THALASSEMIA

Mendelian disorder characterized by a lack

of or decreased synthesis of either α or β

globin chain of HbA

HEREDITARY SPHEROCYTOSIS

Intrinsic defect in red cell membrane

ankyrin deficiency and other skeletal

membrane components

Ankyrin deficiency associated with

reduced stability and loss of membrane

fragments as cells traverse circulation

Moderate splenomegaly

Clinical Course: Treatment is splenectomy

G6PD DEFICIENCY

X-linked

Impaired or deficient enzyme function

which reduce ability of red cells

iMMUNOHEMOLYTIC ANEMIA

Demonstration of the anti-red cell

Antibodies

The antibody is of the IgG type, does

not usually fix complement and is

active at 37 o C

Primary (Idiopathic)

Secondary

The antibodies are IgM and are most

active in vitro at 0 o C to 4 o C; Antibodies

dissociate at 30 o or above;

SICKLE CELL ANEMIA

Structurally abnormal hemoglobin

Substitution of valine for glutamic acid at

the 6 th position of β globin chain

Microangiopathic Hemolytic Anemia -

abnormally narrowed vessels

In DIC, Malignant HPN, SLE, TTP,

Hemolytic-uremic syndrome,

disseminated cancer

See schistocytes, burr, helmet cells,

and triangle cells

IRON DEFICIENCY ANEMIA

Most common nutritional deficiency

Storage pool of Iron: Hemosiderin and

Ferritin

PERNICIOUS ANEMIA

Autoimmune destruction of gastric mucosa

Chronic atrophic gastritis lack of

intrinsic factor

Achlorydia even after histamine

stimulation

Inability to absorb oral dose of

cobalamine – “Schilling

FOLATE DEFICIENCY

Same as B12 deficiency but without

neurologic changes

APLASTIC ANEMIA

Pancytopenia characterized by anemia,

neutropenia and thrombocytopenia

HEMOPHILIA A

X-linked recessive trait; in male and

homozygous female

Reduction in amount or activity of Factor

VIII

VON WILLEBRANDS DISEASE

Autosomal dominant

Characterized by spontaneous bleeding

from mucous membranes; excessive

bleeding from wounds, menorrhagia

Prolonged BT, PTT, normal platelet count,

reduced vWF and Factor VIII levels

May have quantitative or qualitative effects

in vWF

DISSEMINATED INTRAVASCULAR

COAGULATION (DIC)

Acute, subacute, and chronic

thrombohemorrhagic disorder occurring as

a secondary complication in a variety of

disease

Characterized by activation of the

coagulation sequence that leads to

formation of microthrombi throughout the

microcirculation

“Consumptive Coagulopathy”

B.

PERIPHERAL B CELL NEOPLASMS

A. Chronic lymphocytic leukemia/Small

lymphocytic lymphoma

Features:

CLL and SLL are morphologically,

phenotypically and genotypically

indistinguishable; CLL if

>4,000/mm3 blood lymphocytosis

CLL and SLL less common in Asian

countries compared to Western

countries

Tumor composed of lymphocytes

that express CD19, CD20 and CD5

Lymph node effaced by diffuse

proliferation of small lymphocytes

with proliferation centers

Bone marrow involved in 100% of

cases of CLL and in most cases of

SLL

Clinically:

Median age, 60; male > female

Patients are often

asymptomatic or with non-

specific symptoms

Generalized lymphadenopathy

in 50-60% of cases

WBC count slightly increased or

exceed 200,000/mm3

Hypogammaglobulinemia and

AIHA in some patients

Most indolent type of leukemia,

median survival 4-6 years

CLL and SLL may progress to

prolymphocytic transformation

vs Diffuse Large B cell Lymphoma

Features:

20% of NHL, 60-70% of aggressive

lymphoid neoplasms

Median age: 60 years, but wide age

range

5% of childhood lymphoma

Composed of a diffuse proliferation

of large cells 4-5x small

lymphocytes with vesicular nuclei,

prominent nucleoli (centroblastic

or immunoblastic)

Special subtypes:

