Blood Week 9 Dr. Walid Daoud, A. Professor. White Blood Cells (Leukocytes)...

BloodBlood

Week 9Week 9

Dr. Walid Daoud,Dr. Walid Daoud,

A. ProfessorA. Professor

White Blood Cells (Leukocytes)White Blood Cells (Leukocytes)________________________________________________________

Total leukocytic count = 4,000-11,000/mmTotal leukocytic count = 4,000-11,000/mm33

ClassificationClassification::

1. Granular leukocytes:1. Granular leukocytes:

- Neutrophils.- Neutrophils.

- Eosinophils.- Eosinophils.

- Basophils.- Basophils.

2. Agranular leukocytes:2. Agranular leukocytes:

- Monocytes.- Monocytes.

- Lymphocytes.- Lymphocytes.

White Blood Cells (Leukocytes)White Blood Cells (Leukocytes)________________________________________________________Formation of Leukocytes (Leukopoiesis)Formation of Leukocytes (Leukopoiesis)::

All in bone marrow except lymphocytes in All in bone marrow except lymphocytes in lymphoid tissues (LN, thymus & spleen)lymphoid tissues (LN, thymus & spleen)..

Pluripotent stem cellsPluripotent stem cells↓ ↓

Colony forming unit-granulocyte-monocyteColony forming unit-granulocyte-monocyte ↓ ↓ GM-CSFGM-CSF↓ ↓

Myeloid line Lymphoid lineMyeloid line Lymphoid line - - Granulocytes LymphocytesGranulocytes Lymphocytes

- - MonocytesMonocytes


Functions of Granular LeukocytesFunctions of Granular Leukocytes::

11--Neutrophils (60-70%)Neutrophils (60-70%)::

The 1The 1stst line of defense against organisms line of defense against organisms..

a- Marginationa- Margination..

b- Diapedesisb- Diapedesis..

c- Amoeboid movementc- Amoeboid movement..

d- Chemotaxisd- Chemotaxis..

e- Phagocytosise- Phagocytosis..


22 - -Eosinophils (2-6%)Eosinophils (2-6%)::

a- They kill parasitesa- They kill parasites..

b- They increase in allergic conditionsb- They increase in allergic conditions..

c- Weak phagocytosis and show chemotaxisc- Weak phagocytosis and show chemotaxis

33 - -Basophils (0-1%)Basophils (0-1%)::

a- Contain histamine and heparina- Contain histamine and heparin..

b- Possess IgE receptors on their membranesb- Possess IgE receptors on their membranes


Functions of Agranular LeukocytesFunctions of Agranular Leukocytes::

11--Monocytes (2-8%)Monocytes (2-8%)::

a- Become tissue macrophage (RES)a- Become tissue macrophage (RES)..

b- Migrationb- Migration..

c- Phagocytosisc- Phagocytosis..

22--Lymphocytes (20-30%)Lymphocytes (20-30%)::

Immune functionImmune function..

Pathological Variation in Leukocytic CountPathological Variation in Leukocytic Count____________________________________________________________________________

Leukopenia: LeukocytosisLeukopenia: Leukocytosis::

--Chronic infection. -After meal, duringChronic infection. -After meal, during

--Drugs. Exercise and stress. Drugs. Exercise and stress. -Starvation. -Inflam., M. infarction-Starvation. -Inflam., M. infarction

AgranulocytosisAgranulocytosis::

--Exposure to gamma raysExposure to gamma rays..

--DrugsDrugs..

ImmunityImmunity________________________________________________________It is the ability of the body to resist almost all It is the ability of the body to resist almost all types of organisms and toxinstypes of organisms and toxins..

11--Innate (non-specific) immunityInnate (non-specific) immunity::

. .Resistance of skin to invasion by organismResistance of skin to invasion by organism..

. . Destruction of organism by gastric HClDestruction of organism by gastric HCl..

. . PhagocytosisPhagocytosis..

22--Acquired (specific) immunityAcquired (specific) immunity::

. .Humoral immunity: B-lymphocytesHumoral immunity: B-lymphocytes..

. . Cellular immunity: T-lymphocytesCellular immunity: T-lymphocytes..

AntigensAntigens________________________________________________________

They are substances that are able to induce They are substances that are able to induce an immune response & to react specifically an immune response & to react specifically with its productswith its products..

They possess certain chemical structures They possess certain chemical structures specific to them known as antigenic specific to them known as antigenic

determinants, molecular weight > 10,000determinants, molecular weight > 10,000 . .

