Diseases of the Immune System - Nelson Flashcards Preview

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Flashcards in Diseases of the Immune System - Nelson Deck (40):
1

What are the two branches of the Adaptive Immune System?

Humoral Immunity
Cellular Immunity

2

What is the function of the immune system?

To protect against harmful microorganisms and cellular agents (malignant cells)

3

Define Immunodeficiencies

Disorders with decrease or loss of immune function, either acquired or congenital

4

What are Hypersensitivity Reactions and what are the 2 types of having TOO MUCH immunity?

Disorders with pathologic immune responses or reactions
Allergic Reactions
Autoimmune Reactions

5

Type I Hypersensitivity

Too much IgE crosslinking in response to environmental antigen leading to mast cell and basophil release of histamine, causing synthesis of prostaglandins and leukotreines, such as hay fever, asthma, hives, food allergies, and eczema.

6

Type II Hypersensitivity

IgG or IgM Mediated Autoimmunity due to antibodies that react against self, such as hemolytic disease of maternal antibodies reacting to fetal RBCs, Myasthenia Gravis (AChR antibodies), and Good Pasture's Syndrome (Basement membrane antibodies causing nephritis).

7

Type III Hypersensitivity

Immune complexes of antigen and antibody that get stuck in small vessels, such as the kidneys, joints, pleura and skin. Complement is activated to respond to the antigen-antibody complex and healthy tissues are destroyed in the process, which happens in Lupus (making antibody to own DNA) and RA (making antibody to antibody); serum sickness, necrotizing vasculitis.

8

Type IV Hypersensitivity

Cell-mediated hypersensitivity caused by activated CD4+ Th1 T-Cells (autoimune or innocent bystander injury); Contact hypersensitivity, TB reactions, Granulomatous hypersensitivity

9

Humoral Immunity

B-cells that protect extracellular spaces release antibodies into bodily fluids.

10

Cell-Mediated Immunity

T-cells that survey surfaces of cells, looking for mutated cells or parasites.

11

Define Innate Immunity

Pre-existing defense mechanisms present prior to infection

12

Define Adaptive Immunity

Reactive immune mechanisms that are stimulated by microbes or other foreign antigens

13

Function of B Lymphocytes

Neutralization of microbe, phagocytosis, complement activation

14

Function of Helper T Lymphocytes (CD4+)

Activation of macrophages
Inflammation
Activation (proliferation and differentiation) of T and B lymphocytes

15

Function of Cytotoxic T Lymphocytes (CD8+)

Killing infected cells

16

Function of Regulatory T Lymphocytes

Suppression of Immune Response

17

Function of Natural Killer cells

Killing infected cells

18

Define Generative (Primary) Lymphoid Organs

Sites where T (Thymus) and B (Bone Marrow) lymphocytes mature

19

Define Peripheral (Secondary) Lymphoid Organs

Site where the adaptive immune response is initiated (lymph nodes, spleen)

20

Class I MHC Molecules

coded by HLA-A, HLA-B, and HLA-C genes and display antigens to CD8+ T-cells and NK cells

21

Class II MHC Molecules

coded by HLA-DP, HLA-DQ, HLA-DR genes and display antigents to CD4+ T-cells

22

What are two uses for HLA testing?

1) determine disease risk
2) transplantation workup

23

What is light chain restriction?

Monoclonal B-cells typically express only one type of immunoglobulin, either kappa or lambda.

24

How can monoclonal light chain restriction be detected?

Flow cytometry - should be 1.5 kappa to lambda
Serum protein electrophoresis
Immunofixation electrophoresis
Kappa and lambda in situ hybridization - staining looking for proportions

25

What are the 5 pillars of cancer treatment?

Surgery
Chemotherapy
Radiation Therapy
Molecular Targeted Therapy
Imatinib and Trastuzumab
Target cancer cells by homing in on specific molecular changes seen primarily in those cells
Immunotherapy
T-cells to attack the tumor

26

Define Hypersensitivity Reactions

Sensitization to previous exposure to antigen and when re-exposed, pathologic immune reactions ensue with excessive, injurious reaction to the antigen

27

What does a hypersensitivity reaction usually result from?

Imbalance between effector mechanisms of immune response and control mechanism to limit response

28

What do eosinophils release in a type I hypersensitivity reaction?

Major Basic Protein and Eosinophil Cationic Protein = Toxic to epithelial cells

29

Define Atopy

Predisposition of developing immediate hypersensitivity reactions; 50% correlated with positive family history; higher serum levels of IgE and more Il-4 producing Th2 cells

30

Describe the immediate type I hypersensitivity reaction

Exposure to allergen --> Th2 response and IgE production --> IgE binds to Fc on Mast Cells --> Re-exposure to allergen leads to mast cell degranulation

Causes: Vasodilation
Vascular Leakage
Smooth Muscle Spasm

31

Describe the late phase type I hypersensitivity reaction

Eosinophil infiltration with neutrophils and T-cells

Causes: Leukocyte Infiltration
Epithelial Damage
Bronchospasm

32

Describe immediate hypersensitivity reactions with non-atopic allergies

Exercise or temperature induced, not mediated by T-cells or IgE

33

Immediate Type I Hypersensitivity Systemic Anaphylaxis

Life threatening systemic allergic reaction with falling BP, vascular shock, bronchospasm, laryngeal edema and difficulty breathing due to massive mast cell activation

34

What are the two mechanisms for T-cell Mediated Type IV Hypersensitivity?

CD4+ T-Cell Mediated Inflammation
CD8+ T-Cell Mediated Cytotoxicity

35

Define Graulomatous inflammation

A distinctive pattern of chronic inflammation via strong activation of T-cells leading to activated macrophages resulting in tissue injury.

36

What is a granuloma?

A focus of chronic inflammation consisting of a microscopic aggregation of macrophages that are transformed into epithelial-like cells called histiocytes; may also fuse to form multi-nucleated giant cells

37

What causes granulomas to form?

Immune reactions or reaction to foreign material

38

Foreign Body Granulomas

See foreign material within histiocytes or giant cells

39

Caseating Granulomas

Granulomas that induce cell-mediated immune response with central necrosis; usually associated with infection (mycobacterial and fungal infections)

40

Non-Caseating Granulomas

Granulomas that induce cell-mediated immune response without central necrosis (sarcoidosis, Crohn's disease)