A REVIEW OF HEMATOLOGY.pdf

1
SHALOM UNIVERSITY INC
A REVIEW OF HEMATOLOGY
Presented by
Name: KELLY HYCIENTH KUM
Tel: 670929402
Email: Hycienthkelly9@gmail.com
Field of Studies: Medical Laboratory Sciences
School : Shalom University Inc

2
Contents
1 BLOOD: Hematocrit (HCT)..............................................................................................................4
1.1 Measurement of hematocrit.......................................................................................................4
1.2 Components of the various layers, clinical indications and importance................................4
1.2.1 The densest layer or erythrocytes (the PCV layer)..........................................................4
1.2.2 The buffy coat......................................................................................................................5
1.2.3 Plasma..................................................................................................................................5
2 ERYTHROPOIESIS AND THE LIFE SPAN OF RED BLOOD CELLS ....................................7
2.1 ERYTHROPOISIS. ....................................................................................................................7
2.1.1 COMPONENTS OR REQUIREMENTS FOR EFFECTIVE ERYTHROPIOESOS..7
2.1.2 SOURCES, TRANSPORT AND ABSORPTION OF THE VARIOUS
REQUIREMENTS OR COMPONENTS .........................................................................................7
2.1.3 LIFE SPAN AND DESTRUCTION OF RED BLOOD CELLS (ERYTHROCYTES)9
3 ANEMIA............................................................................................................................................12
3.1 TYPES OF ANEMIA ...............................................................................................................12
3.1.1 IRON DEFICIENCY ANEMIA ......................................................................................12
3.1.2 VITAMIN B12/ FOLIC ACID DEFICIENCY ANEMIA (Pernicious Anemia) .........13
3.1.3 HEREDITARY SPHEROCYTOSIS..............................................................................13
3.1.4 GLUCOSE-6- PHOSPHATE DEHYDROGENASE DEFICIENCY (G6PD)
ANEMIA............................................................................................................................................13
3.1.5 SICKLE CELL ANEMIA................................................................................................14
3.1.6 HEMORRHAGIC ANEMIA...........................................................................................14
3.1.7 APLASTIC ANEMIA.......................................................................................................14
3.1.8 THALASSEMIA...............................................................................................................14
4 POLYCYTHEMIA...........................................................................................................................16
4.1 PRIMARY POLYCYTHEMIA (POLYCYTHEMIA VERA) .............................................16
4.2 SECONDARY POLYCYTHEMIA.........................................................................................16
5 LEUKOPOIESIS ..............................................................................................................................17
5.1 DIFFERENTIAL WHITE BLOOD CELLS, NORMAL RANGE AND FUNCTION.......18
6 HEMOSTASIS..................................................................................................................................20
6.1 PREVENTION OF CLOT FORMATION IN THE VASCULAR SYSTEM .....................20
6.2 MECHANISMS OF HEMOSTASIS.......................................................................................20
6.2.1 VASCULAR SPASM........................................................................................................20

3
6.2.2 PLATELETS PLUG FORMATION...............................................................................21
6.2.3 THE COAGULATION CASCADE ................................................................................21
6.2.4 CLOT RETRACTION AND REPAIR ...........................................................................22
6.2.5 FIBRINOLYSIS................................................................................................................22
6.2.6 TREATMENT OF COAGULATION PROBLEMS .....................................................22
7 BLOOD TYPING..............................................................................................................................24
7.1 Hemolytic Disease of the new born (erythroblastosis fetalis)................................................27
8 APPROACH TO ANEMIA..............................................................................................................28
8.1 ANEMIA DUE TO DECREASED PRODUCTION OF ERYTHROCYTES (RI <2%)....29
8.1.1 Microcytic Anemia (MCV < 80FL) .................................................................................29
8.1.2 NORMOCYTIC ANEMIA ..............................................................................................30
8.1.3 Macrocytic anemia (MCV>100fL) ..................................................................................32
8.2 Increase destruction of RBC....................................................................................................32
8.3 Blood loss ...................................................................................................................................35
9 Approach to polycythemia ...............................................................................................................36
HEMATOLOGY SUMMARY

4
1 BLOOD: Hematocrit (HCT)
It is the percent erythrocytes or RBCs in a given volume of blood. It is also called the packed cell
volume (PCV).
1.1 Measurement of hematocrit
Blood is collected in a tube, say a 1mm long micro capillary tube.
Centrifuged for some time in a hematocrit centrifuge.
The blood will separate into three (3) layers. See diagram below
Figure 1. Tube showing the various layers of separated blood.
1.2 Components of the various layers, clinical indications and importance.
1.2.1 The densest layer or erythrocytes (the PCV layer).
It is made up entirely erythrocytes or RBCs.
Calculation of hematocrit (PCV OR HCT)
The normal length of the PCV layer is 0.45ml.

