Acquired Immune Deficiencies

Question 1

Contrast secondary/ acquired immunodeficiency with primary deficiency.

Answer 1

secondly is due to insufficiency of a supporting component or an external factor decreased immune function

Question 2

Describe the ways in which DM leads to immunodeficiency.

Answer 2

diabetes can impair the function of cells involved in cellular and/or humoral immunity but the dysfunction of NEUTROPHILS is the most prominent (hyperglycemia makes PMNs dysfunction)

type 1 diabetics exhibit more immune dysregulation (autoimmune disease to begin with), co-existing vascular disease also contributes to infection (both neuropathy and cardiovascular compromise)

Question 3

What diseases/infections are diabetics more susceptible to?

Answer 3

respiratory infections such as pneumonia and influenza
skins and soft tissue infections
infections with candida
mucormycosis infection (rhino pulmonary zygomycosis)
malignant otitis external due to P. aeurginosa

Question 4

Describe why pregnant women are relatively immunocompromised.

Answer 4

“immune modulation”
pregnant women must be tolerant of foreign antibodies or risk rejecting the developing baby which puts them at increased susceptibility and severity of some infections

mechanisms of modulation include: progesterone (inhibits lymphocytic proliferation), uromodulin (inhibits B cell activity) and depressed T-cell responses

Question 5

List some infections that pregnant women are more susceptible to.

Answer 5

Hepatitis A, B, E
listeria
campylobacter
TB
Malaria
influenza
herpesvirus
chlamydia/GC

Question 6

How does protein/calorie malnutrition cause immunodeficiency?

Answer 6

protein-calorie malnutrition is associated with impaired cellular and humoral immunity (globally infections are the primary cause of morbidity and mortality in malnourished)

(via global metabolic disturbances, low levels of leptin, def. in nutrients)

Question 7

Describe the immune deficiency that develops with aging.

Answer 7

decrease of immune function with aging “immune senescence” includes decrease in size and function of the thymus, decreased in suppressor cell function and increase in auto-reacitivity

changes in lymphocyte development lead to reemergence of latent infections

Question 8

How do trauma and critical illness cause depressed reaction of the immune system?

Answer 8

trauma and critical illness can cause massive release of inflammatory cytokines
burns are associated with massive protein loss as wellas disruption of physical barriers to infection

Question 9

How does stress reduce immune function?

Answer 9

reduced natural killer cell activity
depressed lymphocyte mitogen responses
release of endogenous glucocoricoids

Question 10

V. vulnificus is ___ times more likely to spread into the bloodstream in people with compromised immune systems, especially those with _______ _____ ____.

Answer 10

80x more likely, especially those with chronic liver disease

Question 11

What GI conditions can lead lead to immunosuppression?

Answer 11

cirrhosis
end stage liver disease
protein losing conditions (IBD and celiac disease)

Question 12

What are the mechanisms of immune suppression in liver disease?

Answer 12

shunting of portal blood reduces Kupffer cells ability to clear opsonized organisms
cirrhotic patients often have very low compliment level
reduced hepatic metabolism of endogenous glucocorticoids

Question 13

What infections are common with ESLD?

Answer 13

sepsis, bacterial peritonitis (associated with ascites)
cryptococcal infection
candidate infection
infection with vibrio vulnificus

Question 14

Which diseases are associated with hypogammaglobulinemia through loss of large amounts of serum proteins?

Answer 14

nephrotic syndrome
IBD and celiac disease
massive lymphedema
peritoneal dialysis
burns
dermatitis

Question 15

B cell or T cell deficiencies have been noted in which hematological conditions?

Answer 15

multiple myeloma
Waldenstrom’s macroglobulinemia
Chronic lymphocytic leukemia
well differentiated lymphomas

hodgkin’s disease
advanced tumors

Question 16

Blood transfusion from a major-histocompatibility- unrelated donor has been clearly demonstrated to cause what?

Answer 16

immune suppressive with a greater risk of post-operative infections and cancer recurrence or metastasis, although the effect is NOT seen with leukocyte depleted blood

Question 17

List viral infections that modulate the immune system and list how the modulate.

Answer 17

measles: T-cell lymphopenia, cutaneous anergy, diminished T cell proliferation and diminished antibody production

HTLV: can produce aggressive T cell malignant neoplasm and severe immune defects and multiple opportunistic infections

herpesviruses ie. CMV: CMV in transplant patients places them at risk for other opportunistic infections such as PJP, aspergillosis and organ rejection

Question 18

How do super antigens modulate the immune system?

Answer 18

infections associated with toxin producing staph and strep can bind simultaneously to MHC class II antigens and to non-antigen-binding region of T-cell receptor

this stimulates T cells which produce inflammatory cytokines leading to septic shock- like situation

after hyper activation T cell become anergic and can longer be activated

Question 19

What are the effects of mycobacterial infection on the immune response?

Answer 19

they inhibit the ability of the infected cell to kill the invader and also prevent coordination of the immune response

this can lead to secondary infection and negative ppd despite active TB

Question 20

How do parasites repress the immune system?

Answer 20

production of immunosuppressive factors, suppression of macrophage function and induction of suppressor T cells

Question 21

Auto-immune conditions can lead to immune _________ as well as enhances ________.

Answer 21

autoimmune conditions lead to immune dysregulation and enhance the susceptibility of infection

e.g.: RA, SLE and granlomatosis polyangitis

Question 22

Describes ways in which renal dysfunction can be immune suppressive.

Answer 22

uremia
ESRD
nephrotic syndrome: protein loss
dialysis leads to reduced T cell functor, diminished antibody production (poor vaccine response), deficient PMN function)

Question 23

People on TNF inhibitors are at particular risk for what type of infection?

Answer 23

granulomatous infection including myobacterial infection and fungal infections