Chapter 11 ( Primary Immunodeficiencies )

Question 1

The 3 integrins that contain CD18 ?

Answer 1

LFA-1
MAC-1
gp150/95

Question 2

Chediak-Higashi syndrome molecular defects ? Symptoms ?

Answer 2

Nonsense mutation in the lysosomal trafficking regulator CHS1/LYST protein leads to aberrant fusion of vesicles

Symptoms :
Recurrent infection with bacteria 
Chemotactic and degranulation defects 
Absent NK activity 
Partial albinism

Question 3

Hyperimmunoglobulin E syndrome ( Job syndrome ) defect ? Symptoms ?

Answer 3

Defect in JAK-STAT signaling pathway leading to impaired Th17 function : decreased INF-gamma production

Symptoms : 
Characteristic facies 
Severe recurrent sinopulmonary infections
Pathologic bone fractures 
Retention of primary teeth 
Increased IgE 
Eczematous rash

Question 4

Bruton agammaglobulinemia defect ? Symptoms ?

Answer 4

Deficiency of the Bruton tyrosine kinase which promotes B cell expansion

Symptoms :
Increased susceptibility to encapsulated bacteria and bloodborne viruses
Low immunoglobulins of all isotypes
Absence or low level of circulating B cells

Question 5

Defect of X linked hyper IgM syndrome ?

Answer 5

Deficiency of CD40L on activated T cells

Question 6

Elevation of which immunoglobulin is seen in selective IgA deficiency ?

Answer 6

IgE

Question 7

Transient hypogammaglobulinemia of infancy defect ? Symptoms ?

Answer 7

Delayed onset pf normal IgG synthesis

Detected in month 5-6 of life , resolves months 16-30 , susceptibility to pyogenic bacteria

Question 8

Deficiency of complement regulatory proteins example ? Signs ?

Answer 8

C1-INH deficiency ( hereditary angioedema )

Overuse of C1 , C4 , C2
Edema of mucosal surfaces

Question 9

Classic pathways deficiencies ? Signs ?

Answer 9

C1q , r , s
C4
C2

Marked increase in immune complex diseases
Increased infections with pyogenic bacteria

Question 10

MHC l deficiency defect ? Symptoms ?

Answer 10

Failure of TAP 1 molecules to transport peptides to endoplasmic reticulum

CD8+ T cell deficient
Recurring viral infections

Question 11

Wiskott-Aldrich syndrome defect ? Symptoms ?

Answer 11

Defect in the WAS protein which plays a critical role in actin cytoskeleton rearrangement

Immunodeficiency ( maybe elevated IgA and IgE )
Eczema
Thrombocytopenia

Question 12

Ataxia telangiectasia defect ? Symptoms ?

Answer 12

Defect in the ATM kinase involved in the detection of DNA damage and progression through the cell cycle

Ataxia
Telangiectasia
Deficiency of IgA and IgE

Question 13

SCID defects ? Symptoms ?

Answer 13

1- X-linked defects in common gamma chain of IL-2 receptors
Chronic diarrhea , skin , mouth and throat lesions and opportunistic infections , low levels of circulating lymphocytes , cells unresponsive to mitogens

2- adenosine deaminase deficiency
Clinical overlap with X-linked SCID plus neurologic deficiency

3- rag1 or rag2 gene nonsense mutations
Total absence of B and T cells