inflammation,
infection)
• Lymphocytes ( raised in Lymphoma, viral
infection)
• Monocytosis?
• Eosinophils (raised in allergy, worms)
• % is easy to see in a report but use absolute
numbers for proper assessment

7. White blood cell count
• Most infections result in leucocytosis— as a
normal response to an infection
• Leucocytopaenia in the presence of an
infection indicates an abnormal response and
hence poor prognosis.

8. Complete blood count
Total red blood cells
• The number of red cells is given as absolute
number per litre. In iron deficiency anaemia RBC
count is low
Hemoglobin
• The number of hemoglobin (Hb) in the blood,
expressed in grams per decilitre (g/dL )
Hematocrit (packed cell volume)
• Is the fraction/proportion of whole blood volume
that consists of red blood cells

9. Red cell indices
• Are typically calculated from other measured RBC
parameters
• They include: MCV, MCHC, MCH and RDW
MEAN CELL VOLUME (MEAN CORPUSCULAR
VOLUME), MCV
• It is the average volume of red cells measured in
femtolitres
• The normal MCV is 90 ± 9 fL .
• The MCV accurately detects any general increase
(macrocytosis) or decrease (microcytosis) in red blood
cell volume

10. Red cell indices
MEAN CELL (CORPUSCULAR) HEMOGLOBIN, MCH
• It is the average amount of hemoglobin per red blood
cell, in picograms
• The automated counter provides a calculated mean cell
hemoglobin (ie, the hemoglobin level divided by the
red blood cell count).
• The normal MCH is 32 ± 2 pg.
• This is an excellent measure of the amount of
hemoglobin in each individual red blood cell.
• Patients with iron deficiency or thalassemia who are
unable to synthesize normal amounts of hemoglobin
show significant reductions in the MCH

11. Red cell indices
MEAN CORPUSCULAR HEMOGLOBIN
CONCENTRATION, MCHC
• It is the average concentration of hemoglobin
in red blood cells
• In hypochromic anemia, such as caused by an
iron deficiency, the MCHC is decreased.
• The normal value of the MCHC is 33 ± 3%.

12. Red cell indices
RED CELL DISTRIBUTION WIDTH (RDW)
• Automated counters provide measurements of the
width of the red blood cell distribution curve.
• The RDW-CV is calculated from the width of the
histogram at 1 SD from the mean divided by the MCV.
• The normal RDW-CV is 13 ± 1%.
• It reflects degree of variation in size and shape of red
blood cells as calculated by automated analyzers
• RDW is measured as a coefficient of variation of red
cell size distribution.

13. Complete blood count
Platelet count
• Are also called thrombocytes
• Plays a role in normal blood clotting
• CBC measures the number and size of
platelets present
• Excess platelets cause excessive clotting
• Low or non-functioning platelets cause
excessive bleeding.

14. Peripheral blood film (PBF)
• Parasites
– Malaria, microfilaria, trypanosomes
• Reticulocytes
– Seen in increased synthesis e.g.,
Bleeding, haemolysis, marrow disease, response
to haematinics
• Bone marrow film may show much more
– Parasites, leukaemias, destructive diseases

15. BLEEDING
• Prothrombin time (PT)
– Sensitive to warfarin
– Standardised as INR (International Normalised Ratio)
– Reflects liver function too
• Activated Partial Thromboplastin Time
– APTT
– Sensitive to unfractionated heparin but not Low
Molecular Weight Heparin