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20 Cards in this Set
- Front
- Back
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what is the only cure for SCID?
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bone marrow transplant
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what are the four subsets of SCID?
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X-linked
ADA deficient PNP deficient RAG gene deficient |
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what should you be cautious about when vaccinating a child with SCID?
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Vaccination w/ any live vaccine may lead to the child developing the disease and dying
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what is the main defect in X-linked SCID?
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IL-7 receptor defective leading to halted T cell maturation
d/t the defective gamma chain of IL-2 which is the same gamma chain of Il-4, 7, 9, 11 and 15. The defective chain of IL-2 --> defective IL-7 receptor --> defective IL-7 |
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what is IL-7?
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its an interleukin that is the terminal receptor for T cell maturation
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A mother brings her 6 month in complaining of recurrent infections since birth. She mentions that her Father and grandfather had the same things happen to them as a child. On physical exam you notice that the child has an angry red diaper rash. What do you need to give this patient as a prophylaxis?
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PCP tx - TMP-SX
This child has X-linked SCID and because he has absolutely no T cells he will need to get a Bone marrow transplant for a curative option. Otherwise, tx will be IV gammaglobulin + antimicrobial. |
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what induces the 3 signaling pathways that TCR causes after antigen recognition? what are those 3 signaling pathways?
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ZAP70
Induction of NFAT (nuclear factor of activated T cells), NFkB, AP-1. These will induce the proliferation and differentiation genes of activated T cells (including cytokines (IL-2 and IFN-gamma)) |
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what are the three mitogens? what type of cells are they specific for?
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PHA- Tcells
CON A- T cells PWM- T and B cells |
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where is positive selection of the T cells done? negative selection?
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Positive- cortex- binds all who recognize
negative- medulla- kills off those who bind too tightly |
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what are the 3 types of SCID under autosomal SCID? what is their mode of inheritance?
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1) Adenosine deaminase deficiency
2) Purine nucleoside phosphorylase deficiency 3) RAG gene deficiency all are AR |
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A mother brings in her 3 month old boy and complains about recurrent infections. On physical exam you notice dusky muscoa and you decide to do a CXR and notice a ground glass appearance of the lung fields. You also noticed a small thymus for his age. If you drew blood, what would you expect? ddx? tx
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on CBC: expect a decrease in lymphocytes because of the deficiency of ADA (if it is ADA) would have a relative deficiency in 5'nucleotidase (compensatory enzyme) which is only in lymphocytes.
ddx: ADA (accumulation of dATP) and PNP (accumulation of guanosine metabolites) tx: commercially available ADA and PNP, definitive: BMT distinguish w/ an enzyme test |
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what are you determining when you measure proliferation of T cell by incorporating 3H-Thymidine when you are preparing for a BMT?
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Determining the difference in MHC class II alleles. The more proliferation the worse the prognosis bc these cells will create problems after transplant d/t alloreactivity.
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how do you determine the differences in MHC class I when you are preparing for BMT?
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measure the killing of 51 Cr labeled target cells to detect activated cytotoxic T cells.
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what is the RAG gene essential for? what does a deficiency in this gene end up leading to?
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RAG gene is essential for VDJ recombination in T and B cell gene. A deficiency leads to an inability of cleavage and repair of DNA during somatic recombination of T and B cell receptor. This ultimately results in a failure in T and B cells.
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A mother brings her 7 month old girl to your office complaining of diarrhea and this generalized red rash that has been on her body for as long as mom could remember. On physical exam you palpate the tip of the spleen and some axilla and inguinal LN. You also noticed that she is in the 10% of her growth curve for her age. Dx and tx
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Omenn Syndrome
d/t missense mutation of RAG tx: IV gammaglobulin + antibiotics BMT |
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what are the two type of recombination signal sequences? How many spaces are between the defined sequences? how about the non-defined sequences?
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Heptamer (7bp) and nonamer (9bp)
defined: heptamer is separated by a 12 bp spacer and then the nonamer undefined: heptamer and nonamer are separated by 23 bp |
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who's cells are irradiated in a BMT? what is left behind?
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Donor's; The large cells are left behind like APC and dendritic cells. This will allow only the recipient's cells to proliferate bc they are the only ones w/ lymphocytes.
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what do the recombination signal sequences provide? What is the main Cell type associated with this?
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recognition sites for VDJ recombinase which will cut and rejoin DNA (RAG-1 and 2).
Only lymphocytes have RAG-1 and 2 (RAG- recombination activating genes) |
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on what chromsome are the alpha and beta chain of TCR on?
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alpha- chromosome 14 (homologous to light chain)
beta- chromosome 7 (homologous to heavy chain) |
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what is the test that is done to check for histocompatibility?
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MIxed lymphocyte reaction (MLR)
Good match- minimal proliferation |