5
Therefore, the PCV in % is 0.45/1ml *100 = 45%.
Note
 Normal value of PCV is 45%.
 A PCV value of <45% is called Anemia.
 A PCV value of >45% is called Polycythemia.
 The normal range of RBCs in 1µl is 5,000,000 – 6,000,000cells/ µl.
1.2.2 The buffy coat
This makes up <1% or <0.1ml of the blood. It is made up of the following formed elements:
i. Platelets, normal range 150,000 – 450,000cells/ µl.
 Low platelets count of <150,000cells/ µl is called thrombocytopenia.
 High platelets count of >450,000cells/ µl is called thrombocytosis.
ii. White blood cells (WBCs), normal range 4,800 - 11,000cells/ µl.
 Low white blood cell count, <4800cells/ µl is called leukopenia.
 High white blood cell count, >11,000cell/ µl is called leukocytosis.
1.2.3 Plasma
Make up about 55% (0.55ml) of the whole blood. 90 -93% of plasma is water, a universal
solvent which dissolve many solutes. About 8% of plasma is plasma protein with albumin
making up 60% and the rest of the 40% are plasma globulins (alpha, beta and gamma
globulins).
a) Functions of albumin
 Maintenance of osmotic pressure
 Transport of gases e.g. oxygen, carbodioxide, nitric oxide etc.
 Transport of electrolytes e.g. sodium, potassium, chloride etc.
 Transport of metabolic wastes e.g. creatinine, urea etc.
 Transport of enzymes.
 Transport of hormones.
 Transport of nutrients e.g. glucose, amino acids, fatty acids, etc.
b) Functions of globulins

6
 Alpha(α) and beta(β) globulins are good transport proteins e.g. transferrin, and thyroxin
binding globulin (TBG).
 Gamma(Γ) globulins are antibodies, they are produced by B-cells and they fight
infections.

7
2 ERYTHROPOIESIS AND THE LIFE SPAN OF RED BLOOD CELLS
2.1 ERYTHROPOISIS.
It is the normal production of red blood cells (erythrocytes) in the bone marrow. This process is
triggered or stimulated by;
 Blood loss due to bleeding.
 low oxygen concentration, like in high altitudes.
 Anemia, low oxygen carrying capacity of red blood cells.
All the above leads to a common condition called hypoxia.
2.1.1 COMPONENTS OR REQUIREMENTS FOR EFFECTIVE ERYTHROPIOESOS.
 Iron (Fe3+
), for the formation hence group in hemoglobin.
 Folic acid/ vitamin B12 for DNA transcription and transportation during the globin
synthesis
 Erythropoietin (EPO), a hormone which triggers and controls the process (erythropoiesis)
 iv) Nutrients like amino acids, carbohydrates, fats which are used in the synthesis of
hemoglobin and the cytoskeleton.
2.1.2 SOURCES, TRANSPORT AND ABSORPTION OF THE VARIOUS
REQUIREMENTS OR COMPONENTS
Fe(iron): It is gotten from exogenous sources, from food and also stored the liver.
- Iron is ingested in the form of Fe3+
. In the duodenum, Fe3+
is reduced to Fe2+
by the enzyme
duodenum cytochrome B (D Cyto B).
- The Fe2+
is transported into interstitial fluid by Divalent metal transporter I (DMI-I) in the
presence of H+
.
-The Fe2+
binds to EPO ferritin inside the interstitial cells to form ferritin.
- Some of the ferritin cluster together to form hemosiderin and some of the Fe2+
deposited in the
membranes of the cells is transported out by ferroprotein and oxidized to Fe3+
by hephaestin.
-the Fe3+
then enters the blood stream and binds to transferrin, to avoid the formation of free
radicals which are toxic.

8
- Transferrin transport the Fe3+
to the bone marrow and other organs like the liver for storage.
- At the liver, the transferrin carrying Fe3+
binds to a transport protein in the cell membranes,
where it is carried into the cell
- In the cell, it binds to a protein and produces hepcidin which controls the activities of
ferroprotein.
-Also, in the cell membrane, there is another protein called HFG which regulates the function of
hepcidin.
NB: Absence of HFGs, leads to malfunctioning of hepcidin hence the activity of ferroprotein is
not well controlled. This causes a disease called hemochromatosis.
VITAMIN B12. It is also gotten from diet (food) in the stomach, there are parietal cells that
produces intrinsic factor (I.F). The intrinsic factor binds to vitamin. It carries vit B12 through
the duodenum, juedenum and ileum of the small intestine which it binds to a receptor side bound
to a transport protein.
-The complex moves through the cell membrane where B12 is released into the circulation. In
the circulatory system, it binds to another protein called Transcobalamin I am II.
Folic acid: It goes through the same pathway like iron.
Nutrients: (carbohydrates, fats and Amino acids).
See digestion for details
Erythropoietin: It is produced at the Bowman’s capsule of the kidney nephron, where a
transcription protein called hypoxic inducible factor (HIF) binds to EPO (Erythropoietin) gene,
synthesize erythropoietin, which is released into circulation and carried to the target side in the
bone marrow.
The changes that take place in the cytoplasmic organelles of erythrocytes precursors to
the mature erythrocyte is best illustrated on the diagram below.

