Hematology.pdf wollega university campus

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1. Yadeta Babu(B.Pharm& MSc)
Email: [email protected]
June 2024
Wallaga University
Integrated Therapeutics I
Lecture 3: Hematology

2. Contents
Complete Blood Count (CBC)
RBC
HCT
Hgb
WBC
Thrombocyte
Coagulation Studies
Aptt
PT
INR
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3. Complete Blood Count (1)
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The complete blood count (CBC) is one of the most
commonly ordered clinical laboratory tests.
A CBC measures the:-
RBCs, Hgb, Hematocrit (Hct), Mean Cell Volume
(MCV), Mean Cell Hgb Concentration (MCHC), and
total white blood cells (WBCs).
Depending on the laboratory, an order for a CBC may
also include:-
Platelets, Reticulocytes, or Leukocyte differential.

4. Red Blood Cells(Erythrocytes)(2)
Male : 4.3–5.9 ×10
6
/µL
Females: 3.5–5 ×10
6
/µL
Erythrocytes or RBCS are:-
oProduced in the bone marrow,
oReleased into the peripheral blood,
oCirculated for approximately 120 days (4 months).
oAnd cleared by the reticuloendothelial system.
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5. Red Blood Cells (Erythrocytes) (3)
The primary function of RBCSis to transport oxygen
linked to Hgb from the lungs to tissues.
The concentration of RBCSin the blood can be
measured to :-
Detect anemia, calculate RBC indices, or calculate
the hematocretin (Hct).
Hctand Hgbconcentrations are generally used to
monitor quantitative changes in RBCS.
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6. Hematocrit (Hct) (1)
Male: 40.7%–50.3%
Female :36%–44.6%
Hct(Packed cell volume) is the percentage of RBCs to
the total blood volume.
A decrease in Hct may result from bleeding, the
bone marrow suppressant effects of drugs, or
chronic diseases.
An increase in Hct may result from:-
Hemo-concentration, polycythemia vera, or
polycythemia secondary to chronic hypoxia.
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Hct= 3*Hgb
Hgb= Hct/3

7. Hemoglobin (Hgb) (1)
Male : 13.8–17.5 g/dL
Female : 12.1–15.3 g/dL
Hgb is the major oxygen-carrying compound
contained in RBCs.
Total Hgb concentration primarily depends on the
number of RBCs in the blood sample.
Medical conditions that impact the number of RBCs will
also affect Hgb concentration.
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8. Hemoglobin (Hgb) (2)
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9. Red Blood Cell Indices (1)
RBC indices (also known as wintrobe indices) are
useful in the classification of anemia.
These indices include the :-
MCV, Mean Cell Hgb (MCH), and the MCHC.
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10. MEAN CELL VOLUME (MCV) (1)
The MCV detects changes in cell size.
A decreased MCV indicates a microcytic cell,
which can result from iron-deficiency anemia or
anemia of chronic inflammation.
A large MCV indicates a macrocytic cell,
which can be caused by a vitamin B12 or folic acid
deficiency.
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11. MEAN CELL VOLUME (MCV) (2)
The MCV can be normal in a patient with:-
A “mixed” (microcytic and macrocytic) anemia.
Note that a direct assessment of a blood smear by a
microscopic examination is:-
The gold standard for confirming RBC size.
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12. MEAN CELL HEMOGLOBIN (MCHC) (1)
MCHCis a more reliable index of RBC Hgb than MCH.
MCH measures the weight of Hgb in the RBCs.
MCHC measures concentration of the RBCs
contained within a sample.
In normochromic anemias, changes in the size of RBCs
(MCV) are associated with corresponding changes in
the weight of Hgb (MCH), but the concentration of
Hgb (MCHC) remains normal.
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13. MEAN CELL HEMOGLOBIN (MCHC) (2)
Changes in the Hgb content of RBCs alter the color of
these cells.
Thus, hypochromicrefers to a decrease in RBC Hgb,
reflected by reduced MCHC, and may indicate iron-
deficiency anemia.
Conversely, hyperchromic RBCs have an elevated
MCHC because of the presence of greater amounts of
Hgb.
True IDA is Microcytic hypochromoc anemia.
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14. MEAN CELL HEMOGLOBIN (MCHC) (3)
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15. Reticulocytes (1)
Adults: 0.5%–1.5% of RBCs or 0.005–0.015
Reticulocytes are young, immature erythrocytes and
comprise about 1% of the RBCs.
The reticulocyte count measures the percentage of
these new cells in the circulating blood.
An increase in the number of reticulocytes implies
an increased number of erythrocytes are being
released into the blood in response to a stimulus.
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16. Reticulocytes (2)
Reticulocyte count is a good indicator of bone
marrow activity because it represents a recent
production.