Antigenic determinants are present on cell Antigenic determinants are present on cell membranes or free e.g., bacterial toxinsmembranes or free e.g., bacterial toxins..

Development of Immune SystemDevelopment of Immune System________________________________________________________I-Origin of lymphocytesI-Origin of lymphocytes::

In fetus, lymphocytic stem cells formed inIn fetus, lymphocytic stem cells formed in bone marrow migrate eitherbone marrow migrate either::

. . To thymus glandTo thymus gland to give T-lymphocytes or to give T-lymphocytes or . . To bursa-equivalent tissuesTo bursa-equivalent tissues (liver & spleen)(liver & spleen)

to give B-lymphocytes to give B-lymphocytes..II-Processing of lymphocytesII-Processing of lymphocytes::

11 - -RecognitionRecognition.. 22 - -SpecificationSpecification..

Development of Immune SystemDevelopment of Immune System________________________________________________________

III-Lymphocyte migrationIII-Lymphocyte migration::

They migrate to live in lymphoid tissues as They migrate to live in lymphoid tissues as lymph nodes, spleen, liver & bone marrow lymph nodes, spleen, liver & bone marrow . .

Types of lymphocytesTypes of lymphocytes::

11 - -B-lymphocytesB-lymphocytes..

22 - -T-lymphocytesT-lymphocytes..

33 - -Non B non T-lymphocytes (NK cells)Non B non T-lymphocytes (NK cells)

Development of Immune SystemDevelopment of Immune System________________________________________________________

Varieties of B-lymphocytesVarieties of B-lymphocytes::

- -Plasma cellsPlasma cells . .

- -Memory cellsMemory cells..

Varieties of T-lymphocytesVarieties of T-lymphocytes::

- -Cytotoxic (Killer) T-cellsCytotoxic (Killer) T-cells..

- -Helper T-cellsHelper T-cells..

- -Suppressor T-cellsSuppressor T-cells..

- -Memory T-cellsMemory T-cells..

Major Histocompatibility Complex (MHC)Major Histocompatibility Complex (MHC)______________________________________________________________________

It is a protein on cell membrane genetically encoded It is a protein on cell membrane genetically encoded by chromosome 6. Two classesby chromosome 6. Two classes::

. .MHC class I protein:MHC class I protein: on all nucleated cells on all nucleated cells..

. .MHC class II protein:MHC class II protein: on antigen presenting cells, on antigen presenting cells, mostly macrophages mostly macrophages . .

MHC proteins are specific for individual and MHC proteins are specific for individual and distinguish self from non-self distinguish self from non-self . .

Cellular immune response occurs when foreign Cellular immune response occurs when foreign antigen and MHC protein are coupled and antigen and MHC protein are coupled and presented together to the immune systempresented together to the immune system..

Cellular ImmunityCellular Immunity________________________________________________________

--Done by activated cytotoxic T-lymphocytesDone by activated cytotoxic T-lymphocytes..--It occurs on exposure toIt occurs on exposure to::

..Viruses, fungi, few bacteria e.g. TBViruses, fungi, few bacteria e.g. TB....Cells from other individuals (tissue transplant)Cells from other individuals (tissue transplant)

..Tumor cellsTumor cells..When cytotoxic T-cells are activated they proliferate When cytotoxic T-cells are activated they proliferate and differentiate into clones ofand differentiate into clones of::

11--Activated cytotoxic T-cellsActivated cytotoxic T-cells..22--Memory T-cellsMemory T-cells..

Humoral ImmunityHumoral Immunity________________________________________________________

Produced by B-lymphocytesProduced by B-lymphocytes..

Mainly acts against bacterial infectionsMainly acts against bacterial infections..

Activated B-lymphocytes specific to antigen Activated B-lymphocytes specific to antigen differentiate intodifferentiate into::

11--Plasma cellsPlasma cells..

22--Memory B-cellsMemory B-cells..

Mechanism of Action of AntibodiesMechanism of Action of Antibodies______________________________________________________________

A. Direct attack of antigenA. Direct attack of antigen::

11 - -Agglutination of bacteriaAgglutination of bacteria..

22 - -Precipitation of antigenPrecipitation of antigen..

33 - -LysisLysis..

44 - -OpsonizationOpsonization..

B. Activation of the complement systemB. Activation of the complement system..

Nature and Structure of AntibodiesNature and Structure of Antibodies__________________________________________________________Antibodies are Antibodies are γγ globulins (immunoglobulins) globulins (immunoglobulins)::

IgG, IgM, IgA, IgE and IgDIgG, IgM, IgA, IgE and IgD

Antibody is formed of light and heavy Antibody is formed of light and heavy polypeptide chains bound together by polypeptide chains bound together by disulphide (S-S) bonds known as disulphide (S-S) bonds known as heavy-light chain pairs. Each pair is heavy-light chain pairs. Each pair is bound to another by interchain bound to another by interchain disulphide bridgesdisulphide bridges..

