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88 Cards in this Set
- Front
- Back
What's found in the medulla of the thymus?
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Mature T cells
Epithelial reticular cells (that express self antigens) Hassall's corpuscles |
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Histo appearance of thymic cortex vs medulla?
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Cortex: dense
Medulla: pale |
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Rectum above pectinate line drains to what nodes?
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Internal iliac nodes
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Anal canal below pectinate line drains to what nodes?
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Superficial inguinal nodes
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Stimulus for development of helper T cell into either Th1 or Th2?
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IL-12 --> Th1
IL-4 --> Th2 |
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HLA DR 7 association?
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Steroid-responsive nephrotic syndrome
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HLA DR 5 associations?
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Pernicious anemia (B12 deficiency)
Hashimoto's thyroiditis |
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HLA DR 4 associations?
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Rheumatoid arthritis and DM type 1
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Graves' disease HLA association?
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HLA B8
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Hemochromatosis HLA association?
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HLA A3
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HLA DR2 associations?
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MS, hay fever, SLE, Goodpasture's
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Antigen loading location for MHC I?
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RER
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Antigen loading location for MHC II?
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Loaded following release of invariant chain in an acidified endosome
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Function of beta-2 microglobulin?
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Aids in transport of MHC I and antigen to cell surface
- can also form amyloid |
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Cytokines that enhance natural killer cell activity?
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IL-12, IFN-beta, IFN-alpha
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Macrophage-lymphocyte interaction?
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Activated lymphocytes release IFN-gamma
Activated macs release IL-1, TNF-alpha --> stimulate each other |
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Inhibition of Th1 and Th2 cells?
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Th1: inhibited by IL-10 from Th2 cells
Th2: inhibited by IFN-gamma from Th1 cells |
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Perforin vs granzyme?
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Granzyme: serine protease, activates apoptosis inside target cell
Perforin: helps deliver content of granules into target cell - both released from cytotoxic T cells |
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What is granulysin?
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Antimicrobial, induces apoptosis
- released from cytotoxic T cells |
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4 methods of generating Ab diversity?
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1. Random VJ/VDJ recombination
2. Random heavy + light chain combos 3. Somatic hypermutation 4. Addition of nucleotides during recombination (terminal deoxynucleotidyl transferase) |
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APC - CD4 interactions?
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MHC II - CD4 (with TCR)
B7 - CD28 (costimulation) |
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Th2 - B cell interaction?
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CD40L (Th cell) - CD40R (B cell)
Th2 releases IL 4, 5, 6, 10 |
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Virus infected cell, Th1, and CD8 T cell interaction?
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MHC I (virus infected) - CD8/TCR (CD8 T cell)
Costimulation: IL 2 (Th1) - IL 2 R (CD8) |
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T cell location in spleen?
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Periarterial lymphatic sheath (PALS) and white pulp
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B cell location in spleen?
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Follicles in white pulp of spleen
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Blood smear findings post-splenectomy?
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- Howell-Jolly bodies (nuclear remnants in RBCs)
- Target cells - Thrombocytosis |
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2 factors that are decreased with splenic dysfunction?
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1. Decreased IgM (--> decreased complement activation/opsonization of encapsulated organisms)
2. Decreased tuftsin (normally increases ability of macrophages to phagocytose) |
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Location of APCs in spleen?
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Marginal zone (outer edge)
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3 diseases that involve increased follicle size in lymph nodes?
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HIV, RA, SLE
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Medullary cords vs sinuses?
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Cords: closely packed lymphocytes and plasma cells
Sinuses: reticular cells and macrophages |
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Area of lymph node enlarged in extreme cellular immune response?
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Paracortex (houses T cells)
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What happens to thymus-independent antigens?
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Can't be presented to T cells by MHC (because they lack peptide component)
--> stimulate release of IgM Abs only and do NOT result in immunologic memory |
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What are thymus dependent antigens?