Immunodeficiency associated

large B cell lymphoma seen in

severe T cell

immunodeficiencies (e.g. end

stage HIV infection), neoplastic

B cells are often latently

infected with EBV

Body cavity large B cell

lymphoma – arise in malignant

pleural or ascitic effusions,

mostly in advanced HIV

infection; tumor cells are

infected with herpes virus 8

Clinically:

Rapidly enlarging node

Extranodal involvement,

common: GIT, skin, bone,

brain, Waldeyer’s ring

Bone marrow involvement

occurs late in the disease

Aggressive tumors that are

rapidly fatal if untreated

With treatment, remission in up

to 80%; cure in 50%

2. PRECURSOR B CELL AND T CELL

NEOPLASMS

Acute lymphoblastic leukemia/lymphoma

Features:

Composed of immature, pre-B and

pre-T cells (lymphoblasts)

85% of ALL are pre-B cell, presents

typically as acute leukemia

15% of ALL are pre-T cell, present

in adolescent males as lymphomas

often with thymic involvement

Most cases occur before age 15,

peak incidence 4 years, male >

female

Must differentiate from AML since

similar signs and symptoms but

different response to chemotherapy

Positive TDT in 95% of cases

90% with numerical and structural

changes in the chromosomes, > 75%

hyperdiploidy

Clinically:

Signs and symptoms related to bone

marrow depression:

Fatigue, pallor – anemia

Fever – infections

Bleeding – thrombocytopenia

Bone pain and tenderness –

marrow expansion and

infiltration of subperiosteum

Neurologic symptoms

(headache, vomiting) –

meningeal spread

Hepatomegaly/splenomegaly –

leukemic infiltrates

90% complete remission, with

chemotherapy; 2/3 cured

Poor prognostic factors (require bone

marrow transplantation)

Less than 2 years of age

Presentation in adolescence or

adulthood

5 jcc

© Spidey Transcriptions

Peripheral blasts greater than

100,000/mm3

Presence of Philadelphia

chromosome t(9;22)

vs Acute Myelogenous Leukemia (AML) –

accumulation of immature myeloid

cells in the bone marrow

affects primarily adults, age 15-39 years

Constiture 20% of childhood leukemias

Revised FAB classification

3. Chronic Myelogenous Leukemia

A disease of adults 25-60 years

90% of cases, karyotype reveals the

Philadelphia chromosome t(9;22)

Morphology:

Peripheral blood: WBC count

generally > 100,000/mm 3 showing

the entire spectrum of myeloid

series; increase include eosinophils,

basophils and platelets;

predominance of neutrophils,

metamyelocytes and myelocytes

Bone marrow: 100% cellular, mostly

maturing granulocytes

LAP: 0 or markedly decreased < 10

(N=13-130); in leukemoid reaction or

other MPDs, LAP is elevated

Chromosome analysis: Philadelphia

chromosome t(9;22) resulting in a

fusion gene tyrosine kinase (BCR-ABL)

Clinically:

Insidious onset, anemia, weakness,

fatigue

Massive splenomegaly (may be the

initial finding)

Poor response to treatment; MS 3

years; 50% go into the accelerated

phase terminating in blastic crisis

(acute leukemia like)

50% go directly to blastic crisis (70%

AML; 30% ALL)

Treatment:

Targeted therapy: tyrosine kinase

inhibitor (Imatinid mesilate) and

newer kinase inhibitors, bone

marrow transplantation, interferon

α

vs Primary Myelofibrosis

A neoplastic transformation of a

multipotent stem cell characterized by

early progression to marrow fibrosis

Fibrosis due to fibrogenic factors

secreted by neoplastic megakaryocytes

Morphology:

Peripheral blood: anemia,

leukoerythroblastic reaction, tear

drop erythrocytes

Bone marrow:

Early: tri-lineage

hypercellularity, minimal

fibrosis

Late: hypocellular with diffuse

fibrosis and clusters of atypical

megakaryocytes

Spleen: extramedullary

haematopoiesis (splenomegaly)

Clinically:

Patients 60 years and above

Present with anemia and massive

splenomegaly

MS: 1-5 years

5-20% transform to AML

4. Hodgkin’s Lymphoma (neoplasm of

Reed Sternberg cells and variants)

