DISEASES OF IMMUNITY Dr.Ayesha Ahmed
Feb 02, 2016
DISEASES OF IMMUNITY
Dr.Ayesha Ahmed
IMMUNITYIMMUNITYResistance of an organism to infection .Resistance of an organism to infection .
Immune system is the collection of cells and Immune system is the collection of cells and molecules responsible for defending against the molecules responsible for defending against the pathogenic organism.pathogenic organism.
INNATE:INNATE: NATURAL, Native . First line of defenseNATURAL, Native . First line of defense
AQUIREDAQUIRED : Developed by exposure to pathogens, : Developed by exposure to pathogens, antigens. Second line of defenseantigens. Second line of defense
INNATE IMMUNITYINNATE IMMUNITY
BARRIERS: BARRIERS: Epithelial barriers of skin, GIT and respiratory Epithelial barriers of skin, GIT and respiratory tract. Tears, salivatract. Tears, saliva
CELLS:CELLS: Neutrophils, macrophages, Natural killer cells . Neutrophils, macrophages, Natural killer cells .
PLASMAPLASMA PROTEINSPROTEINS: Complement system .: Complement system .
ACQUIRED IMMUNITYACQUIRED IMMUNITYHUMORAL IMMUNE RESPONSES: HUMORAL IMMUNE RESPONSES: Involve the activation of Involve the activation of BB cells cells which produce antibodies.which produce antibodies.AntibodiesAntibodies provide protection against provide protection against extracellular microbes in the blood, extracellular microbes in the blood, mucosal secretions and tissues.mucosal secretions and tissues.
CELL MEDIATED IMMUNE CELL MEDIATED IMMUNE RESPONSESRESPONSES: : Involves the Involves the activation of activation of T T cellscells which identify which identify and destroy the infected cells.and destroy the infected cells.Defense against intracellular Defense against intracellular organism.organism.
HELPER T CELLSHELPER T CELLS:: Aid both Aid both responsesresponsesCYTOTOXIC T CELLS:CYTOTOXIC T CELLS: Destroy the Destroy the infected body cellsinfected body cells
A A primary immuneprimary immune response occurs when the response occurs when the body is first exposed to an antigen .body is first exposed to an antigen .
A A secondary immunesecondary immune response occurs when the response occurs when the same antigen is encountered at later time. It is same antigen is encountered at later time. It is faster and of greater magnitude.faster and of greater magnitude.
CELLS OF THE IMMUNE SYSTEMCELLS OF THE IMMUNE SYSTEM
T LYMPHOCYTEST LYMPHOCYTESB LYMPHOCYTESB LYMPHOCYTES
PLASMA CELLS PLASMA CELLS (MODIFIED B CELLS)(MODIFIED B CELLS)CYTOTOXIC T CELLSCYTOTOXIC T CELLS
ANTIGEN PRESENTING CELLS ANTIGEN PRESENTING CELLS Macrophages, Macrophages, Dendritic cellsDendritic cells
NORMAL IMMUNE RESPONSENORMAL IMMUNE RESPONSE
APCsAPCs Macrophages, Macrophages, Dendritic Cells)Dendritic Cells)
CD4CD4 HelperHelper
CD8CD8 Effector Effector
B-CellsB-Cells Plasma Cells Plasma Cells Antibodies( IgA, D, E, M, G)Antibodies( IgA, D, E, M, G)
IMMUNE SYSTEM DISORDERSIMMUNE SYSTEM DISORDERS
HYPERSENSITIVITY REACTIONSHYPERSENSITIVITY REACTIONS
AUTO IMMUNE DISEASES AUTO IMMUNE DISEASES
IMMUNO DEFICIENCY SYNDROMES IMMUNO DEFICIENCY SYNDROMES
DISORDERS OF THE DISORDERS OF THE IMMUNE SYSTEMIMMUNE SYSTEM
HypersensitivityHypersensitivity• Too muchToo much
ImmunodeficiencyImmunodeficiency• Too littleToo little
AutoimmunityAutoimmunity• MisdirectedMisdirected
AUTO-IMMUNITYAUTO-IMMUNITY
Immunological Tolerance: Immunological Tolerance: Unresponsiveness to self Unresponsiveness to self antigens .antigens .
