Immunology - Immunodeficiencies

Question 1

Immunodeficiency that is mostly inborn (genetic) and often detected in infancy or childhood (sometimes adulthood)

Answer 1

Primary Immunodeficiency

Question 2

Immunodeficiency that is acquired due to external factors

Answer 2

Secondary Immunodeficiency

Question 3

Causes the inability of Pro-B cells to differentiate into Pre-B cells

Answer 3

X-linked agammaglobulinemia

Question 4

In XLA, they can make a ______ chain variable region but not a ______ chain, so they are unable to make antibodies

Answer 4

heavy; light

Question 5

Enzyme lacking in XLA

Answer 5

Tyr kinase

Question 6

Clinical features of XLA

Answer 6

• Usually only affects males (X-linked)
• Recurrent respiratory infections call attention to the disease

Question 7

T/F: Most bacteria causing recurring respiratory infections in patients with XLA are gram (+)

Answer 7

True

Question 8

Diagnostic findings for XLA (3)

Answer 8

• B-cell absence or very decreased
• All immunoglobulins are depressed
• B-cell areas of lymphatic tissues are underdeveloped

Question 9

XLA treatment

Answer 9

IVIG therapy

Question 10

Immunological issues present with common variable immunodeficiency (3)

Answer 10

• defects in most classes of Ab secretion
• inability of Th cells to amplify Ab production
• reduced CT cell activity

Question 11

A common feature of CVI is __________, usually involving all AB classes but sometimes only IgG

Answer 11

hypogammaglobulinemia

Question 12

Clinical features of CVI

Answer 12

Resembles XLA - recurrent infections; also can have recurrent severe herpes infection

Question 13

Diagnostic findings of CVI

Answer 13

• no other B-cell abnormality
• reduced immunoglobulins
• B-cell areas of lymphatic tissues are hyperplastic

Question 14

Treatment of CVI

Answer 14

IVIG therapy

Question 15

Most common primary immune deficiency

Answer 15

Isolated IgA deficiency - 1/600

Question 16

Symptoms of patients with Isolated IgA deficiency?

Answer 16

Most asymptomatic

Question 17

Patients with Isolated IgA deficiency have a Hx of recurrent…?

Answer 17

otitis media, sinusitis, bronchitis, pneumonia, GIT infections

Question 18

Potentially deadly complication of Isolated IgA deficiency?

Answer 18

Anaphylaxis post-blood transfusion since transfused IgA antibodies recognized as foreign

Question 19

Clinical pearl of IgA deficiency?

Answer 19

Serology for detecting celiac disease is based on IgA detection => IgA deficiency can lead to false negatives in celiac patients

Question 20

Immunodeficiency where patients make IgM but have difficulty producing IgG, IgA, IgE?

Answer 20

Hyper-IgM Syndrome

Question 21

What chromosome is Hyper-IgM Syndrome gene on?

Answer 21

X chromosome

Question 22

In Hyper-IgM Syndrome, Th-cells can’t activate ______ and _______

Answer 22

B-cells and macrophages

Question 23

Clinical features of hyper-IgM syndrome

Answer 23

• Recurrent purulent infection (CNS, resp tract, GIT)
• Many viral infections
• decreased neutrophil counts

Question 24

Treatment for hyper-IgM syndrome?

Answer 24

IVIG and intense antibiotic prophylaxis

Question 25

T-cell deficiency in which the 3rd and 4th pharyngeal pouches don't develop

Answer 25

22q11 deletion (DiGeorge) Syndrome

Question 26

With DiGeorges syndrome, you're short on...?

Answer 26

A thymus parathyroid gland, some thyroid tissue - also heart and great vessel defects

Question 27

Hypothesized that the _____ family of transcription factors is absent/doesn't function, which is important for the transcription of _________.

Answer 27

T-box; brachial/pharyngeal arch development and large vessels

Question 28

Because of thymic hypoplasia resulting in variable loss of T-cells, what is increased?

Answer 28

Increased fungal and viral infections, and autoimmunity

Question 29

Clinical features of DiGeorge syndrome

Answer 29

- Cardiac abnormalities - Craniofacial abnormalities - Developmental delay - Hypoparathyroidism

Question 30

What electrolyte abnormality is associated with hypoparathyroidism?

Answer 30

Ca and P

Question 31

Blood products can result in what for patients with DiGeorge syndrome?

Answer 31

graft-vs-host disease

Question 32

What is graft-vs-host disease?

Answer 32

Mothers T-cells are transferred across the placenta occasionally, causing the mom's lymphocytes to attack the baby's tissue

Question 33

A multitude of etiologies defined by recurrent, severe infections by a wide range of pathogens

Answer 33

Severe Combined Immunodeficiency

Question 34

What is required in SCID patients to ensure death doesn't occur at a young age?

Answer 34

Bone marrow transplant or stem cell therapies

Question 35

In SCID, there are defects in both ______ and ______ immunity.

Answer 35

cell-mediated and humoral

Question 36

What is X-linked SCID due to?

Answer 36

mutation in the gamma-chain of a variety of cytokine receptors

Question 37

Signal transducing component of what receptors for which IL's are affected?

Answer 37

IL-2, IL-4, IL-7, IL-9, IL-11, IL-15, IL-21

Question 38

What is autosomal SCID due to?

Answer 38

mutation in adenosine deaminase and RAG mutations

Question 39

What does adenosine deaminase mutation do?

Answer 39

causes accumulation of deoxyadenosine and its derivatives = toxic to rapidly dividing lymphocytes

Question 40

What does a RAG mutation do?

Answer 40

Blocks B-cell and T-cell development

Question 41

Pathological findings of SCID?

Answer 41

- small thymus with few lymphocytes - depletion in T-cell areas of other lymphatic tissue

Question 42

Most common complement defect?

Answer 42

C2 deficiency

Question 43

Why do many people with C2 deficiency have no increased incidence of infection?

Answer 43

Alternative pathway is adequate for most cases

Question 44

Autosomal dominant disorder less common than the complement deficiency disorders, that causes a deficit in C1 inhibitor?

Answer 44

Hereditary angioedema

Question 45

Results of a deficit in C1 inhibitor?

Answer 45

- unchecked activation of classical pathway - Increased bradykinin production - increased activation of certain components of clotting cascade

Question 46

Clinical features of hereditary angioedema

Answer 46

- episodic attacks that usually progressively become worse - severe abdominal pain - swelling of face, hands, legs, groin

Question 47

Hereditary angioedema treatment

Answer 47

C1 inhibitor from blood products

Question 48

Fungal infection of the lung

Answer 48

Pneumocytis jiroveci pneumonia

Question 49

Reactivation of varicella zoster virus => painful rash

Answer 49

Herpes Zoster (shingles)

Question 50

Conversion of latent TB to active form that usually affects the lungs

Answer 50

Tuberculosis

Question 51

A chronic parasitic infection usually acquired through direct contact with contaminated soil

Answer 51

Stringyloidiasis