Classes of AntibodiesClasses of Antibodies________________________________________________________

--Immunoglobulin G (IgG)Immunoglobulin G (IgG)..

--Immunoglobulin M (IgM)Immunoglobulin M (IgM)..

--Immunoglobulin A (IgA)Immunoglobulin A (IgA)..

--Immunoglobulin E (IgE)Immunoglobulin E (IgE)..

Undesirable Consequences of Undesirable Consequences of Immune ResponseImmune Response

________________________________________________________

11--Graft rejectionGraft rejection..

22--Auto-immune diseasesAuto-immune diseases..

33--Acquired immune deficiency syndromeAcquired immune deficiency syndrome

) ) AIDSAIDS ( (

Blood GroupsBlood Groups________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

ABO SystemABO System::

A and B antigens on red cell membraneA and B antigens on red cell membrane

))agglutinogenagglutinogen.(.( Antibodies in plasma Antibodies in plasma (agglutinins).(agglutinins). According to presence or absence of A and B According to presence or absence of A and B antigens, humans are divided into 4 blood groupsantigens, humans are divided into 4 blood groups::

B. groupB. groupAgglutinogenAgglutinogenAgglutininAgglutinin%%

AA

BB

ABAB

OO

AA

BB

A and BA and B

--

anti Banti B

anti Aanti A

--

Anti A and anti BAnti A and anti B

40%40%

10%10%

5%5%

45%45%

Importance of Blood GroupsImportance of Blood Groups________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

11--Medicolegal importanceMedicolegal importance:: Determination of blood group can confirm Determination of blood group can confirm

that a certain man is that a certain man is notnot the father of a the father of a specific child, but not that he is. That is a specific child, but not that he is. That is a good negativegood negative..

22--Incompatible blood transfusionIncompatible blood transfusion:: Donor RBCs are agglutinated by recipient Donor RBCs are agglutinated by recipient

plasma but donor serum rarely agglutinate plasma but donor serum rarely agglutinate recipient RBCs. Therefore recipient RBCs. Therefore::

Group O is a universal donorGroup O is a universal donor.. Group AB is a universal recipientGroup AB is a universal recipient..

Blood GroupsBlood Groups__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

__

Rh SystemRh System::

Rh factor is agglutinogen on RBCs (D antigen) Rh factor is agglutinogen on RBCs (D antigen) in 85% of white population (Rh-positive) in 85% of white population (Rh-positive) while who do not have (Rh-negative)while who do not have (Rh-negative)..

Antibody against Rh agglutinogen (anti D) Antibody against Rh agglutinogen (anti D) normally not present in plasma and formed normally not present in plasma and formed only when Rh-ve individual receives Rh+ve only when Rh-ve individual receives Rh+ve bloodblood..

Importance of Rh FactorImportance of Rh Factor__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

__

11--Blood transfusionBlood transfusion::

If Rh-ve individual receives Rh+ve bloodIf Rh-ve individual receives Rh+ve blood..

22--Erythroblastosis fetalisErythroblastosis fetalis::

When Rh-ve female marries Rh+ve male When Rh-ve female marries Rh+ve male leading to kernicterus of fetus leading to kernicterus of fetus..

PreventionPrevention::

- - Anti D antibodies given to mother after Anti D antibodies given to mother after delivery to neutralize Rh antigen delivery to neutralize Rh antigen..

- - Rh-ve person should never receive Rh+ve blRh-ve person should never receive Rh+ve bl..

Blood TransfusionBlood Transfusion________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

IndicationsIndications::

11--To restore blood volume as in hemorrhageTo restore blood volume as in hemorrhage

22--To restore certain blood elementsTo restore certain blood elements::

RBCs in anemia, WBCs in leukopenia, RBCs in anemia, WBCs in leukopenia, platelets in purpura, clotting factors in platelets in purpura, clotting factors in hemophilia, antibodies in infection, plasma hemophilia, antibodies in infection, plasma proteins in hypoproteinemiaproteins in hypoproteinemia..

33--In erythroblastosis fetalisIn erythroblastosis fetalis..

Dangers of incompatible blood transfusionDangers of incompatible blood transfusion..

Blood Week 9 Dr. Walid Daoud, A. Professor. White Blood Cells (Leukocytes)...

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