9
Figure 2: process of erythropoiesis
2.1.3 LIFE SPAN AND DESTRUCTION OF RED BLOOD CELLS (ERYTHROCYTES)
Life span of RBC. The life span of RBCs is 100 - 120days.
Cytoskeletal structure of RBCs. It contains a helical or web cell membrane protein called
Spectrin held to the cells membrane by transmembrane protein called Ankyrin. The cells
membrane also has Glycophorins, Bend 4.1 or 4.2 protein. All these proteins give the RBCs
pliability or flexibility to squeeze through the sinusoidal capillaries of the endothelial reticulum
system of the spleen.
Destruction of RBCs at the spleen
The Destruction of RBCs is brought about by the degradation of cell membrane protein,
Spectrin, transmembrane protein Ankyrin and the Glycophorins, bend 4.1 or 4.2 which causes
the cell to become stiff or rigid and no more flexible or pliable to pass through the sinusoidal
capillaries of the endothelium reticulum of the spleen where they are engulfed by macrophages.
The macrophages releases enzymes that breaks down the hemoglobin into the heme group and
globulin group.
- The globulins are further broken down to Amino Acids which are recycled
- The heme releases Fe2+
which binds to EPO ferritin to form ferritin that clust together to form
hemosiderin for storage.
- The porphyrin of the heme is broken down to Biliverdin, and Biliverdin is further broken down
to Bilirubin which goes into the blood stream.
Influx of Fe2+, b12/b9

10
-In the blood stream, Bilirubin binds to Albumin to form unconjugated Bilirubin. Albumin
transport it to the liver.
-In the liver, Bilirubin goes into the gall bladder where it mixes with bile and glucuronic acid
forming conjugated bilirubin (direct bilirubin). Then it pushed out through the bile duct into the
duodenum. In the duodenum, the Bilirubin is further broken down to Urobilinogen due to the
presence of enzyme producing bacteria which produces protease.
- 10% of the urobilinogen is absorbed back into the blood stream, some goes to the kidney for
excretion, some is further broken down to Stercobilin which is excreted in Stool and gives
coloration to the stool(feces).
Note: Blockage of biliary duct causes production of uncolored Stool or feces, and this can push
back Bilirubin Into the blood stream like in the case of gallstones which leads to Jaundice.

11
Figure 3: Destruction of red blood cells.

12
Figure 4: Blood picture of severe IDA
3 ANEMIA
Anemia is low oxygen carrying capacity of red blood cells which can be due to low number
of red blood cells or dysfunction of red blood cells.
3.1 TYPES OF ANEMIA
1) Iron deficiency Anemia
2) vitamin B12/ Folic Acid deficiency Anemia (pernicious Anemia)
3) Hereditary spherocytosis
4) G6PD (Glucose- 6- phosphate dehydrogenase deficiency)
5) Sickle cell Anemia
6) Hemorrhagic Anemia
7) Atlantic Anemia
8) Thalassemia
3.1.1 IRON DEFICIENCY ANEMIA
Iron is needed in the synthesis of the heme group in the hemoglobin molecule
3.1.1.1 CAUSES OF IRON DEFICIENCY ANEMIA
- Loss of blood
- Heavy menstruation
- low iron in diet (this is common with vegetarians).
3.1.1.2 CLINICAL MANIFESTATIONS OF IRON DEFICIENCY ANEMIA
- Dyspnea (shortness of breath)
- Fatigue (feeling tired)
- Tachycardia (increased workload of the heart)
- Dizziness (feeling weak)
Note: In iron deficiency Anemia, the mean cell volume < 90fL (microcytosis)

13
Figure 5: Blood picture of vit b12 deficiency
3.1.2 VITAMIN B12/ FOLIC ACID DEFICIENCY ANEMIA (Pernicious Anemia)
Vitamin B12/ Folic Acid is needed in for DNA maturation during the synthesis and
condensation of hemoglobin.
3.1.2.1 Causes of pernicious anemia
- It is due to the production of antibodies against the intrinsic factor, a vitamin B12 transport
protein produced by the parietal cells of the stomach. The absence of vitamin B12/ Folic Acid in
the erythropoietic tissue, leads to the malformation of RBCs. The cells are large or macrocytic
due to the fact that hemoglobin is not well synthesized and condensed
MCV > 90fL (macrocytosis)
3.1.2.2 TREATMENT Of Pernicious Anemia
IM injection of vitamin B12
3.1.3 HEREDITARY SPHEROCYTOSIS
This is due to genetic mutation that lead the malformation of transmembrane, Ankyrin and
the helical protein, Spectrin. It can go a long way to affect the Glycophorins, bends protein 4.1
or 4.2. Instead of helical shape, they form a spherical shape hence the name Hereditary
spherocytosis. These cells can get stocked in the spleen causing splenomegaly and they are
phagocytized by macrophages.
3.1.4 GLUCOSE-6- PHOSPHATE DEHYDROGENASE DEFICIENCY (G6PD)
ANEMIA.
This is also due to a genetic mutation that the enzymes G6PD is not produced or produced in
low quantities. G6PD is used in the Glycolytic pathway for the enzymatic conversion of Glucose
-6- phosphate to 6-phospho - gluconate. For this process NADPH is produced which maintain
the level of Glutathione (GSH), that helps in the removal of free radicals like Hocl-
, O2+
, OH-
,
H2O2 by forming H2O.
Accumulation of free radicals causes precipitation of hemoglobin molecule forming Heinz
bodies on the cell membrane of RBCs. This causes to pitting and destruction of red blood cells of
the level of the spleen.
Figure 6: showing heinz bodies

