Immunodeficiencies

Question 1

X-linked (Bruton) Aggamaglobulinemia

Answer 1

B cell disorder
Defect in BTK (tyrosine kinase gene)–>no B cell maturation
X-linked Recessive
Presents: recurrent bacterial and enteroviral infections after 6mo old

Question 2

Selective IgA deficiency

Answer 2

B cell disorder
Unknown defect, most common primary immunodeficiency
Presents: A's
Usually Asx
can see Airway and GI infections
Autoimmune dz
Atopy
Anaphylaxis to IgA-containing products

Question 3

Common Variable immunodeficiency

Answer 3

B cell disorder
Defect in B-cell differentation
Present: can be acquired
Increased risk of autoimmune dz, bronchiectasis, lymphoma, sinopulmonary infections

Question 4

Thymic aplasia (DiGeorge Syndrome)

Answer 4

T cell disorder
22q11 deletion, failure of 3rd and 4th pharyngeal pouches (absent thymus and parathyroids)
Present: tetany, recurrent viral/fungal infections, conotruncal abnormalities

Question 5

IL-12 receptor deficiency

Answer 5

T cell disorder; autosomal recessive
Decreased Th1 response
Dissemininated mycobacterial and fungal infections; may present after BCG vaccine

Question 6

Hyper-IgE Syndrome (Job Syndrome)

Answer 6

T cell disorder, autosomal dominant
Deficiency of Th17 cells d/t STAT3 Mx-->impaired recruitment of neutrophils to sites of infection
Presents: FATED
coarse Facies
cold (noninflamed) staphylococcal Abscesses
retained primary Teeth
increased IgE
Dermatologic problems (eczema)

Question 7

Chronic Mucocutaneous Candidiasis

Answer 7

T cell dysfunction, multiple causes
Noninvasive Candida albicans infections of skin and mucous membranes
Absent in vitro T cell proliferation in response to candida

Question 8

Severe Combined Immunodeficiency

Answer 8

B and T cell disorder
Multiple types: defective IL-2R gamma chain is most common and X-linked vs the adenosine deaminase deficiency which is autosomal recessive
Presents: FTT, chronic diarrhea, thrush
recurrent bacterial, fungal and protozoal infections
Tx: bone marrow transplant

Question 9

Ataxia telangiectasia

Answer 9

B and T cell disorder
Defects in ATM gene-> failure to repair DNA double strand breaks-->cell cycle arrest
Presents as Triad:
cerebellar defects (Ataxia)
spider Angiomas (telangiectasia)
IgA deficiency

Question 10

Hyper- IgM syndrome

Answer 10

B and T cell disorder
commonly d/t defective CD40L on Th cells
X linked recessive
Severe pyogenic infections early in life, opportunistic infection with pneumocystis, cryptosporidium, CMV

Question 11

Wiskott-Aldrich Syndrome

Answer 11

B and T cell disorder
Mutation in WAS gene (T cells unable to reorganize actin cytoskeleton)
X-linked recessive
Presents: WATER
Wiskott Aldrich Syndrome
Thrombocytopenia
Eczema
Recurrent infections

Question 12

Leukocyte adhesion deficiency (type 1)

Answer 12

Phagocyte dysfunction
Defect in LFA-1 integrin (CD18)–> impaired migration and chemotaxis
autosomal recessive
Presents: recurrent bacterial skin and mucosal infections, absent pus formation, impaired wound healing, delayed separation of umbilical cord

Question 13

Chediak Higashi Syndrome

Answer 13

Phagocyte dysfunction
Defect in lysosomal trafficking regulator gene (LYST)
autosomal recessive
Recurrent pyogenic infection by staphylococci and streptococci, partial albinism, peripheral neuropathy, progressive neurodegeneration, infiltrative lymphohistiocytosis

Question 14

Chronic Granulomatous dz

Answer 14

Phagocyte dysfunction
Defect of NADPH oxidase
X-linked recessive is most common form
Increased susceptibility to catalase positive organisms