Class 3

Question 1

Adaptive Immunity

Answer 1

3rd line of defence (1st = skin, 2nd = inflammatory response)
Involves specificity (memory B cells), Memory (MHC), Inducibility (Immunization) & self-tolerance

Question 2

T cells

Answer 2

mediate cellular immunity

Question 3

B cells

Answer 3

produce antibodies (immunoglobulins A, D, E, G, M) that are dumped into plasma & mediate humoral immunity

Question 4

Immunosuppression

Answer 4

Weakened response

Question 5

Hypersensitivity

Answer 5

exaggerated response (inappropriate response to antigen)

Question 6

Alloimmunity

Answer 6

Rejection of other person’s tissues
Ex: transplant, transfusion.
Hyperacute rejection: pt already has antibodies to antigens of organ (quick response)
Acute Rejection: marcophages & phagocytes attack antigen (not as fast)
Chronic Rejection: gradual loss of function of organs due to attack accumulation over the years

Question 7

Stress directly influences immunity through…

Answer 7

Hypothalamic & endocrine hormones and neurotransmitters from ANS (epinephrine & norepinhephrine)
Receptors for all these compounds are found on immune cells in spleen & lymphoid tissue.

Question 8

Autoimmunity

Answer 8

Attacking of one’s own tissues

Question 9

Immune System Response to Stress

Answer 9

• Increase of glucocorticoids & catecholamines (epi/norepinephrine) secretion during stress.
• This increase results in decreased cellular immunity (T-cells, NK & macrophages)by suppressing T-helper cells
• Increase humoral immunity (B-cells) by stimulating T-helper 2 cells
• Increase acute inflammation locally
• Atrophy of thymus & lymphnodes

Question 10

Immune Deficiencies

Answer 10

Failure of immune mechanisms of self-defense

• Primary (congenital): genetic anomaly, single gene mutation that is not inherited
• Secondary (acquired): caused by aftermath of a previous illness

Question 11

Causes of Secondary Deficiencies

Answer 11

Aging
Psychologic stress
Malnutrition
Malignancies
Trauma
Medical treatments
Infections
AIDS***Most common example
     -Complications of other conditions.

Question 12

AIDS Secondary Deficiencies

Answer 12

Bone cancers (b/c bone marrow provides WBC)
Chemotherapy & radiation reactions
(kills cancer & stem cells in bone marrow)
Cause = HIV

Question 13

Immune Deficiencies Manifestations

Answer 13

Recurrent, unusual severe infections (Phagocytic & Complement deficiencies –> can’t fight pus-forming bacteria)
B cell deficiencies (Humoral) then recurrent bacterial infections
T cell deficiencies (Cellular) then causes viral, fungal & atypical infections

Question 14

Immunodeficiencies Treatments

Answer 14

Gamma Globulin Therapy (inject antibodies for a specific infection from plasma of 1 person to another)
Transplantation/Transfusion (Blood)

Question 15

Primary Immunodeficiency

Answer 15

Rare
B-Lymphocyte deficiency: low levels of immunoglobulins (hypgammaglobulinemia) or no immunoglobulins
(agammaglobulinemia)
- Selective IgA deficiency (decreases levels of IgA)
- Bruton agammaglobulinemia (blocked development of mature B cells, resulting in repeated infections, inability to synthesize antibodies) –>X-linked disorder, frequent ear & resp infections

T-Lymphocyte Deficiency:antibody production is diminished due to no T- cells to develop B cells

       - Chronic mucocutaneous candidiasis (T cells can't respond to specific infection agent (C. albicans) --> C.albicans
       - DiGeorge Syndrome (thymic aplasia/hypoplasia, parathyroid gland development diminished, thymus can't produce T cells which activate B cells & low Ca2+ levels & results in tetany & rigidness

Question 16

Complement Deficiencies

Answer 16

Congenital deficiency
Risk for recurrent life-threatening infections at early age
Associated with Neisseria genus (meningitis/gonorrhea)

Question 17

Phagocytic Deficiencies

Answer 17

Chronic granulomatous disease (defect in mechanism of killing bacteria)

Question 18

AIDS

Answer 18

Caused by HIV (retrovirus) which depletes CD4 T-helper cells

Transmitted via sex, blood, placenta, breastfeeding (more cases in women than men)