14
Figure 6: blood picture showing sickled cells
3.1.5 SICKLE CELL ANEMIA
This can be termed midstream mutation because the 6th Amino Acid (Glutamic Acid) is replaced
by Valine in the beta - chain during the synthesis hemoglobin molecule. Hemoglobin is made up
of 2 alpha and 2beta chains. This replacement, lead to the polymerization of hemoglobin and
sickling of red blood cells in hypoxic condition causing vaso - occlusion crisis.
TREATMENT
- Give oxygen
- Pain relieve (analgesics)
- Administer intravenous fluids
- Hydroxyl urea
3.1.6 HEMORRHAGIC ANEMIA
It is a type of Anemia that results from direct blood loss through accidents or heavy
menstruation. It can also be caused by gastrointestinal bleeding that is caused by helicopter
pylori Infection.
3.1.7 APLASTIC ANEMIA
About 60% of people suffering from aplastic Anemia is idiopathic. It can be caused by
viruses, bacteria, drugs like chloramphenicol, radiations that affects the myeloid stem cells in the
bone marrow. It is also termed pancytopenia because it causes decreased of RBCs, platelets and
WBCs.
TREATMENT
- Bone marrow transplant
3.1.8 THALASSEMIA
It is more common with the Mediterranean ancestry. It is a genetic mutation where there is
deficiency in the synthesis of one strand of the globin chain.
There are two types; Alpha and beta Thalassemia.

15
1. Alpha Thalassemia; lack of 1 alpha chain hence the individual has one alpha and two
beta.
2. Beta Thalassemia; lack of 1 beta chain hence the individual has two alpha and one beta.
NB: In both individuals, the MCV < 90 (microcytic Anemia)
Treatment
Bone marrow transplant.

16
4 POLYCYTHEMIA
Polycythemia is a condition where there is increased production of RBCs in the bone
marrow. It can be caused by the hyperfunctioning of the JAK STAT (signal transducer
Activated Transmission) pathway in the bone marrow and by secondary factors that triggered the
increase production of EPO.
There are two types of polycythemia:
1. Primary polycythemia (polycythemia Vera).
2. Secondary polycythemia.
4.1 PRIMARY POLYCYTHEMIA (POLYCYTHEMIA VERA)
Primary polycythemia occurs in the bone marrow and is caused by the hyperfunctioning of JAK
STAT (signal Transducer Activated Transmission) pathway which activates the process of
transcription and translation in the nucleus of the myeloid stem cells hence increasing the rate of
proliferation of Red blood cells.
SYMPTOMS
- Increase in blood viscosity which lead to increase blood pressure
- Increase Incidence of thrombosis and myocardial infarction
-Increase bleeding and a longer prothrombin Time
Note: Blood doping can cause a transient form of polycythemia
4.2 SECONDARY POLYCYTHEMIA
It's a type of polycythemia caused by an increased production of Erythropoietin on the cells of
the tubules triggered by:
- Cancers at level of the tubules
- Cardiovascular diseases
- High altitudes
Increased Erythropoietin production, increased erythropoiesis.

17
5 LEUKOPOIESIS
This is the process of formation of white Blood cells from the pluripotent hematopoietic
stem cells in the red bone marrow. This process is triggered and controlled by specific colony
stimulating factors and inter- leukins 3 and 5. This process involves the two cells lineage (the
myeloid and lymphoid) lineage and they give rise to individual white Blood cells.
i) The myeloid stem cells. The myeloid stem cells divide, differentiate and mature into various
white Blood cells, neutrophils, and Eosinophils, Basophiles and monocytes
Note that thrombocytopenia’s will also be covered in this chapter because platelets is one of the
daughter cells of the myeloid stem cells.
ii) The lymphoid stem cells. It divides, differentiate into beta - lymphocytes and T-
lymphocytes.
Note. The differentiation and maturation of these different cells are based on their structural
changes at the level of the nucleus size and shapes, the formation of granules and coloration of
granules when stained with Romanowsky stain. This process can best be illustrated below in the
schematic.
Figure 7: diagram illustrating leukopoiesis.

18
Figure 8: monocyte
Figure 9 basophil
Figure 10: Eosinophil
5.1 DIFFERENTIAL WHITE BLOOD CELLS, NORMAL RANGE AND FUNCTION
1) Monocytes:
-They move to the tissues and become macrophages
-Normal range 3 to 8%.
-they carryout phagocytosis - Antigen producing cells.
They are found in the following organs or tissues
- Microglia in the central nervous system
- Kuffers cells in the liver
- Alveoli macrophages in the lungs
- Osteo clast in the bone.
2) Basophils
- Highly granulated that obscure the cytoplasm
- Normal range 3 - 8%
- Granules produces Heparin, an anticoagulant.
- Granules produces Histamines, which regulate inflammation
3) Eosinophils
- Has orange Granules
- Bilobed nuclei
- Normal range is 2 - 4%
- Produces cationic and major proteins that kills parasites
- Play a role in type I hypersensitivity

