Immunology - Deficiency In Adaptive Immunity Flashcards
What is SCID? (Severe combined immunodeficiency disease)
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.
SCID-XI
X-linked (about 50%)
defect in famma chain that forms part of receptor for IL-2.
ADA
Autosomal Recessive
lack enzyme adenosine deaminase. Adenosine accumulates in cells, which is particularly damaging to lymphocytes.
V(D)J defect
common in Navajo children. Issues with recombination.
Three forms of SCID
SCID-XI
ADA
V(D)J defect
What is Brutons?
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
People with Bruton’s are susceptible to…
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.
X-linked IgM Syndrome
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.
Transient Hypogammaglobulinemia of Infancy
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
Selective IgA Deficiency
Seen in people w/ diarrhea and sinopulmonary infection, increased frequency/severity to allergies
Much more frequent in people w/ Celiacs disease
Ataxia Telangiectasia
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
Wiskott-Aldrich Syndrome
X-linked disease
platelet and B-cell deficinecy, eczema, reoccurred bacterial infections
Secondary Immunodeficiency
Can be caused by drugs like corticosteroids and monoclonal antibodies
Viral illnesses - measles, mononucleosis, and cytomegalovirus infection
of course, AIDS
What is CVID? (Common Variable Immunodeficiency?)
When B-cells are difficult to trigger.
IgG is very low.
Recurrent bacterial infections.
Treated with IVIG or SCID.
What is DiGeorge Syndrome?
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!)
What is the significance of lack of development of pharyngeal pouches 3 +4?
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.
You dont have to know this but just for fun - what the heckie is Tetralogy of Fallot?
- ) Pulmonary infundibular Stenosis (narrowing of R ventricular outflow tract at or below pulmonary valve)
- ) Overriding aorta - aortic valve connecting to both the R and L ventricle.
- ) Ventricular septal defect - hole between two ventricles
- ) Right ventricular hypertrophy - self-explanatory
Treatments used in ADA
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.
Treatments for DiGeorge
Fetal thymus graft, stromal cells may reduce risk of graft v host disease
Treatments for SCID
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!
Treatment for B-cell deficiencies
Human immunoglobulin administered via IV or subcutanously (SCIG)
monthly infusion, 99% IgG
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
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.
