Immunology - Deficiency In Adaptive Immunity

Question 1

What is SCID? (Severe combined immunodeficiency disease)

Answer 1

low numbers of B AND T cells. No conversion of SCH to SLL.

Presents as lymphopenia of B and T cells, absent thymic shadow, small tonsils and low serum immunoglobulins.

Question 2

SCID-XI

Answer 2

X-linked (about 50%)

defect in famma chain that forms part of receptor for IL-2.

Question 3

ADA

Answer 3

Autosomal Recessive

lack enzyme adenosine deaminase. Adenosine accumulates in cells, which is particularly damaging to lymphocytes.

Question 4

V(D)J defect

Answer 4

common in Navajo children. Issues with recombination.

Question 5

Three forms of SCID

Answer 5

SCID-XI
ADA
V(D)J defect

Question 6

What is Brutons?

Answer 6

X-linked disease

Absence of B cells (normal T-cells) b/c lack of protein tyrosine kinase gene btk in pre-B cells which is required to mature to B-cells

Question 7

People with Bruton’s are susceptible to…

Answer 7

Bacterial infections: pneumonia, chronic diarrhea
Enterovirus: enter via mucous membrane, protected from via IgA. One of the reasons we don’t give oral polio vaccine anymore.

Question 8

X-linked IgM Syndrome

Answer 8

Lol its x linked

defect of IgM to IgG-IgA switching mechanism.

defective CD40 ligand on Tfh cell OR B-cell. Conversion will not happen if either is dysfunctional.

Question 9

Transient Hypogammaglobulinemia of Infancy

Answer 9

self-limiting condition - all that happens is kids are slow to get their production of IgG going

Characterized by: reoccurring Gram+ infections.

May be the cause of 15% of infant chronic diarrhea

Question 10

Selective IgA Deficiency

Answer 10

Seen in people w/ diarrhea and sinopulmonary infection, increased frequency/severity to allergies

Much more frequent in people w/ Celiacs disease

Question 11

Ataxia Telangiectasia

Answer 11

wtf are these names

Autosomal Recessive

Characterized by sinus infections, pneumonia, ataxia (staggering) and talengiectasia (dilated abnormal blood vessels)

both B and T cell deficiency, but PARTICULARLY IgA deficiency

Defect in DNA repair - high incidence of tumors

Question 12

Wiskott-Aldrich Syndrome

Answer 12

X-linked disease

platelet and B-cell deficinecy, eczema, reoccurred bacterial infections

Question 13

Secondary Immunodeficiency

Answer 13

Can be caused by drugs like corticosteroids and monoclonal antibodies

Viral illnesses - measles, mononucleosis, and cytomegalovirus infection

of course, AIDS

Question 14

What is CVID? (Common Variable Immunodeficiency?)

Answer 14

When B-cells are difficult to trigger.

IgG is very low.

Recurrent bacterial infections.

Treated with IVIG or SCID.

Question 15

What is DiGeorge Syndrome?

Answer 15

caused by large deletion on Ch. 22.

absent T-cells, normal B-cells.

No parathyroids, convulsions from calcium deficiency.

Tetralogy of Fallot

Characterized by viral and fungal infections

(similar to nude mice!)

Question 16

What is the significance of lack of development of pharyngeal pouches 3 +4?

Answer 16

The stroma of the thymus come from the endoderm and ectoderm from these pouches.

AND the parathyroid glands.

And some great vessels of the heart.

And facial symmetry.

Question 17

You dont have to know this but just for fun - what the heckie is Tetralogy of Fallot?

Answer 17

1. ) Pulmonary infundibular Stenosis (narrowing of R ventricular outflow tract at or below pulmonary valve)
2. ) Overriding aorta - aortic valve connecting to both the R and L ventricle.
3. ) Ventricular septal defect - hole between two ventricles
4. ) Right ventricular hypertrophy - self-explanatory

Question 18

Treatments used in ADA

Answer 18

irradiated red cell transfusions are great! Because RBC’s are filled with adenosine deaminase and irradiation helps get rid of residual leukocytes

purified ADA w/ polyethylyne glycol is available for IV infusion

gene replacement therapy has been tried… inserted via lentivirus! looks promising.

Question 19

Treatments for DiGeorge

Answer 19

Fetal thymus graft, stromal cells may reduce risk of graft v host disease

Question 20

Treatments for SCID

Answer 20

Bone marrow transplant has about 50% success rate. Graft v host disease a huge problem, best from siblings w/ perfect MHC II match

gene replacement therapy also done… looks promising!

Question 21

Treatment for B-cell deficiencies

Answer 21

Human immunoglobulin administered via IV or subcutanously (SCIG)

monthly infusion, 99% IgG

Question 22

Why did the boy in the bubble die after receiving a bone marrow transplant fro his sister? (he probs had SCID)

Not a learning objective just cool

Answer 22

most healthy marrows contain latent virus such as cytomegalovirus and Epstein-Barr Virus.

These are innocuous in healthy individuals, but may kill someone completely immunocompromised like the bubble boy.