19
Figure 11: Neutrophils
Figure 13:
Lymphocyte
Figure 12: Platelets
4) Neutrophils
-Contain pink granules
- Have about 2 -4 lobes of nuclei
- Normal range 50- 70%
- They are great phagocytes
- They convert O2 - O2 - H2O2 which are toxic radicals and play a role in providing an
oxidative
BUST and NETS DNA
5) Platelets (Thrombocytes)
- They are cellular fragments produced from megakaryocytes
- Normal range 150,000 - 450,000cells/µL
- They plug blood vessels preventing bleeding where a vessel is injured
6) Lymphocytes
-They are agranulated WBCs
- Normal range 20 - 30%.
- Lymphocytes produces plasma cells that secrets antibodies to fight infections
- T- Lymphocytes, help beta lymphocytes to produce antibodies and produces cytotoxic T-cells
that induces apoptosis.

20
6 HEMOSTASIS
This is the process of stoppage of blood loss when there is a tissue damage
6.1 PREVENTION OF CLOT FORMATION IN THE VASCULAR SYSTEM
The endothelial lining of the vascular system is made up of smooth and connective tissues that
secrets a good number of chemicals that inactivated clotting factors that circulates in the blood,
hence plug formation. These chemicals are;
1) Nitric Oxide and prostacyclin I2 are secreted by the endothelial cells that inactivate platelets
aggregation or prevent them from binding on the endothelium.
2) Heparin sulfate produced by plasma cells (Basophils) binds to antithrombin, degrades factor
II, factor IX and X inhibiting clot formation.
3) Thrombomodulin found on the surface of endothelial cells binds to thrombin, reducing clot
formation or blood coagulation by degrading protein C.
Hemostasis is achieved through a sequence of mechanisms which are:
- Vascular spasms
- Platelets plug formation
- Coagulation
- Clot retraction and repair
- Fibrinolysis
6.2 MECHANISMS OF HEMOSTASIS
6.2.1 VASCULAR SPASM
There are 3 processes that occurs for Vascular spasm to take place and reduce blood loss.
-when the endothelium is damaged or broken, it secrets endothelin which binds to a receptor in
the smooth muscles causing vaso construction hence reducing blood loss.
- If the injury is directly on the smooth muscle, the smooth muscle contract. This is also called
myogenic mechanism.

21
-The tissue injury or damage can cause the release of inflammatory chemicals like histamine that
causes pain, impulse transmission in the CNS also trigger Vaso constriction.
6.2.2 PLATELETS PLUG FORMATION
Due to tissue damage, all the above-mentioned natural anticoagulants actions are inhibited.
There is influx of platelets to the injured site which binds to the receptor protein (von Willebrand
factor) on the endothelial cells. This binding causes the release of chemicals, ADP, thromboxin
A2 and serotonin from platelets granules. ADP and Thromboxin A2 Activates platelets
aggregation where the platelets are linked together by glycoprotein IIb / IIIa. Thromboxin A2
and serotonin binds onto this smooth muscle causing vaso constriction and formation of a plug at
the site of injury.
6.2.3 THE COAGULATION CASCADE
This mechanism follows immediately after the platelets plug formation and involves a series of
events to achieve the formation of a fibrin mesh which is insoluble and holds the plug firm on the
endothelium. The events go as follows;
- The negative charges (phospholipids) on the surface of the plug reacts with factor XII produced
from the liver, to activate it. Activated factor XII (XIIa) activates factor XI, then activated factor
XI (XIa) activates factor VIII in the presence of platelets factor 3 (PF3) and Ca2+ and forms a
complex. This complex of factor IX, VIII activates factor X in the presence of Ca2+ and P. F3.
Activated factor X (Xa) reacts with factor V in the presence of P.F3 and Ca2+ converting
prothrombin ( II ) to thrombin ( IIa ).
Thrombin (II) polymerizes soluble fibrinogen to insoluble fibrin. The formed fibrin is stabilized
by factor XIII (fibrin stabilizing) factor.
The coagulation cascade can further be divided into 3pathways; the intrinsic, the extrinsic, and
the common pathways as shown in figure 14 below.

22
6.2.4 CLOT RETRACTION AND REPAIR
This mechanism involves the following;
- Platelets contraction, where the platelets puff the edges of the ruptured tissues together
- The plug secrets a protein called platelets derived growth factor (P D G F) which triggers
mitosis, causing the smooth connective tissues lining to proliferate and produce collagen fibers
for repair.
- The plug secrets another protein called Vascular Endothelium Growth Factor (V E G F) to
regenerate and repair the endothelial lining.
6.2.5 FIBRINOLYSIS
This is the last mechanism and it involves;
- The Tissue Plasminogen Activator (T P A) a protein found in the endothelial lining reacting
with circulating plasminogen activation to plasmid. This plasmid begins to degrades the fibrin
clot or strand releasing fibrinogen and the polymerization D-Dimer.
6.2.6 TREATMENT OF COAGULATION PROBLEMS
Treatment depends and vary accordingly to target mechanism or factors
- Heparin molecules are used to maintain blood flow freely in the vascular system with platelets
aggregation on the endothelium
- Give ADP inhibitors like clopedegers to prevent plug formation
- Give Thromboxin A2 inhibitors to prevent plug formation
- Give Abciximab to inhibit glycoprotein IIa/ IIIb to prevent platelets aggregation
-Warfarin is a vitamin K inhibitor hence can prevent the production of factors II, III, IV by liver