Because erythrocytes regenerate rapidly, reticulocytosis
can be noted within 3 to 5 days after hemolysis or
after a hemorrhagic episode.
Appropriate treatment of anemias caused by iron,
vitamin B , or folic acid deficiencies should result in
an increased reticulocyte count.
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17. Erythrocyte Sedimentation Rate
ESR (1)
Reference Range: 0–30 mm/hour
The ESR is the rate (expressed in mm/hour) at which
erythrocytes settle to the bottom of a test tube through
the forces of gravity and in response to fibrinogen
levels in the blood.
The ESR is a nonspecific value and may be increased
abnormally in acute and chronic inflammatory
processes, acute and chronic infections, neoplasms,
infarction, and etc.
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18. White Blood Cells (1)
Reference Range: 3.8–9.8 ×10
3
/µL
Leukocytesor WBCs comprise five
different types of cells.
Neutrophils 40-70%
Lymphocytes, 22-44%
Monocytes, 4-11%
Eosinophils, 0-8%
Basophils. 0-3%
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19. White Blood Cells (2)
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20. White Blood Cells (3)
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21. White Blood Cells (4)
The neutrophils, eosinophils, basophils, and
monocytes are formed from stem cells in the bone
marrow.
Lymphocytesare formed primarily in the lymph
nodes, thymus, spleen, and, to a lesser extent, bone
marrow.
Each WBC type has unique function, and it is best to
consider them independently rather than collectively as
“leukocytes.”
All WBCs contribute to host defense mechanisms.
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22. Neutrophils (1)
Reference Range: 40%–70% of WBC
The terms polymorphonuclear (PMN), and
granulocytesare synonymous with neutrophil in clinical
practice.
The number of neutrophilsis commonly increased
during bacterial or fungal infections,.
When the bone marrow increases production of new
leukocytes, there is also an increase in the number of
circulating immature neutrophils (bands).
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23. Neutrophils (2)
This phenomenon is commonly referred to as a “left
shift,” which suggests acute bacterial infection.
However, neutrophiliaalso occurred in some
noninfectious diseases,
such as rheumatoid arthritis, inflammatory bowel
disease, asthma, MI, or gout.
Increased neutrophils or neutrophilia can also be
encountered during metabolic toxic states (e.g.,
diabetic ketoacidosis, uremia, and eclampsia.
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24. Agranulocytosis and Absolute
Neutrophil Count (1)
Neutropenia, is defined as a neutrophil count of <
2,000 cells/µl;
Agranulocytosis refers to severe neutropenia.
The most common causes of neutropenia are:
Metastatic carcinoma, lymphoma, and
chemotherapeutic agents.
The degree of neutropenia is often expressed by the
absolute neutrophil count (ANC).
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25. Agranulocytosis and Absolute
Neutrophil Count (2)
The ANC can be calculated as:
WBC *(% neutrophils + % bands)/100.
Generally, the risk of infection is low when the ANC
exceeds 1,000/ µL;
However, the risk of infection increases significantly
when the ANC is less than 500/µL.
The risk of developing bacteremiais increased further
as the ANC decreases to less than 100/µL, a condition
commonly referred to as “profound neutropenia”.
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26. Lymphocytes (1)
Reference Range: 22%–44% of WBC
Lymphocytes is the second most common WBC in
circulating blood.
These leukocytes respond to foreign antigens by
initiating the immune defense system.
The vast majority of lymphocytes are located in the
spleen, lymph nodes, and other organized lymphatic
tissue.
The lymphocytes circulating in blood represent less
than 5% of the total amount in the body.
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27. Lymphocytes (2)
There are two major types of lymphocytes.
T lymphocytes participate in cell-mediated
immune responses, and
B lymphocytes (bone marrow derived) are
responsible for humoral antibody responses.
Therefore, diseases affecting lymphocytes primarily
manifest themselves as immune deficiency disorders
that render the patient unable to defend against
normal pathogens.
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28. Monocytes (1)
Reference Range: 4%–11% of WBC
Monocytes are formed in the bone marrow and are
the precursors to macrophages and dendritic cells.
Macrophages and dendritic cells are phagocytic cells
that engulf foreign antigens or dead or dying cells.
Dendritic cells also present fragments of antigens to T
and B lymphocytes.
Monocytosismay be observed in , subacute bacterial
endocarditis, malaria, and tuberculosis.
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29. Eosinophils (1)
Reference range: 0% –8% of WBC
Eosinophilshave surface receptors that bind IgGand
IgE, they can modify reactions associated with IgG-
and IgE-mediated degranulation of mast cells.
Primary lysosomal granules, small dense granules,
and specific or secondary granules are the three
types of granules found within eosinophils.
The latter granules account for most of the biologic
activity of eosinophils and are toxic to parasites, tumor
cells, and some epithelial cells.
