MI 06a: Immunodeficiencies

Question 1

Primary (acquired/congenital) immunodeficiencies differ from (acquired/congenital) immunodeficiencies in that they’re caused by (X).

Answer 1

Congenital;
Acquired
X = mutations in genes

Question 2

Congenital immunodeficiencies typically exhibit which mode of inheritance?

Answer 2

Autosomal or X-linked recessive

Question 3

Why would patients with congenital immunodeficiencies be susceptible to cancers?

Answer 3

Susceptible to infection by oncogenic viruses

Question 4

Patient with congenital immunodeficiency will likely present with which general symptoms?

Answer 4

Repeated and recurrent infections

Question 5

Congenital immunodeficiencies can result from defects in lymphocyte (maturation/activation) or from defects in effector mechanisms of (innate/adaptive) immunity.

Answer 5

Any of those!

Question 6

For many congenital immunodeficiencies, (X) can result in a cure.

Answer 6

X = bone marrow transplant

Question 7

T/F: Many congenital immunodeficiencies are fatal if not treated.

Answer 7

True

Question 8

T/F: Child with congenital immunodeficiency will manifest disease in first few days of life.

Answer 8

False

Question 9

For the first (X) period of time after birth, children have immunity to fight infection from maternal (Y).

Answer 9

X = 6 months
Y = IgG

Question 10

Briefly describe histopathology you’d see in B cell deficiency.

Answer 10

Absent/reduced follicles and germinal centers in lymphoid organs

Question 11

Briefly describe lab test abnormalities you’d see in B cell deficiency.

Answer 11

Reduced serum Ig levels

Question 12

Briefly describe histopathology you’d see in T cell deficiency.

Answer 12

Reduced T cell zones in lymphoid organs

Question 13

Briefly describe common infectious consequences you’d see in B cell deficiency.

Answer 13

Pyogenic (pus-inducing) and enteric bacterial infections

Question 14

Briefly describe common infectious consequences you’d see in T cell deficiency.

Answer 14

Viral (and other intracellular) microbial infections/malignancies

Question 15

In (X) immunodeficiencies, the histopathology and common infectious consequences can be quite variable (bacterial and viral).

Answer 15

X = innate

Question 16

In pyogenic bacterial infection, (X) are essential to clear the infection because (Y).

Answer 16

X = Ab and complement
Y = polysaccharide capsule makes bacteria resistant to phagocytosis

Question 17

SCID, aka (X), is a(n) (congenital/acquired) immunodeficiency that’s a result of defective (Y).

Answer 17

X = Severe Combined Immunodeficiency
Congenital;
Y = lymphocyte (B and T cell) maturation

Question 18

X-linked SCID: The mutation is in the gene encoding (X), required for (Y).

Answer 18

X = cytokine receptor common gamma chain
Y = signal transduction

Question 19

Mutation in gene encoding common (X) chain of cytokine receptor leads to (Y) disease. Which cytokine is affected?

Answer 19

X = gamma
Y = X-linked SCID

A panel of them (IL2, 4, 7, 13, 15, 21)

Question 20

X-linked SCID: defective T cell maturation is result of (high/low) (X) signals, which is especially necessary for (Y).

Answer 20

Low;
X = IL-7
Y = expansion/survival of early T cell progenitors in thymus

Question 21

It’s primarily (X) cells that are deficient in X-linked SCID. Why, then, is (cell-mediated/humoral) immunity affected?

Answer 21

X = T and NK
Humoral;
No T cell help (CD4)

Question 22

X-linked SCID: The lack of (X) indicates that the patient is especially deficient in which Ig subtype(s)?

Answer 22

X = CD4 T cell (help)

IgG, IgA, IgE

Question 23

X-linked SCID: defective NK cell maturation is result of (high/low) (X) signals.

Answer 23

Low;

X = IL-15

Question 24

Autosomal SCID: the real functional deficiency is (X), which is a result of (Y).

Answer 24

X = progressive loss of T and B cells
Y = toxic metabolite accumulation in lymphocytes

Question 25

T/F: In autosomal SCID, B and T cells are affected to an equal extent.

Answer 25

False - B cells to a lesser extent

Question 26

Autosomal SCID: mutation in genes that code (X), which is/are involved in (Y).

Answer 26

``` X = ADA and PNP enzymes Y = purine metabolism ```

Question 27

The first ever gene therapy trials were in a patient with (X) mutations, aka (Y) disease.

Answer 27

``` X = ADA Y = autosomal SCID ```

Question 28

The most common syndrome linked to B cell deficiency is (X), with decrease in which serum Ig isotypes?

Answer 28

X = XLA (X-linked agammaglobulinemia) ALL

Question 29

The molecular cause of XLA is mutation in gene encoding (X), which is required by (Y) to (Z).

Answer 29

``` X = Btk (tyrosine kinase) Y = Pre-BCR Z = signal and allow IgL rearrangement/progression of B cell development ```

Question 30

In XLA, (T/B)-cell development is suspended at which stage?

Answer 30

Pre-B cell

Question 31

T/F: XLA can be cured with modern medicine.

Answer 31

False

Question 32

Common treatment for XLA involves providing (active/passive) immunity via (X).

Answer 32

Passive; | IVIg (human IgG) every 3-4 weeks for life

Question 33

Bare lymphocyte syndrome is a deficiency in (X), thus also a deficiency in (Y).

Answer 33

``` X = MHC Class II expression Y = CD4 T cells ```

Question 34

Bare lymphocyte syndrome: the mutation is in genes encoding (X), which are necessary for (Y).