23
Figure 14: Illustration of hemostasis mechanism

24
7 BLOOD TYPING
Natural antigens present on the surfaces red blood cells are responsible for blood typing. These
antigens are named A, B and the Rh and are responsible for individual’s blood type. Individuals
that do not have the A or B antigen are termed O (no or zero antigen). Individuals that do not
have the RH antigen are called RH negative (RHneg (-)
). This blood type is determined by
agglutination (clumping of red blood cells). The diagram below demonstrates agglutination test
and blood type;
Figure 15: demonstration of blood typing

25
1. Blood group A
- Has antigen-A on red blood cell surface
- has antibodies B in its plasma
a) A Rhesus positive (A+
)
Can donate to;
A+
, AB+
Can receive from;
A+
, O-
, A-
, O+
b) A Rhesus negative (A-
)
Can donate to;
A-
, AB-
, AB+
Can receive from;
A-
, O-
2. Blood group B
-has antigen-B on the surface of its red cells
-Has antibody-A in plasma
a) B Rhesus positive (B+
)
Can donate to;
-B+
, AB+
Can receive from;
B+
, O+
, B-
, O-
b) B Rhesus negative (B-)
Can donate to;
B-, AB+, AB-
Can receive from;
B-
, O-

26
3. Blood group AB
- Has antigens A and B on its red cell surface
- Has no antibody against antigens A, B in plasma
The presence or absence of Rh antigen makes an individual AB Rh- or AB Rh+
a) AB Rhesus negative (AB-
)
-Can donate to;
AB-
, AB+
-Can receive from;
A-
, B-
, AB-
, O-
b) AB Rhesus positive (AB+
)
-Can donate to;
AB+
-Can receive from;
A+
, A-
, B+
, B-
, AB+
, AB-
, O+
, O-
4. Blood group O
- Has no antigen on the surface of their red cells
- Has antibodies A and B in plasma
a) O Rhesus negative (O-
)
-Can donate to;
A+
, A-
, B+
, B-, AB+
, AB-
, O+
, O-
-Can receive from;
O-
b) O Rhesus positive (O+
)
-Can donate to;
A+
, B+
, AB+
, O+
-Can receive from;
O+
, O-

27
7.1 Hemolytic Disease of the new born (erythroblastosis fetalis)
This is hemolysis which is as a result of a pregnant woman who is Rhesus negative
producing antibodies against her Rhesus positive fetus.
During the first delivery, maternal blood mixes with fetal blood and the Rhesus
positive (Rh+) blood of the fetus leaks into the mother’s circulation and the rhesus
antigen is noticed as a foreign body.
The mother’s immune system produces anti-rhesus antibodies, IgG (from memory
cells) for any subsequent rhesus positive pregnancy.
The antibody IgG cross the placenta and attacks the baby’s red blood cells leading
hemolytic anemia.
Figure 16:illustration of erythroblastosis fetalis

28
Treatment
-Anti-rhesus antibody called RHOGAM can be administered within 48 hours after
delivery of the first child. RHOGAM binds to the anti-rhesus antibody, IgG
produced in the mother’s system and prevent damage to the fetal red blood cells.
8 APPROACH TO ANEMIA
These are the systematic steps involved in the differential diagnosis of Anemia. It involves the
use of biochemical tests, serological tests, hematological tests and microscopic examination of
PBS for the determination of the cause of the Anemia
Brief Review of Erythropoiesis / Anemia / Lifespan of RBCs
Erythropoiesis is the normal production of red blood cells. This process is driven by
hormones like EPO, T3, T4, and requires nutrients like Fe3+, vit B12, vitB9 (Folic acid), Amino
Acids, fatty acid and carbohydrates. This process takes place in the spongy tissues of the bone
marrow.
A deficiency in these hormones, nutrients and an increased exposure of the bone marrow to
toxic drugs, radiations and other chemical can decrease the production of red blood cells and also
increase the rate of destruction of the red blood cells. Blood can also be loss through GIT
bleeding or in case of accidents. All these lead to a condition called Anemia, where there is
decreased Hct, Hb, and RBCSs, reticulocytes index vary depending on the level of the effects.
Considering the RI (reticulocytes index) as the first line test, the cause of Anemia can be
group into;
1. Anemia caused by decreased production of red blood cells, indicated by a RI value of >
2%.
2. Anemia caused by increased red blood cells destruction, with RI value of <2%.