HODGKIN’S LYMPHOMA

Originate almost always from a single node

or chain of nodes and spreads to contiguous

nodes

Presence of Reed-Sternberg cells admixed

with a variable inflammatory infiltrate

Associated with systemic manifestations

Neoplastic Reed Sternberg cells are derived

from germinal center or post germinal

center B cells, rarely (1-2%), from

transformed T cells

Classification:

Classic Hodgkin’s Lymphoma (similar

immunphenotype): CD 15 (+), CD 30 (+)

Nodular sclerosis

Mixed cellularity

Lymphocyte rich

Lymphocyte depleted

Lymphocyte predominance – B cell

immunophenotype distinct from the

classic subtypes (arise from germinal

center B-cells) – CD 20 (+), CD 15 (+),

CD 30 (-)

Reed Sternberg cell

Common denominator to all

Neoplastic element of Hodgkin’s Lymphoma

Classic Reed Sternberg cell,

binucleate/bilobed → mirror image with

prominent “owl-eye” nucleoli surrounded

by a clear halo abundant, amphophilic

cytoplasm

Variants: mononuclear, lacunar, L and H

pleomorphic

Must be present to diagnose Hodgkin’s

Lymphoma

nn Arbor staging system for Hodgkin’s disease

Stage 1

Involvement of a single node region or

a single extralymphatic organ or site

Stage 2

Involvement of two or more lymph

node regions on the same side of the

diaphragm or localized involvement of

an extralymphatic organ or site and one

or more lymph node regions on the

same side of the diaphragm

10 jcc

© Spidey Transcriptions

Stage 3

Involvement of lymph node regions on

both sides of the diaphragm which may

also be accompanied by localized

involvement of the spleen or both

Stage 4

Diffuse or disseminated involvement of

one or more extralymphatic organs or

tissues with or without associated

lymph node enlargement

The reason for classifying the patient as

stage 4 should be identified further by

defining the site with symbols (e.g. H+

M+: liver and bone marrow involved)

5.Myelodysplastic Syndrome (MDS) –

associated with ineffective

hematopoeisis and associated

cytopenias

Chronic Myeloproliferative Disorders

(MPD) - associated with increased

production of terminally differentiated

myeloid cells

CML

Polycythemia vera

Essential thrombocytosis

Primary Myelofibrosis

MYELODYSPLASTIC SYNDROMES (MDS)

A clonal stem cell disorder characterized by

maturation defects resulting in ineffective

and disordered haematopoiesis and

increased transformation to AML

2 types:

Idiopathic or primary MDS – affects

patients over 60 years of age and

develops insidiously; MS: 9-29 months

Therapy related MDS (TMDS) – a

complication of previous

myelosuppressive drug or radiation,

about 2-8 years after exposure; poorer

prognosis; MS 4-8 months

Morphology:

Peripheral blood: pancytopenia

Bone marrow: hypercellular,

monocellular or hypocellular with

disordered (dysplastic) differentiation

of 3 lineages (erythroid, myeloid and

megakaryocytic)

< 20% blasts in the bone marrow

Clinically:

Primary MDS affects elderly patient’s

older than 60 years

Weakness, infection haemorrhage

(acute leukemia-like) due to

pancytopenia

50% are asymptomatic and discovered

after accidental blood tests

10-40% of patients progress to AML,

particularly with TMDS

vs CHRONIC MYELOPROLIFERATIVE

DISORDERS (MPDS)

A clonal neoplastic proliferation of

multipotent progenitor cell capable of

giving rise to mature erythrocytes,

platelets, granulocytes and monocytes

except CML in which the pluripotent stem

cell that give rise to lymphoid and myeloid

cells is affected

Common pathogenetic factors: mutated

and activated typosine kinases

Includes:

CML

Polycythemia vera

Essential thrombocytosis

Primary myelofibrosis

Rare: systemic mastocytosis, chronic

eosinophilic leukemia, stem cell

leukemia

Common features:

Neoplastic stem cells have the capacity

to circulate and home to secondary

hematopoietic organs particularly the

spleen giving rise to extramedullary

haematopoiesis therefore varying

degrees of splenomegaly

Frequent occurrence of myelofibrosis

and pancytopenia

Similar clinical and pathologic

manifestation at some stage (overlaps

and transitional forms between types)

All can progress to acute leukemia,

most frequent with CML

Diagnosis is based on correlation

between morphologic findings clinical

and laboratory findings and cytogenetic

studies

c. BRIEFLY DISCUSS THE DISTINCTIVE HISTLOGIC AND CLINICAL BEHAVIORS OF DIFERENT TYPES OF HODKIN DISEASE

D.

IDENTIFY THE FORMULA THAT WILL GIVE YOU THE FOLLOWING

Hemoglobin

RBC ( millions ) x 3 = Hb

Rbc count

RBC ( millions ) x 3 = Hb

RBC ( millions ) x 9 = Hct

Platelet count

10 OIF x 2000 =

platelet count

hematocrit

RBC ( millions ) x 9 = Hct

Mcv

MCV = HCT/RBC count

E. WHAT IS THE NORMAL REFERENCE VALUES FOR THE FOLLOWING

WBC

5-10 x 10 9 /L

PLATELET

150 – 450 x 10 9 /L

RBC

Normal Values:

4.5 – 6.0 x 10 12 / L for men

4.0 – 5.5 x 10 12 / L for women

HEMOGLOBIN

Normal Values:

14 – 18 gm / 100 ml for men

12 – 16 gm / 100 ml for women

*100mL = 1Dl

HEMATOCRIT

Normal Values:

40 – 54 % for men

37 – 47 % for women

F. DEFINE THE FOLLOWING AND IN WHAT CONDITION THEY ARE SEEN

RETICULOCYTE COUNT

Stage after the noromoblast ; nucleus is extruded

with cytoplasmic microsomes or ribosomes which

remain for 1-2 days (appreciated in methylene or

cresyl blue stain)

These cells are anucleated but still contatin

nuclear remnants. On regular stains, you will not

see them hence, you need a special stain.

Large RBC with dark blue dots or thin short

irregular linear structures → Polychromatophilic

(bluish pink), megaloblastic

Measures index of production of mature RBC by

bone marrow (how the bone marrow responds to

changes in blood conditions)

shows polychromatophilia (blue gray hue) on

Wright stain

Normal Values:

0.5 - 1.5 % (anything above 1.5% is increased)

Requested in patients suspected of having

hemolytic anemia or when you suspect an

increase in Rct count.

Most Common Causes of Reticulocytosis

Hemolytic anemia, chronic or acute

Acute bleeding

After treatment of vitamin B 12 / folate / iron

Deficiency

Anisochromia

When there is variety in color – normochromic,

hypochromic, hyperchromic.

This can happen in patients with anemia, or being

treated, or reticulocytosis.

Acanthocytes

Appear similar to crenated erythrocytes.

However, the projections in acanthocytes are

irregularly space. At the apex of the projections

are SHARP POINTS, as contrasted to the smooth

or blunt apices of the crenated RBCs.

Patients with acanthocytes frequently exhibit

metabolic dysfunction.

o This dysfunction is usually associated with

decreased levels of β – lipoproteins (β –

lipoproteinemia) which is a highly

important lipid transporting protein.

Patients with this dysfunction do not

absorb lipid in the small intestines.

Consequently, the feces contain an excess

amount of fat, whereas the plasma and

subsequent cellular levels of lipid are

markedly decreased.

o It is speculated that because an

appreciable constituent of the

corpuscular membrane is lipid in nature,

the decreased lipid levels may account for

the erythrocyte assuming such

configuration.

Howell-Jolly Bodies

remnants of DNA and usually occur singly and on

the periphery of the corpuscle.

Seen in hemolytic anemia, post-splenectomy,

megaloblastic anemia

They are SINGLE INCLUSIONS!

Do NOT mistaken them for platelets because they

can stack on top of your RBCs.

Pappenheimer bodies

These are remnants of iron.

You also need a special stain to see this.