Answer 34

``` X = transcription factors Y = MHC class II expression ```

Question 35

Bare lymphocyte syndrome: there's a lack of (X) expression on which cells?

Answer 35

X = MHC Class II APCs and thymic epithelial cells

Question 36

T/F: Bare lymphocyte syndrome involves general deficiency in T cells.

Answer 36

False - only CD4 (not CD8)

Question 37

Bare lymphocyte syndrome: which specific process is affected?

Answer 37

Positive selection for CD4 T cells

Question 38

Hyper IgM syndrome: (increase/decrease) lymphocytes and (increase/decrease) of which Ig isotypes?

Answer 38

Normal numbers of lymphocytes; high serum IgM, low serum IgG, IgA, IgE

Question 39

Hyper IgM syndrome: most common mutation is in gene encoding (X). What's the mode of inheritance?

Answer 39

X = CD40L (on T cell) X-linked

Question 40

Hyper IgM syndrome: less common mutation is in gene encoding (X). What's the mode of inheritance?

Answer 40

X = CD40R Autosomal recessive

Question 41

Disease involving mutations in IL-12 and IFN-gamma receptor genes. Which specific cell type/process would you expect to find defect in?

Answer 41

Th1 (differentiation)

Question 42

Disease involving mutations in IL-17 ligand and receptor genes. Which specific cell type/process would you expect to find defect in?

Answer 42

Th17 (differentiation)

Question 43

Chronic granulomatous disease (CGD) is (congenital/acquired), affecting (innate/adaptive) immune system. What's the specific functional deficiency?

Answer 43

Congenital; innate Inability of macrophages/neutrophils to efficiently kill phagocytosed microbes

Question 44

Chronic granulomatous disease (CGD): mutation in gene encoding (X), which is necessary for (Y).

Answer 44

``` X = phagocyte oxidase Y = production of ROS ```

Question 45

Leukocyte Adhesion Deficiency (LAD) is (congenital/acquired), affecting (innate/adaptive) immune system. What's the specific functional deficiency?

Answer 45

Congenital; Innate and adaptive Inability of neutrophils/macrophages and T cells to traffic to site of infection

Question 46

In Leukocyte Adhesion Deficiency (LAD), a CBC would show abnormally (high/low) (X).

Answer 46

High; | X = WBC

Question 47

In Leukocyte Adhesion Deficiency (LAD), LAD-1 mutation is in gene encoding (X).

Answer 47

X = CD18 (beta-2 integrin common chain of leukocytes)

Question 48

In Leukocyte Adhesion Deficiency (LAD), LAD-2 mutation is in gene encoding (X).

Answer 48

X = E and P selectin ligands

Question 49

Mutations in C3 gene, leading to deficiency, makes patient especially susceptible to (X) infections due to defect in (Y).

Answer 49

``` X = pylogenic bacterial Y = opsonization (marking microbe for phagocytosis) ```

Question 50

T/F: Certain therapy treatments can cause acquired immunodeficiencies.

Answer 50

True - chemo and irradiation

Question 51

T/F: Removal of spleen can cause acquired immunodeficiency.

Answer 51

True

Question 52

List the modes of transmission of AIDS.

Answer 52

1. Sexual intercourse 2. Needles 3. Blood transfusion

Question 53

HIV is primarily targeting (X) cells, but also targets (Y) cells.

Answer 53

``` X = CD4 T Y = macrophages and dendritic cells ```

Question 54

Which surface ligand(s) help HIV bind (X) cell's (Y) receptor(s)?

Answer 54

``` X = CD4 T Y = CD4 and chemokine (CCR5) ``` gp120/gp41 ligand

Question 55

Aside from its (X) number of (DNA/RNA) copies, HIV carries which key enzymes?

Answer 55

X = 2 RNA; 1. Reverse transcriptase 2. Integrase 3. Protease

Question 56

HIV is a typical (X) virus, with outer envelope made from (Y).

Answer 56

``` X = retro- Y = protein ```

Question 57

(X) cell(s) are likely initial hosts for HIV. And in the first, (Y), phase of infection, these cells transport virus to (Z).

Answer 57

``` X = dendritic Y = acute Z = lymph tissue (node) ```

Question 58

During HIV infection, there's a period of clinical latency (with little to no manifestations). What's going on in this period?

Answer 58

Slow destruction of CD4 T cells

Question 59

The course of HIV disease is measured by amount of (X) in (Y).

Answer 59

``` X = HIV and CD4 T cells Y = blood ```

Question 60

A(n) (X) cell count that's (greater/less) than (Y) is indicative of AIDS.

Answer 60

X = T Less than Y = 200 cells/mm3

Question 61

Lack of thymic shadow on chest x-ray is indicative of which (congenital/acquired) immunodeficiency?

Answer 61

Congenital; | X-linked SCID

Question 62

Anti-(X) Ab are used to screen for HIV.

Answer 62

X = envelope and p24

Question 63

T/F: Multiple types of MHC Class I molecules can be expressed on a given cell.

Answer 63

True

Question 64

T/F: Each MHC Class I molecule binds to its own specific cognate antigen protein.

Answer 64

False

Question 65

T/F: T cells can recognize antigen bound to either self or non-self MHC.

Answer 65

False

Question 66

T/F: MHC Class I has the primary role of recognition of self-peptides.

Answer 66

True