Immunopathology of Infectious Diseases Continued

Question 1

What are some defects caused by pathogenic mechanisms?

Answer 1

Induction by physical means
Granulocyte and monocyte defects in movement, phagocytosis or killing or decreased number of cells (neutropenia)
Individual components of complement system
T cells (Di Georges Syndrome)
B cells (Brutons syndrome)
Combined Immunodeficiency (T and B cell ) pathogen

Question 2

Immune Deficiency: Congenital and Acquired include what general categories?

Answer 2

Hereditary complement deficiencies
Defective phagocytes
Immune suppression

Question 3

Consequences of hereditary complement deficiencies include deficiencies of what enzymes?

Answer 3

C1q, C1r, C1s, C4 and C2 are associated with defects in activation of the classic complement pathway
(defects lead to greater susceptibility to pyogenic staphylococcal and strep infections)

Question 4

A deficiency in C3 in the complement pathway leads to what?

Answer 4

leads to defect in activation of both the classic and the alternative pathways, which also results in a higher incidence of pyogenic infections

Question 5

A deficiency of the properdin factors of the complement pathway leads to what?

Answer 5

Impair activation of the alternative pathway predisposes to pyogenic infections

Question 6

Deficiencies of C5 through C9 are associated with what?

Answer 6

with defective cell killing with increased susceptibility to disseminated neisserial infections

Question 7

Consequences of deficiencies in the complement pathways. Factor B binds to C3b on cell surfaces and what happens?

Answer 7

Plasma serine protease D cleaves and activates B-C3b as part of the alternative pathway

Question 8

What factors limit the inappropriate activation of complement?

Answer 8

Factors FI and FH
FH bins to C3b and prevents activation and is a cofactor for FI
FI is a serine protease that cleaves C3b and C4b.

Question 9

What are some features of hereditary angioneurotic edema?

Answer 9

Genetic form of Angioedema, also called Qunike’s disease
Persons with it are born lacking C1 esterase inhibitor
Non-pitting edema

Question 10

What is autoimmunity?

Answer 10

persons are tolerized to self antigens which prevents autoimmune disease

Question 11

Deregulation of the immune response may be initiated by cross reactivity with what?

Answer 11

microbial antigens

ex: group A step or rheumatic factor

Question 12

Polyclonal activation of lymphocytes induced by what?

Answer 12

tumors or infection

Ex: malaria, epstein barr virus infection

Question 13

Autoimmune reactions result from the presence of what?

Answer 13

autoantibodies, activated T cells, and hypersensitivity reactions

Question 14

Individuals with certain MHC antigens are at a higher risk for what?

Answer 14

autoimmune responses
ex: human leukocyte antigen, juvenile RA, ankylosing spondylitis
responses are associated with inflammatory TH1 type responses

Question 15

Multiple sclerosis, an inflammatory response directed against myelin basic protein, may be triggers by what?

Answer 15

immune responses to one or more viruses, such as human herpesvirus 6 or measles

Question 16

Systemic Lupus Erythematosus (SLE) is a chronic inflammatory autoimmune disorder may affect what?

Answer 16

organ systems
skin
joints and
internal organs

Question 17

SLE may be mild or severe and life threatening, for most only a mild disease. What two categories of people are affected more then others?

Answer 17

African Americans and Asians

Question 18

90% of individuals have discoid rash rather then ?

Answer 18

generalized SLE

Question 19

Pediatric autoimmune neuropsychiatric disorders (PANDA) is associated with streptococcal infections. What are some examples of these disorders?

Answer 19

Describes children who have obessive compulsive disorder and/or tic disordres such as Tourette’s Syndrome
symptoms worsen following strep or scarlet fever

Question 20

What is the mechanism for PANDA?

Answer 20

It is thought to be similar to that of rheumatic fevers know as syndenhams chorea or st.vitus dance

Question 21

Immunosuppression therapy is important for reducing excessive inflammatory or immune responses of macrophages and T cells or for preventing the rejection of tissue transplants by T cells. Each card will go through the different immunosuppression treatments. 1. Anti-inflammatory treatments

Answer 21

Primarily target the production and action of TNF, IL-12 and IL-1

Question 22

2nd immunosuppression therapy is Corticosteriods

Answer 22

Prevents their production by macrophages and may be toxic to T cells. Soluble forms of the TNF receptor and antibody to TNF can be used to block the binding of TNF and prevent its action

Question 23

3rd is immunosuppression therapy for transplantation

Answer 23

generally inhibits the action or causes the lysis of T cells.

Question 24

4th immunosuppression therapy is cyclosporin

Answer 24

tacrolimus and rapamycin prevent the activation of T cells. Anti-CD3 and antiCD25 prevent action of T cells to prevent a response

Question 25

5th immnuosuppression therapy is antibody administation

Answer 25

to costimulatory molecules such as B7 or CD40 ligand at the time of transplant can block proper T-cell activation and promote anergy rather then responsiveness

Question 26

Exotoxins are what?

Answer 26

Proteins that can produced by gram positive or gram negative bacteria and include cytolytic enzymes and receptor-binding proteins that alter a function or kill the cell

Question 27

What are superantigens?

Answer 27

A special group of toxins that activate t cells by binding simultaneously to a t cell receptor and a major histocompatibility complex class II (MHCII) molecule on another cell without requiring antigen

Question 28

Nonspecific means of activating T cells can trigger life threatening what?

Answer 28

Autoimmune like responses by stimulating the release of large amounts of interleukins, such as IL-1 and IL2

Question 29

Superantigen stimulation of T cells can also lead to death of what?

Answer 29

the activated T cells causing the loss of specific T cell clones and their immune responses

Question 30

Superantigens include what?

Answer 30

• -toxic shock syndrome of S. aureus
• -staphylococcal enterotoxins
• -erythrogenic toxin A or C of S. pyogenes