This image was taken from the 1997 Cytohematology Proficiency

Test Event - Slide 005. On Wright stained smears, Pappenheimer

bodies appear as violet staining granules usually found along the

periphery of the red cells, often in clusters. They must be confirmed

with an iron stain. These iron-staining granules are found in sideroblastic and megaloblastic anemias, alcoholism, post-

splenectomy, and in some hemoglobinopathies.

Rouleaux Formation

When you see abnormal stacking of RBC like a

pile of coins.

This can be seen in abnormal protein states like

hypergammaglobulinemia (↑protein in blood)

Seen in multiple myeloma (MM).

o Neoplasm of the plasma cell, but is a

monoclonal type – you produce only one

type: either κ or λ (kappa or lambda).

o It is a malignancy, and these plasma cells

synthesize protein, hence

hypergammaglobulinema → rouleaux.

G. WEN DO YOU REQUEST FOR THE FOLLOWING TESTS? GIVE AT LEAST 2 INDICATIONS

RETICULOCYTE COUNT

Stage after the noromoblast ; nucleus is extruded

with cytoplasmic microsomes or ribosomes which

remain for 1-2 days (appreciated in methylene or

cresyl blue stain)

These cells are anucleated but still contatin

nuclear remnants. On regular stains, you will not

see them hence, you need a special stain.

Large RBC with dark blue dots or thin short

irregular linear structures → Polychromatophilic

(bluish pink), megaloblastic

Measures index of production of mature RBC by

bone marrow (how the bone marrow responds to

changes in blood conditions)

shows polychromatophilia (blue gray hue) on

Wright stain

Normal Values:

0.5 - 1.5 % (anything above 1.5% is increased)

equested in patients suspected of having

hemolytic anemia or when you suspect an

increase in Rct count.

Most Common Causes of Reticulocytosis

Hemolytic anemia, chronic or acute

Acute bleeding

After treatment of vitamin B 12 / folate / iron

Deficiency

BONE MARROW ASPIRATION BIOPSY

To confirm diagnosis of megaloblastic anemia,

leukemia, multiply myeloma (MM)

Diagnosis of bone marrow hypoplasia, aplastic

anemia (a pancytopenia where the entire BM

becomes fatty)

To document deficiency in body iron stores -

reticuloendothelial system (i.e. in retractable

anemia)

To demonstrate metastatic / infectious disease

(i.e. myelophthisic anemias)

Usually done on the iliac crest

Hemoglobin electrophoresis

Hemoglobin Electrophoresis

- Used to detect abnormal hemoglobin

**examples: Hemoglobin S- sickle cell anemia

Hemoglobin H – thalassemia

Hemoglobin A – normal

Used to diagnose Hemoglobinopathy

- A definitive test

Principle:

H b molecules in alkaline solution have a net (-) charge and migrate toward the anode in an

electrophotometric system

**Hemoglobin = heme + globin

globin (protein) is comprised of amino acids having different migration rates and being amphoteric

which can be charged positively or negatively depending on the medium

o Commonly used mediums: cellulose acetate an alkaline medium and citrate agar an

acidic medium

Usage of cellulose acetate an alkaline medium will allow the amino acid to have a net

negative charge that will migrate towards anode

While usage of an acidic medium will let the amino acid have a net positive charge

and migrate toward the cathode

Procedure:

1. Patient’s hemosylate is placed in a cellulose acetate membrane and immersed on buffered solution.

** A hemosylate is prepared from the patient’s blood sample and placed on the cathode side of the

acetate strip because they have a net negative charge in an alkaline solution so that will migrate

toward the positive side.

2. Electric current is applied and allows Hb to migrate different speeds (slow, intermediate, or fast)

Eg. A2 (slowest) < C < S < F < A (fastest)

**Since each of the different hemoglobin’s has distinctly different amino acid contents, and different

hemoglonins migrate along the acetate strip at different rates of speed for a specific pH.

**The speed at which the hemoglobin travels is directly dependent on the net charge (because of the

amino acid content)

**The different kinds of hemoglobin can be differentiated through the differences in the speed of

migration.

