Diseases in the Immuncompromised

Question 1

what is the most common form of SCID

Answer 1

X-linked

Question 2

what defect causes X-linked SCID

Answer 2

defect in the gamma chain of the cytokine receptor or Jak3 gene

Question 3

a lack of which IL prevent T cell development

Answer 3

IL-7

Question 4

which cytokines usually bind the receptor which is defected

Answer 4

IL-2 IL-4 IL-7 IL-9 IL-15 IL-21

Question 5

which activity is affected in X linked SCID

Answer 5

cytokine responses

Question 6

what activities are affected in the various forms of SCID

Answer 6

t cell development, lymphocyte survival, vdj rcombination, tcr signalling

Question 7

what defect causes digeorge syndrome

Answer 7

deletion of chromosome 22

Question 8

what are the symptoms of digeorge syndrome

Answer 8

heart defects, cleft palette, autism, other learning difficulties

Question 9

which actvity is affected in digeorge syndrome

Answer 9

thymic development

Question 10

how does a lack of thymus in Digeorge syndrome cause prblems

Answer 10

there are no mature T cells

Question 11

how do SCID and CID differ

Answer 11

in CID there is still some residual function

Question 12

how is there a decrease in antibodies in Digeorge syndrome

Answer 12

a lack of T cells means a lack of b cell activation from t cell dependant antigens

Question 13

what is the treatment for digeorge syndrome

Answer 13

thymic transplant

Question 14

what type of immunodeficiency is bruntons aggamaglobulineamia

Answer 14

humoural immunodeficiency

Question 15

what process is affected in bruntons aggaaglobulinaemia

Answer 15

maturation of b cells

Question 16

what causes the lack of b cells in bruntons aggamaglobulinaemia

Answer 16

lack of Btk in the bone marrow

Question 17

is bruntons aggamaglobulinaemia x linked

Answer 17

yes

Question 18

how is bruntons agammaglobulinaemia treated

Answer 18

Ig therapy

Question 19

what sort of infections are patients with b cell defects likely to get

Answer 19

Pyogenic bacteria infections, viral infections and infections with strep. pneumonaie

Question 20

how do pyogenic bacteria infect patients with B cell defects

Answer 20

they have polysacccharride capsules which are not recognised by macrophages and neutrophils

Question 21

how are pyogenic bacteria usually cleared

Answer 21

complement and antibodies

Question 22

why are people with b cell defects susceptible to viral infections

Answer 22

because antibodies are important in neutralising viruses in the gut

Question 23

what virulence factors does streptococcous pneumonaie acquire when it becomes pathogenic when the host is immunocompromised

Answer 23

invasins, adhesins and immunogenic cell wall components

Question 24

what sort of immunodeficiency is leaves a patient susceptible to neisseria meningitis

Answer 24

complement deficiency

Question 25

what specific defect is linked to susceptibility to infection with niesseria meningitis and why

Answer 25

defects in the membrane attack complx as this allows intracellular survival as the host cant perform extracellular lysis

Question 26

what are the two types of innate immunodeficiency

Answer 26

defects in inflamatory response and defects in phagocyte killing

Question 27

what is process is effected in chronic granulomatus disease (CGD)

Answer 27

phagocyte killing

Question 28

what is the defect in CGD

Answer 28

NADPH oxidase

Question 29

what sort of disease is CGD

Answer 29

innate immunity

Question 30

how does the defect in CGD result in a compromised immune system

Answer 30

it causes difficulty in forming reactive oxygen species which impares bacterial killing

Question 31

what are the results of chronic granulomatus disease

Answer 31

recurrant infections incl pneumonia, absesses of the skin, septic arthritis, fungal infection and impetigo

Question 32

what are secondary immunodeficencies which can cause problems with the innate immune system

Answer 32

burns, trauma, surgery, smoking,CF, implanted devices, prolonged antibiotic therapy

Question 33

under what circumstances is a person susceptible to infection from staph. aureus and staph. epidermis

Answer 33

when the person has defective physical barrier or clearance mechanism

Question 34

what are the results of infection with staph aureus

Answer 34

boils or staphylococcal scalded skin syndrome in children

Question 35

what sort of bacteria is Staph. epidermidis

Answer 35

gram positive, catalase positive, coagulase negative cocci.

Question 36

which antibiotics is staph epidermidis resistant to

Answer 36

vancomycin penicillin and methicillus

Question 37

what is used to treat staph epidermis

Answer 37

novabiocin

Question 38

how does staph epidermis form biofilms

Answer 38

it produces an extracellular slime which can adhere to plastic surfaces via van der waals and anchor using adhesion molecules such as pili

Question 39

what are common infections in patients suffering from cystic fibrosis

Answer 39

s. aureus, haemophilus influenzae, pseudomonas aeruginosa and B. capecea

Question 40

what do the bacteria which commonly infect CF patients have in common

Answer 40

they are resistant to common antibiotics

Question 41

what 3 things causesreduced circulating neutrophils

Answer 41

radiotherapy, chemotherapy, leukeimia

Question 42

what are the most common infections in patients with phagocyte defects

Answer 42

S. aureus, S. pyogenes, Gram negative rods and P. aeruginosa

Question 43

which bacteria are patients with T cell defects likely to be infected by

Answer 43

mycobacterium avium and toxoplasma gondii

Question 44

is infection rate of mycobacterium avium inversely related to CD4+ counts or CD8+ counts

Answer 44

CD4+

Question 45

what is toxoplasma gondii

Answer 45

an intracellular protazoa

Question 46

what percentage of adults does toxoplasma gondii latently infect

Answer 46

35%

Question 47

what does the reactivation of latent toxoplasma gondii lead to in T cell deficient patients

Answer 47

toxoplasmic encephalitis

Question 48

how does infection from toxoplasma gondii usually occur

Answer 48

ingesting oocytes from unwashed veg or tissue cysts in undercooked meat