Question 19

HIV Retrovirus Pathogenesis Mechanism

Answer 19

Viral genetic info is in form of RNA
Reverse transcriptase converts RNA into DNA
Integrase (from virus) inserts new DNA into affected cell’s genetic material

Question 20

HIV Clinical Manifestations

Answer 20

Early symptoms: serologically negative (no antibodies) OR serologically positive (antibodies for HIV) but asymptomatic OR early stages of HIV (Flu symptoms)OR AIDS
Decrease of CD4+ T cell numbers
Diagnosis is made in association with other clinical conditions such as opportunisitic infections or cancer

Question 21

AIDS Risk Factors

Answer 21

Unprotected sex

Question 22

AIDS Treatment

Answer 22

HIghly active antiretroviral therapy (makes it a chronic condition)
Includes protease inhibitors & reverse transcriptase inhibitors
Vaccine?

Question 23

Hypersensitivity

Answer 23

Altered immunologic response to an antigen that results in disease or damage to host
Allergy (effects of hypersensitivity to environmental antigens)
Autoimmunity (disturbance in immunologic tolerance of self-antigens)
Type I
Type II
Type III
Type IV

Question 24

Type I Hypersensitivity

Answer 24

IgE mediated (body is sensitive to this antigen, after second exposure to antigen, mast cells rupture releasing histamine)
Histamine causes increased permeability in vessels, vasodilation, constriction of lungs & increased GI tract peristalsis (nausea)
Involves allergies
Treat with antihistamines
Manifestations: itching, rash, conjunctivites, rhinitis, edema, cramps

Question 25

Anaphylactic Reaction

Answer 25

Type I Hypersensitivity
Genetic predisposition (more mast cells than average)
Extreme allergic reaction (Hives, itchy, wheezing, difficulty breathing, hypotension, tachycardia, GI effects
Treated with Adrenaline, corticosteroids (decrease inflammation in airways) & antihistamines

Question 26

Type II Hypersensitivity

Answer 26

Tissue specific (certain tissue is target for immune response)
IgG & IgM (Cell may be destroyed via antibody & complement causing lysis of cell)
Cell destruction can be caused through phagocytosis by macrophages from antibodies 
Hemolytic Disease (Newborn): baby develops jaundice, Mom = Rh- Baby = Rh +, worst during the second baby because antibodies to blood are developed

Question 27

Type III Hypersensitivity

Answer 27

Immune Complex Mediated 
Antibody binds to soluble antigen in the blood and this complex is deposited into tissue (usually kidneys)
Serum sickness (complexes deposited in bvessels, joints, kidneys) Ex: Raynaud phenomen temperature dependentdeposition --> Cryoglobulins
Arthus reaction (antigen is under skin and forms inflammation response, lesions_

Question 28

Type IV Hypersensitivity

Answer 28

Cytotoxic T lymphocytes (directly kill antigen) or Lymphokine producing T-helper1 cell mediated (produce cytokines that activate phagocytic cells for destruction)
Ex: acute graft rejection, TB skin test, contact allergic reactions

Question 29

Autoimmunity

Answer 29

Breakdown of tolerance, body recognizes self-antigens as foreign
Cause not understood
Ex: Hasimoto’s Thryoiditis (destruction of thyroid gland) & Systemic Lupus erythematosus

Question 30

Systemic Lupus Erythematosus (SLE)

Answer 30

Chronic multisystem inflammatory disease
Auto-antibodies form against nucleic acids*, erythrocytes, coagulation proteins, phospholipids, lymphocytes, platelets…
Deposition of circulating immune complexes containing antibody & host DNA
10X more common in females
Clinical manifestations: Arthralgias/arthritis, rash (Malar/Butterfly rash on face), renal disease, hematologic changes, cardiovascular disease

Question 31

Immunosuppressive Techniques

Answer 31

Corticosteroids (suppress immune response)
Cytotoxic drugs (destroys lymphoid tissue to suppress immune response)
Anti-lymphocyte Serum (destroys only sensitized T-cells that are about to destroy transplanted organ)
Prevent Transplant Rejection by tissue typing (HLA- A, B, C, D)