Immunodeficiency I

Front 1

What are primary immunodeficiencies?

Back 1

1. Inherited disorders of one or more components of the immune system

Front 2

What are secondary immunodeficiencies?

Back 2

1. Result from extrinsic causes

Front 3

What leads to recurrent/chronic pyogenic infections?

Back 3

1. Defect in antibodies, B cells, complement, or phagocytes

2. Caused by encapsulated bacteria

3. Sinusitis, OM, bacterial pneumonia, meningitis

Front 4

What leads to opportunistic infections or cancer?

Back 4

1. Defect in T cells

2. Caused by viruses, fungi, or parasites

Front 5

When does passive protection from maternal antibodies end?

Back 5

1. 3-6 mos.

Front 6

How do you tx primary B cell/antibody deficiencies?

Back 6

1. Ig replacement tx

2. IVIG

3. SCIG

Front 7

What are the ssx of XLA?

Back 7

1. Males only

2. Pyogenic bacterial infections don't respond to abx

3. Giardiasis and GI viruses

4. Bronchiectasis

Front 8

What is the molecular defect that leads to XLA?

Back 8

1. BTK gene defect---- prevents B cell maturation at early stage

Front 9

How do you dx XLA?

Back 9

1. Scant lymphoid tissue

2. Near absence of all antibody classes

3. Near absence of CD19 B cells

4. BTK gene defect

Front 10

How do you tx XLA?

Back 10

1. Antimicrobials

2. Replacement Ig

Front 11

What are the ssx of selective IgA deficiency?

Back 11

1. Recurrent OM, sinusitis, bronchitis, pneumonia

2. GI infections, chronic diarrhea

3. Asthma, SLE, RA

Front 12

What is the role of IgE in selective IgA deficiency?

Back 12

1. Can possess IgE towards IgA

Front 13

How do you dx selective IgA deficiency?

Back 13

1. Serum IgA <5-7 mg/dL

2. Normal IgG and IgM

Front 14

How do you tx selective IgA deficiency?

Back 14

1. Antimicrobials

2. AVOID IVIG and SCIG

Front 15

What are the ssx of IgM and IgG2 deficiencies?

Back 15

1. Can't respond to polysaccharide capsules on bugs or in vaccines

2. Repeated infections by encapsulated bacteria, especially S. pneumoniae

Front 16

What is unique to an IgG2 deficiency as compared to an IgM deficiency?

Back 16

1. Asthma

Front 17

How do you dx IgM and IgG2 deficiencies?

Back 17

1. Measure serum IgA, IgM, and IgG

2. If total IgG is normal but suspicion remains, check IgG subclasses

3. Measure pre- and post-vaccination titers to pneumococcus

Front 18

How do you tx IgM and IgG2 deficiencies?

Back 18

1. Abx for infections

2. Replacement IgG +/-

Front 19

What are the ssx of transient hypogammaglobulinemia of infancy?

Back 19

1. Physiologic hypogammaglobulinemia at 6 mos.

2. Mom's IgG has decayed, baby's hasn't caught up

3. OM, URT, LRT infections, asthma, eczema

Front 20

What is the molecular defect in transient hypogammaglobulinemia of infancy?

Back 20

1. B or T presenting as Ab deficiency

Front 21

How do you dx transient hypogammaglobulinemia of infancy?

Back 21

1. Serum IgG low

2. IgM and IgA normal or low

Front 22

How do you separate transient hypogammaglobulinemia of infancy from XLA?

Back 22

1. Circulating B cells express CD19, CD20, and IgM

Front 23

How do you tx transient hypogammaglobulinemia of infancy?

Back 23

1. Antimicrobials as needed

2. Killed vaccines ok

Front 24

What is the presentation of CVID?

Back 24

1. Pyogenic bacterial infections

2. Swollen spleen and lymph nodes

3. Granulomas

4. Giardiasis

Front 25

What usually precedes CVID?

Back 25

1. EBV infection--- CD21

2. IgA deficiency

Front 26

What is the maternal consequence of CVID?