29
3. Anemia caused by direct blood loss, RI value >2%.
8.1 ANEMIA DUE TO DECREASED PRODUCTION OF ERYTHROCYTES (RI
<2%)
In Anemia, there is decreased HCT, Hgb, and RBCs, but Hct and Hgb are of great
importance in the differential diagnosis. These parameters are expressed in the mean cell
volume (MCV) Hence Anemia due to decreased production (RI<2%) can be subdivided into:
 microcytic Anemia, MCV <80fl
 Normocytic Anemia, MCV, 80 - 90fl
 macrocytic Anemia, MCV >90fl
8.1.1 Microcytic Anemia (MCV < 80FL)
There are a good number of deficiencies tor Anemias that presents with microcytes.
They are:
i. Iron deficiency Anemia (IDA).
ii. Anemia of chronic disease (ACD)
iii. Thalassemia
iv. Sideroblastic Anemia
There are a good number of laboratory tests used or ordered to differentiate these various
microcytic Anemia. They include:
 Red blood cell distribution with (RDW).
 Red blood cells count
 Mean cell index (MCI= MCV/ RBC)
 Iron studies which involves Fe3+ levels, TIBC, ferritin and transferrin saturation. Note,
only ferritin levels, transferrin will be of great help.
 ferritin
 transferrin saturation (Fe3+/ TIBC)
 Microscopic examination of the peripheral blood smear (PBS)
 Patients history

30
8.1.1.1 Iron Deficiency Anemia (IDA)
 RDW is high
 RBC is low
 Mean Cell Index (MCI) > 13%
 Ferritin level is low
 Transferrin saturation is low
8.1.1.2 Anemia of Chronic Disease (ACD)
 RDW is Normal
 RBC is low
 ferritin is high
 History is very helpful
8.1.1.3 Thalassemia
 RDW can be high or normal
 RBC is normal
 MCV <70fl hence MCV <13%
 History is important (common amongst the Mediterranean)
 PBs - shows Basophilic stippling
 Hb electrophoresis
8.1.1.4 Sideroblastic Anemia. Inability to use iron stores.
 RDW is high
 RBS is low
 PBS reveals basophilic stippling
 History is toxic drugs used or lead poisoning is very helpful
 Sideroblasts are confirmed on bone marrow aspirates.
8.1.2 NORMOCYTIC ANEMIA
There are a good number of hormones deficiencies, vitamin deficiencies and disease conditions
that cause normocytic anemia. Evaluation of the levels of these hormones, vitamins and
functionality of organs concern with erythropoiesis can be diagnostic of this type of anemia.
These tests include:

31
1. Measurement of the levels of ferritin, vitamin b12 and folic acid (vitamin B9).
2. Do thyroid function tests (TFTs), kidney function tests (BMP), and liver function tests (LFTs).
3.Do Bone marrow analysis.
8.1.2.1 Measurement of ferritin levels
The essence is to differentiate between IDA and ACD that present with normal MCV.
NB: Ferritin level is high in ACD and low in IDA.
8.1.2.2 Measurement of vitamin B12 and B9 levels
If any of these vitamins is low, it is diagnostic.
If they are in the borderline, check levels of methylmalonic acid and homocysteine.
In B12 deficiency, methylmalonic acid level is high and homocysteine level is high while in B9
deficiency, methylmalonic acid level is normal and homocysteine is high.
8.1.2.3 Checking thyroid function tests (TFTs), T3and T4.
A decrease in the levels of TFTs, indicate hypothyroidism. T3 and T4 drives the process of
erythropoiesis.
8.1.2.4 Measurement of LFTs (Alb, AST, ALT, GGT, ALP).
An increase in the LFTs, indicate Liver disease.
Acanthocytes in peripheral blood smear also reveals chronic liver disease with biliary
obstruction.
8.1.2.5 Check BMP (kidney function tests).
Evaluate particular the value of creatinine, it is high in kidney disease hence a decrease in
erythropoietin production.
Bone marrow biopsy analysis.
This is very important if the reticulocyte index is very low (<0.1%). Check for pancytopenia
which can be arising from
-low proliferation of cells, in case of aplastic anemia
- myeloid dysplastic syndrome (MDS).

32
8.1.3 Macrocytic anemia (MCV>100fL)
The following tests and analyses can be used to diagnose the cause of macrocytic anemia.
Evaluation of the levels of B12 and B9 is diagnostic.
check LFTs, TFTs, alcohol level and medication.
Do bone marrow biopsy analysis.
Check for hypersegmented neutrophils in peripheral blood smear.
8.2 Increase destruction of RBC
Increase destruction of RBC (hemolysis) May occur in the bloodstream (intravascular hemolysis)
or in the macrophages (extravascular hemolysis). This increased hemolysis may be due to
infections (e.g. plasmodium infection), or structural membrane proteins malformation in the
RBC (e.g. spherocytes), or hemoglobin malformation (e.g. sickled cells) or autoimmune
hemolysis.
When there is hemolysis, molecules (LDH, bilirubin, hemoglobin) will be released into the
bloodstream. Transport proteins (haptoglobin and albumin) in the bloodstream transport these
molecules to various organs for and elimination. So, measurement of the levels these molecules
can help diagnose the cause of anemia.
The first line tests used to confirm hemolysis are;
1. Lactate Dehydrogenase (LDH), its levels in blood increases during hemolysis and
extremely high during intravascular hemolysis.
2. Haptoglobin level: it decreases during hemolysis due to its activity in transporting
bilirubin to the liver for conjugation.
After confirming hemolysis, there is a need to know whether the hemolysis is caused by
autoimmune antibodies or it is caused by intrinsic problems with the RBCs (membrane problem,
enzymes deficiencies in the cell, hemoglobin molecule abnormality) or extrinsic hemolysis
caused by abnormalities in the cardiovascular system. This take us to the next step:

33
NB: Peripheral blood smear observation is also very helpful before taking the next step because
reveals abnormal cells like sickled cells, spherocytes etc.
3. Direct antigen test (DAT). Also called comb's test used to diagnose autoimmune
hemolytic anemia and to distinguish the two (2) types of autoimmune hemolytic anemia.
i. For cold autoimmune hemolytic anemia, IgG antibodies is negative while complement is
positive.
ii. For warm autoimmune hemolytic anemia, IgG antibodies is positive and complement is
positive.
If DAT is negative, then check intrinsic factors;
4. G6PD deficiency
- Measure the level of G6PD.when it is low, then it diagnostic.
-Check for Heinz bodies and bit cells in the peripheral blood smear.
- Patient history is also very helpful.
5. Sickle cell anemia
-Check for sickled cells in the peripheral blood smear.
-Do Hgb electrophoresis to confirm.
-Patient family history is also helpful.
6. Membrane problem
i. hereditary spherocytosis
-Check for spherocytes in the PBS
-Patient history is also very important.
-Confirmed by a positive osmotic fragility test.
ii. Paroxysmal Nocturnal Hemoglobinuria (PNH).
-Check history of clots formation and passing of dark urine in AM.

34
-Check for spherocytes in the PBS
-Confirm with a positive flow cytometry test.
After doing all the above analysis and we have not yet gotten the exert cause of the hemolysis,
this takes us to the extrinsic factors;
1. MAHA (microangiopathic Hemolytic Anemia). The common indication of MAHAs is
thrombocytopenia. They are many types of MAHAs. This includes;
i. DIC (disseminated intravascular coagulation). In this type of MAHA, there is increase
PT, PTT, INR, and D-dimer.
ii. TTP (Thrombocytopenic Purpura). Presenting with decreased platelets count, RBC,
fever and neuro deficit.
iii. HUS (Hemolytic uremic Syndrome). Common among children, they present with GIT
problem due to Chagas toxins.
iv. HELLP (Hemolysis Elevated Liver Enzymes and Low Platelets). Common with
pregnant women. Low platelets count and high LFTs.
NB. It is worth noting that in all the MAHAs peripheral blood smear reveals Schistocytes and
helmet cells may be present.
2. Infections. The person must be presenting with very high fever and rash.
i. Malaria
History of recent travels to endemic area like the tropics is helpful.
Peripheral blood smear reveals inclusions of the parasites in RBCs.
ii. Babesiosis
The patient present with rash and tick bites
PBS is maltele cross positive
iii. Disseminated Cdiff.
The patient present with diarrhea and vomiting

35
PBS show ghost cells
8.3 Blood loss
Confirm no evidence of Hemolysis (LDH and haptoglobin values are normal)
1. Do physical examination
-Is the client looking pale?
-Is he having pallors, tachycardia?
- Any frequent blood draw or surgery?
2. check also for GIT bleeding
For upper GIT bleeding
- do EGD
-do nasogastric tube aspiration
For lower GIT bleeding
-do C-scope
-FOB test
3. check also Reta pelvic bleeding
-do CTA of the abdominopelvic region.

36
Figure 17: schistocytes, common with MAHAs
Figure 18: Picture of Ghost Cells
9 Approach to polycythemia
Polycythemia is an increase production of red blood cells. Polycythemia is reflected on the
elevated values of Hct, Hgb, and RBC in a complete blood count.
Approach to polycythemia are the systematic laboratory tests done to diagnose the cause of
polycythemia. These tests are as follows:
1. Check the red blood cell mass.
If the red blood cell mass is normal, then this probably Relative Erythrocytosis or
hemoconcentration where the plasma volume drops due to:
 dehydration
 diarrhea
 vomiting

37
 diuretics
If the red blood cell mass is high, this is suggestive of primary or secondary polycythemia. This
takes us to the next step
2. Check the EPO levels:
If the EPO level is low, then it is certainly Primary Polycythemia where an increase in
proliferation of functional red blood cells send a negative feedback to the kidney nephron to stop
secretion of EPO. It can also be confirmed by a positive Jak-2 mutation test.
If the EPO level is high, this takes us to the step, finding out the source of this high EPO or
factors stimulating it production.
3. Check the oxygen saturation: it will be low in the following conditions;
 chronic smoking
 chronic lungs disease
 intracardiac shunting of blood
 Congestive heart failure
 high altitude.
All these causes hypoxia and stimulate EPO secretion.
If all the above analyses are normal i.e. oxygen saturation and patient history is normal, then we
check the source of the EPO secretion.
4. do CT scans checking for tumors especially;
 Renal cell carcinoma
 Hepatocyte carcinoma.

A REVIEW OF HEMATOLOGY.pdf

Recommended

Recommended

More Related Content

Similar to A REVIEW OF HEMATOLOGY.pdf

Similar to A REVIEW OF HEMATOLOGY.pdf (20)

Recently uploaded

Recently uploaded (20)

A REVIEW OF HEMATOLOGY.pdf