3. Upon separation, Hb’s is stained and quantitated.

4. Unknown identified by comparison with known Hb.

Pathology: Special Hematologic Examinations | 6

**By placing the acetate strip in a densitometer, one is able to quantify the different hemoglobin’s

present

**Cellulose Acetate Method is for screening

**Citrate agar method is for confirmation has an acidic medium

Indication:

- To detect and identify abnormal hemoglobin

H. WHAT TEST IS MOST USEFUL FOR EACH OF THE FOLLOWING

Hereditary spherocytosis- Osmotic fragility Test/Incubated Osmotic Fragility Test

Iron deficiency anemia-Bone marrow examination

Hemoglobin s- Hemoglobin Electrophoresis

Staging of lymphoid neoplasm- Bone marrow examination

aplastic anemia- Core Biopsy Bone marrow examination

paroxysmal nocturnal hemoglobinuria (PNH)-Acid serum (Ham’s) test

I. GIVE THE MAJOR IMPORTANT FACTORS REGULATING HEMOSTASIS

Primary Hemostasis

♠ Platelets bind via glycoprotein Ib (GpIb)

receptors to von Willebrand factor (vWF) on

exposed extracellular matrix (ECM)

♠ Platelets are activated, undergoing a shape

change and granule release.

♠ Released adenosine diphosphate (ADP) and

thromboxane A 2 (TxA 2 ) induce additional

platelet aggregation through platelet GpIIb-IIIa

receptor binding to fibrinogen, and form the

primary hemostatic plug.

C. Secondary Hemostasis

♠ Tissue factor (released due to endothelial

injury) and the phospholipid complex

(expressed at the surface of the platelets

stimulate the coagulation cascade

♠ End result fibrin polymerization, “cementing”

the platelets into a definitive secondary

hemostatic plug

J Vitamin K dependent (for the post-translational

carboxylation):

• Factor II, VII, IX, X

K

Intrinsic Pathway

Pathology : Blood Coagulation | 6

Initiated by the Hageman Factor. Factor

XIIXIIa, which uses HMWK (high molecular

weight kininogen) collagen as a cofactor

The end result of the activation of factor XII

is XIXia and prekallikrein kallikrein

Factor XIa subsequently activates factor IX

to XIa. At the same time there is activation of

factor VIII to VIIIa with the help of factor IIa

(thrombin)

common pathway

Triggered by damaged endothelial lining of

blood vessel when it comes in contact with

foreign antibodies

Evaluated by activated partial thromboplastin

time (aPTT) remember Brad PITT

Factors exclusively involved: XII, XI, IX, VIII

♦ Extrinsic Pathway

Secondary to endothelial injury

Tissue injury induces endothelial cells to

express tissue factor (III) thereby activating

factor VII to VIIa

Triggered by tissue thromboplastin (Factor III)

which is released by damaged endothelial and

body tissues

Evaluated by prothrombin time (PT)

remember PET

Factors exclusively involved: III and VII

L. Low fibrinogen levels may be due to the

presence of fibrinolysins or DIC

In DIC, the coagulation cascade and

platelets are activated so there is formation

of clot. At the same time, the body tries to

degrade the clots because there should be

no thrombus. So there are (+) fibrin

degradation products.

Disorder of Fibrinolysis: Disseminated

intravascular coagulation (DIC) – occurs when

there is a liberation of thromboplastin and other

unknown substances into the bloodstream which

results in the deposition of fibrin and fibrin

precursor substances like fibrinogen.

Disorders which can cause DIC

o Obstetric complications

o Infections

o Neoplasms

o Massive tissue injury

o Miscellaneous

♠ Patients with DIC will present with s/sx of

bleeding, acute renal failure, respiratory failure,

tissue hypoperfusion and infarction (because of

thrombosis)

♠ Laboratory

o Decreased platelet levels

(thrombocytopenia)

o High levels of fibrinogen

(hyperfibrinogenemia)

PT and aPTT abnormalities

o Elevated fibrin degradation products

(FDP

M.Thrombotic thrombocytopenic

purpura (TTP) isolated

consumption of platelets but no

consumption of coagulation factors.