Back 26

1. Mothers cannot confer passive immunity on infants

Front 27

What is the molecular defect in CVID?

Back 27

1. B cells do not develop into plasma cells--- low serum Abs

2. Sporadic or familial defects in B or T cells

Front 28

How do you dx CVID?

Back 28

1. Serum IgG always low (IgA often, IgM sometimes)

2. CD27 low

3. Low antibody response to vacines

Front 29

How do you tx CVID?

Back 29

1. Abx

2. Ig replacement

Front 30

What is the presentation of hyper-IgM syndrome?

Back 30

1. Recurrent respiratory infections beginning at 1-2 years

2. X-linked--- autoimmunity, malignancies, viral, bacterial, fungal, and parasitic infections

Front 31

What is the molecular defect in hyper-IgM syndrome?

Back 31

1. No class-switching from IgM to other isotypes

2. X-linked--- CD40L on T cells

3. Autosomal--- B cell defects

Front 32

How do you dx hyper-IgM syndrome?

Back 32

1. Reduced IgG

2. Reduced IgA

3. IgM elevated or normal

Front 33

How do you tx hyper-IgM syndrome?

Back 33

1. Abx

2. Replacement Ig

3. Stem cell transplant for XHIGM

Front 34

What is the presentation of SCID?

Back 34

1. Susceptible for all types of infections

2. Diarrhea and pneumonia

3. Vaccination with live microbes is lethal

4. Fatal before 1 if not treated

Front 35

How do you tx SCID?

Back 35

1. Antimirobials

2. Stem cell transplant

Front 36

What are the 4 phenotypes of SCID?

Back 36

1. T-B+

2. T-B-

3. T+B-

4. T+B+

Front 37

What T cell count points to SCID?

Back 37

1. <2000

Front 38

What is the defect in x-linked SCID?

Back 38

1. Absent y chain for IL-2, Il-4, IL-7, IL-9, and IL-15 absent

2. NK cells absent

Front 39

What is the defect in JAK 3autosomal recessive SCID?

Back 39

1. No signal transduction from y chain of IL receptors because JAK3 is missing

2. NK cells absent

Front 40

What is the defect in IL-7R autosomal recessive SCID?

Back 40

1. a chain of IL-7 receptor is absent

2. NK cells normal

Front 41

What is the MC subtype of SCID?

Back 41

1. X-linked

Front 42

What is the molecular defect in ADA deficiency?

Back 42

1. Adenosine deaminase purine salvage deficiency

2. Buildup of dATP in cells

Front 43

How do you tx ADA deficiency SCID?

Back 43

1. ADA supplementation

2. HLA-matched stem cell transplant

Front 44

What is the molecular defect in recombinase deficiencies with radio sensitivity?

Back 44

1. Mutations in RAG-1 and RAG-2

2. Prevents maturation of lymphocytes at pre-T and pre-B stages

3. No T, B, or antibodies

Front 45

How do you tx recombinase deficiencies with radio sensitivity?

Back 45

1. Stem cell transplant

Front 46

What are some secondary health problems that ADA-SCID patients have to worry about?

Back 46

1. Hypothyroidism

2. DM

3. Anti-ADA Ab

4. Thrombocytopenia

5. Hemolytic anemia

Front 47

What is Omenn syndrome?

Back 47

1. "Leaky" SCID with partial RAG activity

2. Massive skin infiltration by eosinophils and TH2 cells secreting IL-4 and IL-5

3. No circulating B cells

4. Hyper IgE

Front 48

What is bare lymphocyte syndrome?

Back 48

1. Cells lack MHC I, II, or both

2. No collaboration between APCs and T cells

Front 49

What is deficient in class I bare lymphocyte syndrome?

Back 49

1. TAP molecules

2. No loading of processed peptide into class I HLA groove

3. Class I HLA becomes unstable, not expressed on cell surface

Front 50

What type of bare lymphocyte syndrome presents with symptoms?

Back 50

1. Class II