Failure of Self Tolerance leads to Failure of Self Tolerance leads to Auto immune diseasesAuto immune diseases
Strong genetic PredispositionStrong genetic Predisposition
Often triggered by InfectionsOften triggered by Infections
AUTOIMMUNE DISEASESAUTOIMMUNE DISEASES
A Group of 60 to 80 chronic inflammatory A Group of 60 to 80 chronic inflammatory diseases with genetic predisposition and diseases with genetic predisposition and environmental modulationenvironmental modulation
Prevalence is greater for females than malesPrevalence is greater for females than males
CLASSIFICATION OF AUTOIMMUNE CLASSIFICATION OF AUTOIMMUNE DISEASESDISEASES
Organ SpecificOrgan Specific• Insulin dependent diabetes mellitus (IDDM) - Type IInsulin dependent diabetes mellitus (IDDM) - Type I• Graves’ diseaseGraves’ disease
SystemicSystemic• Systemic lupus erythematosusSystemic lupus erythematosus• Rheumatoid arthritisRheumatoid arthritis
RISK FACTORS FOR RISK FACTORS FOR AUTOIMMUNE DISEASESAUTOIMMUNE DISEASES
GeneticGenetic
FemaleFemale
EnvironmentalEnvironmental
DrugsDrugs
InfectionsInfections
CLASSIC AUTOIMMUNE DISEASESCLASSIC AUTOIMMUNE DISEASES
Systemic Lupus Systemic Lupus ErythematosusErythematosus
Rheumatoid ArthritisRheumatoid Arthritis
SYSTEMIC LUPUS SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)ERYTHEMATOSUS (SLE)
Chronic, multi-system inflammatory disease with Chronic, multi-system inflammatory disease with protean manifestations and remitting courseprotean manifestations and remitting course
Clinical manifestationsClinical manifestations– Musculoskeletal (joint and muscle pain)Musculoskeletal (joint and muscle pain)– Dermatological (malar rash)Dermatological (malar rash)– Renal (glomerulonephritis)Renal (glomerulonephritis)
Female to male ratio of 9:1Female to male ratio of 9:1
Etiology is unknownEtiology is unknown
RHEUMATOID ARTHRITIS (RA)RHEUMATOID ARTHRITIS (RA)
Characterized by inflammation of synovial membrane of Characterized by inflammation of synovial membrane of joints and articular surfaces of cartilage and bonejoints and articular surfaces of cartilage and bone
Female to male ratio of 3:1Female to male ratio of 3:1
IMMUNODEFICIENCIEIMMUNODEFICIENCIESS
Due to impaired function of Due to impaired function of one or more components of one or more components of the immune or inflammatory the immune or inflammatory responses. responses. Problem may be with:Problem may be with:
– B cellsB cells– T cellsT cells– PhagocytesPhagocytes– Complement Complement
componentscomponents
Hallmark: Tendency to develop unusual or recurrent,severe infections.
Deficiencies in T / B cells may lead to recurrent infections by certain bacteria, viruses or fungi .
AIDSAIDSAcquired Immuno Defficiency Acquired Immuno Defficiency
SyndromeSyndrome
EtiologyEtiology:: HIV(HIV(Human immunodeficiency virus)Human immunodeficiency virus)
TransmissionTransmission:: Through direct contact of mucous Through direct contact of mucous membrane or blood stream with a bodily fluid containing membrane or blood stream with a bodily fluid containing HIV, such as blood.HIV, such as blood.Transplacental (mother to child)Transplacental (mother to child)
PathogenesisPathogenesis:: HIV causes AIDS by depleting CD4+ helper T HIV causes AIDS by depleting CD4+ helper T cells.cells.Weakening of Immune System and this Weakening of Immune System and this allows opportunistic infections.allows opportunistic infections.
Clinical FeaturesClinical Features: : Oppurtunistic InfectionsOppurtunistic Infections Conditions that do not normally develop in Conditions that do not normally develop in individuals with healthy immune system.individuals with healthy immune system.Caused by bacteria, viruses, fungi and Caused by bacteria, viruses, fungi and parasitesparasitesHigh incidence of certain tumorsHigh incidence of certain tumors
HYPERSENSTIVITY
Hypersensitivity ReactionHypersensitivity Reaction
Hypersensitivity Hypersensitivity * An immune response resulting in exaggerated reactions * An immune response resulting in exaggerated reactions
harmful to the hostharmful to the host
* There are * There are four typesfour types of hypersensitivity reactions: of hypersensitivity reactions:
Type I, Type II, Type III, Type IV Type I, Type II, Type III, Type IV
* Types I, II and III are * Types I, II and III are antibody mediatedantibody mediated
* Type IV is * Type IV is cell mediatedcell mediated
Hypersenstivity ReactionHypersenstivity Reaction
I (Immediate Hypersensitivity)I (Immediate Hypersensitivity)
II (Antibody Mediated Hypersensitivity)II (Antibody Mediated Hypersensitivity)
III (Immune-Complex Mediated Hypersensitivity)III (Immune-Complex Mediated Hypersensitivity)
IV (Cell-Mediated Hypersensitivity)IV (Cell-Mediated Hypersensitivity)
FOUR Hypersenstivity ReactionsFOUR Hypersenstivity Reactions..
Type Alternate name Often Mentioned disorders Mediators
IAllergic , Immediate
Asthma IgE
IIAntibody mediated
Auto Immune hemolytic Anemia
IgM, IgGComplement
IIIImmune complex mediated
Systemic Lupus Ereythmatosus
IgGComplement
IV Cell mediatedTuberculosisTuberculin Test
T cell
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