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Antigens that contain a protein component
--> Class switching and immunologic memory occur after B cell interaction with Th2 cells (CD40-40L and release of IL 4, 5, 6) |
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What are patients with IL-12 deficiency at risk for?
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Decreased Th1 response --> disseminated mycobacterial infections
- decreased IFN-gamma levels |
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Patients with chronic mucocutaneous candidiasis have deficient what?
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T cell dysfunction
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Features of Hyper-IgE syndrome (Job's syndrome)?
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"FATED":
coarse (leonine) Facies cold (non-inflamed) staph Abscesses retained primary Teeth IgE Derm problems (eczema) + red hair ^^ Due to failure of Th cells to produce IFN-gamma --> neutrophils can't respond to chemotactic stimuli |
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Defective CD40L on helper T cells causes what condition?
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Hyper IgM syndrome
- inability to class switch - severe pyogenic infections early in life |
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Sinus, lung infections, milk allergies, diarrhea, anaphylaxis when exposed to IgA, frequent SP/giardia infections. Disease?
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Selective Ig deficiency
- IgA deficiency most common --> failure to mature into plasma cells - decreased secretory IgA |
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Cause and risks of CVID?
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Caused by defect in B-cell maturation.
Increased risk of autoimmune disease (ITP, AIHA), lymphoma/malignancy, sinopulmonary infections, pneumonia, GI, etc |
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Lab findings in CVID?
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Normal number of B cells
Decreased plasma cells and immunoglobulin |
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Differentiation of Bruton's agammaglobulinemia vs CVID?
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CVID: normal # B cells
Bruton's: decreased number of B cells (normal pro-B) |
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Cause and presentation of Bruton's agammaglobulinemia?
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Cause: X-linked recessive defect in BTK (tyrosine kinase) --> blocks pre-B to mature B cell maturation
Present with recurrent bacterial infections after 6 months (decreased maternal IgG) due to opsonization defect |
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2 factors that prevent complement activation on self cells?
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Decay accelerating factor (DAF) and C1 esterase inhibitor
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Effect of C3a and C5a?
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Anaphylaxis
(C5a: also neutrophil chemotaxis) |
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Deficiency of C3 causes what?
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Severe, recurrent pyogenic sinus and respiratory tract infections
Increased susceptibility to type III hypersensitivity reactions |
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Complement factors involved in alternative pathway?
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C3, B, D
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Complement factors involved in classic pathway?
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C1, C2, C4, C3
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Passive immunity is available for how long and after what exposures?
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Half life of Abs ~ 3 weeks
After exposure to: Tetanus toxin, Botulinum toxin, HBV, Rabies |
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Bacteria with antigenic variation?
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Salmonella (flagella variants)
Borrelia (relapsing fever) Neisseria gonorrhoeae (pilus prot) |
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Bacterial superantigens link what to what?
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Cross-link beta region of TCR to MHC Class II on APCs
--> uncoordinated release of IFN-gamma from Th1 cells --> release of IL-1, IL-6, and TNF-alpha from macs |
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Molecular pathway of endotoxin/lipopolysaccharide?
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Directly stimulate macrophages by binding to endotoxin receptor CD14 (no Th cell involvement)
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Cell surface proteins on B cells?
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Ig, CD19, CD20, CD21, CD40, MHC II, B7
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Cell surface proteins on T cells?
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TCR, CD3, CD28
- CD4, CD40L - CD8 |
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Cell surface proteins on macrophages?
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MHC II, B7, CD40, CD14, receptors for Fc and C3b
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Cell surface proteins on NK cells?
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Receptors for MHC I, CD16 (binds Fc), CD56 (unique for NK cells)
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Alpha and beta vs gamma interferon?
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Alpha and beta: inhibit viral protein synthesis
Gamma: increase MHC I and II expression and antigen presentation in all cells |
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IL-12?
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Secreted by macrophages and B cells.