• There is an inherent vascular

wall dysfunction resulting in

excessive deposition of platelet

aggregates in the renal and

cerebral vessels.

• Female>male

• Patient presents with:

(Remember FAT RN)

o Fever

Pathology : Blood Coagulation | 4

o Microangiopatic type of

hemolytic anemia

o Thrombocytopenia

o Renal abnormalities

o Neurological abnormalities

Vasculitis

Hemolytic-Uremic Syndrome also

results from consumption of platelets

(like TTP but less pronounced

neurologic symptoms and a more

pronounced renal symptoms)

• Patient presents with:

(Remember FRAT)

o Fever

o Renal abnormalities

o Anemia

o Thrombocytopenia

HELLP Syndrome (Hemolysis,

Elevated Liver enzymes, Low

Platelet count) commonly seen in

toxemia of pregnancy (e.g. pre-

eclampsia) or delivery. Patients

present with microangiopathic

hemolysis

Immune destruction of platelets

Idiopathic thrombocytopenic purpura

(ITP) an immunologic process

(type II): (+)antibodies against

platelet membrane antigens. ITP can

be of two types:

• Acute ITP more common in

children; sudden onset of

thrombocytopenia following an

infection commonly rubella,

chicken pox, toxoplasmosis or

CMV infection. It typically lasts up

to 6 weeks and follows a

spontaneous remission in 8% of

patients. The platelet count may

reach as low as 20,000/mm 3 .

The mechanism is secondary to

attachment of virus to platelet

membrane resulting in the

alteration of the membrane

proteins.

• Chronic ITP slow onset but

long duration. It can last for

months to years. The platelet

count doesn’t drop as severely as

the acute type. The treatment is

usually splenectomy because this

does not result to spontaneous

remission. (*spleen is removed

because the antibody production

cannot be corrected, so the

treatment is by decreasing

sequestration by the spleen

through splenectomy)

Post-transfusion purpura commonly

occurs after platelet transfusion.

Patients develop antiplatelet

antibodies. But this does not occur in

all patients who receive platelet

transfusion

Drug-induced Ab formation follows

the same principle as ITP. The drug

alters the membrane proteins of the

platelets. Drugs: quinolone and

heparin

COAGULATION FACTORS

Factor I (fibrinogen)

Factor II (prothrombin)

Factor V (labile factor)

Factor VII (stable factor)

Factor VIII (vWF complex)

Factor IX (plasma thromboplastin)

Factor X (Stuart)

Factor XI

Factor XII (Hageman)

Factor XIII (fibrin stabilizing factor)

High-Molecular Weight Kininogen (HMWK;

Fitzgerald factor)

Prekallikrein (Fletcher, PK)

COAGULATION FACTORS

o Factor I (fibrinogen) – synthesized in the liver

so it is decreased in liver damage/disease. It is

an acute phase reactant. It is the final major

step in the coagulation pathway

Acute Phase reactants are substances

which are elevated in immunologic process

but not involved in the reaction. They are

elevated in response to trauma or to onset

of variety of illnesses

o Factor II (prothrombin) is a proenzyme

synthesized also by the liver and is decreased

in liver disease. It becomes thrombin when

activated. It is Vitamin K-dependent. Deficiency

in prothrombin is extremely rare but if it occurs it

is an autosomal recessive trait

o Factor V (labile factor) is also synthesized by

the liver. It is found in plasma, but not serum. It

must be frozen to maintain activity

(labileunstable). Deficiency: Parahemophilia

(associated with bruising and soft tissue

hemorrhage)

o Factor VII (stable factor) is also synthesized

by the liver and Vitamin K dependent. It is found

in both serum and plasma. Deficiency in Factor

VII is inherited as an autosomal recessive trait.

Patients with presents with hemarthroses, large

hemorrhages (in joints, body cavity, intracranial

and intramuscular sites), and delayed post-

surgical bleeding.

o Factor VIII (vWF complex) has 2 subunits:

VIIIR (vWF) and VIIIC (antihemophilic factor)

VIIIC is synthesized by the liver and

deficiency is inherited as an X-linked trait.

