Immunodeficiency Flashcards
What type of block is associated with low T and B cells?
Block type 1- Severe combined immunodeficiency Disease (SCID)
What type of block is associated with high IgM and low IgG and IgA
Block type 3- X-linked HyperIgM syndrome
What type of block is associated with absent T cells and normal B cells?
Block type 5- DiGeorge Syndrome
What type of block is associated with normal numbers of pre-B cells and B cells but the B cells have difficulty producing antibodies?
Block type 4- Common Variable Immundeficiency (CVID)
What type of block is associated with normal T cells but low to absent B cells?
Block type 2- X-linked Bruton’s Agammaglobinemia
What is the problem in block type 3?
Defect in CD40 ligand or in CD40 on B cells. This surface marker induces the switch.
B cell is made but no switch is made past IgM.
Thus too much IgM.
In which block type is there a defect in the stroma?
Block type 5- DiGeorge. Stroma develops abnormally and does not support lymphoid development in the thymus
What kind of genetic pattern is SCID?
X-linked recessive.
What kind of block involves a defect in the gene for the gamma chain that forms part of the receptors for IL2 and other cytokines necessary for lymphoid development?
Block 1 (SCID-X1)
B cell deficiency is characterized by infections with “high-grade” (pus-producing) bacterial pathogens such as _______
Staph. Aureus
Transient hypogammaglobulinemia children present with what type of infection?
gram positive bacterial infectionAlso this condition accounts for about 15% of chronic diarrhea
When would you want to use IVIG?
When B cell function is deficient.
It is usually about 99% IgG and must be administered monthly.
What might be a good treatment for SCID patients?
Bone marrow transplant or even better is purified stem cell transplant.
An assay for C1inh inhibitor might be used to test what?
The functioning of complement in a patient.
Describe the location of each of the 5 blocks in the lymphocyte development.
- Blocks development of Lymphoid Stem Cell
- Blocks Pre-B –> B cell
- Blocks IgM to IgG switching
- Blocks B-cell to Plasma Cell differentiation.
- Abnormal development of the 3rd and 4th pharyngeal pouch (thymic lymphoid development problems)
Describe the disorder of each of the 5 blocks in lymphocyte development.
- SCID (Severe combined immunodeficiency disease)
- X-linked (Bruton) Agammaglobinemia
- X-Linked HyperIgM Syndrome
- Common Variable Immunodeficiency (CVID)
- DiGeorge Syndrome
SeXXy Brunettes are Hyper ‘Cause Dang
What infections would you see in a pure B-cell deficiency?
“High grade” pyogenic (pus producing) infection from bacteria.
eg Staph Aureus
What infections would you see in a pure T-cell deficiency?
Severe infections from intracellular pathogens such as viruses, certain bacteria, yeasts and fungi.
eg candida
What are some of the clinical (physical) features found in DiGeorge Syndrome?
- Wide eyes (bug eyes)
- Down slanting eyes (Asian eyes)
- Fishmouth deformity
- Low set ears
How common is selective IgA deficiency? What other syndromes are associated with IgA def?
1 in 500.
Where is IgA found? In the GI tract.
What’s one of the most common GI problems today?
Celiac Disease
Nude mice (irradiated) may be used to model which human deficiency?
DiGeorge.
Irradiation kills T-cells.
SCID may be both X linked and Autosomal Recessive. Which one is associated with an enzyme deficiency. Which enzyme is missing?
How do you treat it?
- Autosomal Recessive SCID
- Adenosine Deaminase
- Enzyme Replacement or Irradiated RBCs because Adenosine Deaminase is prevalent in blood.
What transplants are associated with DiGeorge Syndrome?
Fetal Thymus or Thymic stromal cell transplant.
What tests could you run to determine that a patient has a B-Cell Deficiency?
- Serum Protein Electrophoresis
2. Antibody tests
What tests could you run to determine that a patient has a T-Cell Deficiency?
- Skin Test with recall Ag Panel
2. CD3, 4, 8 counts