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30. Eosinophils (2)
Eosinophils have phagocytic activity, catalyze the
oxidation of many substances, facilitate killing of
microorganisms, initiate mast cell secretion.
Protect against various parasites, and play some role
in host defense.
Eosinophilia is associated with allergic reactions to
drugs, allergic disorders ( hay fever, asthma, and
eczema),
Invasive parasitic infections (e.g., hookworm,
schistosomiasis, and trichinosis), and malignancies.
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31. Basophils (1)
Reference Range: 0%–3% of WBC
During infection or inflammation, basophils leave the
blood and mobilize as mast cells to the affected site
and release granules.
These granules contain histamine, serotonin,
prostaglandins, and leukotrienes.
Degranulation results in an increased blood flow to the
site and may compound inflammatory processes.
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32. Basophils (2)
An increase in basophils commonly accompanies:-
allergic and anaphylactic responses, chronic
myeloid leukemia, myelofibrosis, and
polycythemia vera.
A decrease in the number of basophils is generally not
readily apparent because of the small number of these
cells in the blood.
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33. Thrombocytes (1)
Reference Range: 150 –450 ×10
3
/µL
Thrombocytes, commonly referred to as platelets, are
tiny fragments of cells thatassist with normal blood
clotting.
Platelet testing is included as part of a CBC and is
often ordered along with other coagulation studies to
evaluate bleeding and/or clotting disorders.
Decreased platelet counts or thrombocytopeniamay
lead to petechiae , ecchymosis, and spontaneous
hemorrhage.
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34. Thrombocytes (2)
Causes of thrombocytopenia include:-
Decreased platelet production,
Accelerated destruction,
Loss from excessive bleeding or trauma,
Dilution of blood samples secondary to blood
transfusion,
Sequestration secondary to hypersplenism,
Disseminated intravascular coagulation, infection, or
systemic lupus erythematosus.
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35. Thrombocytes (3)
Malignancy, rheumatoid arthritis, iron-deficiency
anemia, polycythemia vera, and post-splenectomy
syndromes are the most common causes of elevated
platelet counts or thrombocytosis.
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36. Coagulation Studies (1)
The control of bleeding depends on the:-
Formation of a platelet plug and the formation of a
stable fibrin clot.
The formation of this clot depends on the complex
interactions of plasma proteins and clotting factors.
The prothrombin time (PT), international normalized
ratio (INR), and activated partial thromboplastin
time (aPTT):
Are used to diagnose coagulation abnormalities or to
monitor the effectiveness of patients receiving
anticoagulation therapy.
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37. Activated Partial Thromboplastin
Time (aPTT) (1)
Reference Range: 22–37 Seconds
aPTT measures the time it takes the body to form a
clot.
aPTT depends on the activity of factors VIII, IX, XI, and
XII(intrinsic pathway) and the factors involved in the
final commonpathway of the clotting cascade (II, X,
and V).
aPTTis commonly measured to detect bleeding
disordersand coagulation deficiencies and monitor
unfractionated heparin therapy.
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38. Prothrombin Time (PT) (1)
Reference Range: 10 –13 seconds
Prothrombinis synthesized in the liverand is converted to
thrombinduring the blood clotting process.
Thrombin formation is the critical event in the hemostatic
process because thrombin creates fibrin monomers that
ultimately assemble into a clot and stimulates platelet
activation.
The PT test evaluates the integrity of the extrinsic and
common pathwaysand directly measures the activity of
clotting factors VII and X, prothrombin (factor II), and
fibrinogen.
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39. Prothrombin Time (PT) (1)
Automated laboratory instruments measure PT by
recording the time required for the blood to clot
after a reagent (i.e., Tissue thromboplastin) has
been added to the patient’s blood sample.
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40. Coagulation Cascades (1)
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41. International Normalized Ratio
(INR) (1)
Because different labs use different reagents, the PT
results obtained from one reagent cannot be reliably
compared with another reagent.
Therefore, the INR is used as a standard unit to
report the result of a PT test.
The INR is the recommended method to monitor both
the initiation and maintenance of anticoagulant
therapy, most notably warfarin.
Individuals who have normal blood clotting and are not
on anticoagulation therapy should have an INR of 1.
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42. International Normalized Ratio
(INR) (2)
For patients on anticoagulation therapy, the target
INR ( therapeutic range) is usually between 2.0 and
4.0 depending on the indication and other patient-
specific factors.
Outside of the therapeutic range, the higher the INR,
the higher the likelihood of bleeding because the
blood is taking longer to clot.
Conversely, if the INR is lower, there is an increased risk
of developing a clot.
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43. International Normalized Ratio
(INR) (3)
Many factors including medications, diet, alcohol intake,
and certain medical conditions can influence the INR.
The INR is calculated as:
Where,
PTR: Prothrombin Ratio.
ISI: international Sensitivity Index.
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