Distinguishing

Question 1

How would you distinguish ADA from other B cell deficiencies?

Answer 1

Effects B cells, T cells, NK cells

classified as a combined immunodeficiency

Question 2

How would you distinguish BTK deficiency from a BLNK deficiency clinically? How are they different?

Answer 2

X-link agammaglobulinemia:
clinically identical to other one
BTK is an x-linked disorder: female siblings won’t have it.
BTK oversees heavy chain Ig switching

low/absent G A M

agammaglobulinemia:
clinically identical to other one
can effect both boys/girl siblings
BLNK is the linker b cell protein that regulates downstream signaling, the Ig-a and Ig-m, and light chain lamda chains are all effected

low/absent G A M

Question 3

agammaglobulinemia is ______ genetic disorder, while the other is

Answer 3

autosomal recessive

x-linked

Question 4

how can Common Variable immune deficiency be distinguished from agammaglobulinemia diseases?

Answer 4

they would exhibit immature B cell BCRs, but can’t developing into plasma generators. in which case IgM can be normal or low.

normal/low IgM, NO IgG or IgA

another distinguishing marker would be late acquirement

Question 5

agammaglobulinemia vs common variable immune deficiency:

recurrent bacterial infections

Answer 5

CVID

problems with IgG and IgA

Question 6

mutations in CD40L—->

Answer 6

Hyper IgM syndrome

x-linked: Men only.

hyperproduction of IgM,
but low IgA and IgG

effects somatic recombination and Ig class switching

CD40L triggers B cell differentiation, responsible for 2/3 cases of HIGM

autosomal CD40 deficiency (both sexes) accounts for 1/3/ of cases of HIGM

Question 7

Low memory B lymphocytes, but normal peripheral B lymphocytes

Answer 7

hyper IgM syndrome

Question 8

Age range for CVID vs HIGM vs Agamma’s

Answer 8

CVID –> 2 years, or 20s or 30s, usual age around 4-5 yrs
HIGM: no information
Agammas: 5-6 months

Question 9

Normal IgG, IgA, IgG, IgM

Answer 9

Isolated IgG subclass deficiency

Question 10

A child is brought into your office and has low IgG2, what illness is this?

Answer 10

common in children, may not be an illness

Question 11

a patient apparently has very low IgG4, what illness is this

Answer 11

common for most people to have low or no IgG4, not an illness

Question 12

Isolated IgG illnesses are often seen in

Answer 12

lung infections, respiratory tract infections