The deficiency results to Hemophilia A

• Classic Hemophilia: most

common congenital

COAGULATION FACTOR

DEFICIENCY. Patients presents

with severe bleeding following even

minor trauma, hemarthroses

(bleeding in the joints), mouth, oral

cavity, GIT, intracranial

hemorrhages. Low VIIIC activity,

vWF are normal, normal PT and

bleeding time, aPTT is abnormal

VIIIR is synthesized by endothelial cells,

megakaryocytes and platelets. It has a role

in platelet adhesion and aggregation. The

deficiency in vWF (VIIIR) is called von

Willebrand’s disease

• Willebrand’s disease is an

autosomal dominant trait. Most

common congenital BLEEDING

DISORDER. If there is a decreased

vWF levels there is also a decrease

in VIIIC levels because VIIIR is a

carrier of VIIIC

Factor IX (plasma thromboplastin) is found in

the serum or plasma. It is also Vitamin K

dependent. Its deficiency is inherited as an X-

linked recessive trait. The deficiency is called

Christmas disease or Hemophilia B. Patients

will present with a hemophilia like symptoms

o Factor X (Stuart) is found in the serum and

plasma. It is part of the final common pathway.

It is also vitamin K dependent

o Factor XI

o Factor XII (Hageman) is the surface contact

activator for intrinsic pathway

Deficiency does not cause bleeding, only

increased thrombotic incidence (MI and

thrombosis).

o Factor XIII (fibrin stabilizing factor) The

deficiency is inherited as an autosomal

recessive trait. Infants with the disease present

with bleeding at the umbilical stump. This is

also associated with intracranial hemorrhage,

soft tissue hemorrhage, recurrent abortions and

delayed or poor wound healing. aPTT, PT and

bleeding time are normal. The only way to

diagnose is the 5M-urea clot dissolution

time This measures the time it takes for a clot

to dissolve in urea (normal: 24 hrs; abnormal:

<24 hrs).

o High-Molecular Weight Kininogen (HMWK;

Fitzgerald factor) is part of the kallikrein

system. It converts factor XII to XIIa. The

deficiency of this factor is rare and does not

produce clinical bleeding

o Prekallikrein (Fletcher, PK) – complexes with

HMWK, kallikrein precursor, cleaved by Factor

XIIa (Activated Hageman) to produce kallikrein.

Its deficiency does not produce clinical bleeding

o REMEMBER

9 out of 13 factors are proenzymes and must

be activated except fibrinogen (not an

enzyme), Factor III (a complex rather than a

single protein), Factor IV (Calcium)

Vitamin K dependent (for the post-translational

carboxylation):

• Factor II, VII, IX, X

Many of the factors are decreased at birth

except fibrinogen and platelets (normal level).

Factor VIIIC and VIIIR (vWF) are elevated at

birth. Since many factors are decreased at

birth, PT and aPTT cannot be used in

newborns

Acute phase reactants: Factor VIII, Fibrinogen

(their levels are usually elevated during

inflammation)

O.PLASMA WBC, RBC

P

Q. Blood screening tests

- ABO typing, Rh typing, VDRL; venereal disease

research laboratory test (syphilis), malarial smear,

HBsAg; surface antigen of hepatitis B virus, HCV;

hepatitis C virus, HIV

R.

Transfusion Reactions

- Adverse symptoms produced by red cell

incompatibility between a patient and a unit of

donor blood

- Causes of fatal reactions, most of which are due to

clerical errors: misidentification of patients;

mislabeling of blood samples; error in laboratory

records; mistakes in blood typing; inaccurate

antibody screening or cross matching

- Could wither be acute/delayed,

hemolytic(intravascular or extravascular)/non-

hemolytic, immune/n on-immune

- Types of Transfusion Reactions

a. Acute – occurs within minutes to 24 hours of

the transfusion

b. Delayed – develop within days to months or

even years after the transfusion; sometimes

even on subsequent transfusion

- Factors that influence whether a transfusion will

be acute/delayed:

a. Number of incompatible red cells infused

b. Antibody class or subclass

c. Achievement of optimal temperature for

binding