Induces differentiation of T cells into Th1 cells and activates NK cells. |
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Actions of TNF-alpha?
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Mediates septic shock. Activates endothelium. Causes leukocyte recruitment and vascular leak.
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Idiopathic thrombocytopenia purpura (ITP) hypersensitivity type?
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Type II hypersensitivity
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Polyarteritis nodosa hypersensitivity?
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Type III hypersensitivity
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Hypersensitivity pneumonitis type?
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Type III hypersensitivity
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Graft vs host hypersensitivity type?
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Type IV hypersensitivity
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Hashimoto's hypersensitivity type?
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Type IV hypersensitivity
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Guillain-Barre hypersensitivity type?
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Type IV hypersensitivity
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Type 1 DM hypersensitivity type?
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Type IV hypersensitivity
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Multiple sclerosis hypersensitivity type?
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Type IV hypersensitivity
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Ab in mixed connective tissue disease?
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Anti-U1 RNP (ribonucleoprotein)
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Anti-desmoglein Ab?
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Pemphigus vulgaris
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Abs in Hashimoto's?
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Antimicrosomal, Antithyroglobulin
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Ab in polymyositis, dermatomyositis?
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Anti-Jo-1
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IL-2 receptor antibody and use?
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Daclizumab
- used to prevent acute rejection of renal transplant |
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Rituximab mechanism and use?
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Anti-CD20
- B cell Hodgkin's lymphoma |
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Anti-CD3 antibody and use?
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Muromonab-CD3 (OKT3)
- prevent acute transplant rejection |
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Uses of alpha interferon?
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Hepatitis B, C
Kaposi's sarcoma Leukemias Malignant melanoma |
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2 drugs for treatment of thrombocytopenia?
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Oprelvekin (IL-11) and Thrombopoietin
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2 drugs for recovery of bone marrow?
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Filgrastim (G-CSF)
Sargramostim (GM-CSF) |
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IL-2 recombinant cytokine and use?
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Aldesleukin
- used for renal cell carcinoma and metastatic melanoma |
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Sirolimus (rapamycin) mechanism and AEs?
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Inhibit mTOR --> inhibit T cell proliferation in response to IL-2
AEs: hyperlipidemia, thrombocytopenia, leukopenia |
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Antimetabolite precursor of 6-mercaptopurine?
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Azathioprine
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What do cyclosporine and tacrolimus (FK506) each bind to?
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Cyclosporine: bind cyclophilins
Tacrolimus: bind FK-binding protein Both inhibit release of IL-2 and cytokines |
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Toxicity of cyclosporine?
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Predispose patients to viral infections and lymphoma
- nephrotoxic (preventable with mannitol diuresis) - hirsutism |
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Toxicity of tacrolimus?
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Nephrotoxicity
Peripheral neuropathy HTN Pleural effusion Hyperglycemia Hair loss |
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Role of IL-10?
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Modulate inflammatory response. Inhibit actions of activated T cells and Th1. Activate Th2.
Secreted by Th2 cells and regulatory T cells. |
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Cause of and findings in Leukocyte adhesion deficiency (type 1)?
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Defect in LFA-1 integrin (CD18) protein on phagocytes
Get recurrent bacterial infections, absent pus formation, delayed separation of umbilicus. |
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Recurrent pyogenic infections (staph, strep), partial albinism, peripheral neuropathy. Disease?
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Chediak-Higashi syndrome.
Defect in microtubular function with decreased phagocytosis. |
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Thrombocytopenic purpura, Infections, Eczema. Disease and cause?
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Wiskott-Aldrich syndrome.
Progressive deletion of B and T cells. X linked recessive defect. |
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Triad in ataxia-telangiectasia?
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Cerebellar defects (ataxia)
Spider angiomas (telangiectasias) IgA deficiency |
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Lab values in Wiskott-Aldrich syndrome?
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High IgE, IgA
Low IgM Normal IgG Progressive deletion of B and T cells. X linked recessive defect. |