Immunology Flashcards
What are the causes of Severe Combined Immunodeficiency (SCID)?
Mutations in genes encoding gamma chain of IL-2, 4, 7, 9, 15, 21
What are the symptoms of SCID?
Chronic diarrhea, thrush, recurrent infections
-B cells may be normal, impaired Ts
An allergic rxn that occurs 48-72hrs after exposure is what kind of hypersensitivity rxn?
Type IV: T-cell mediated destruction of tissue via macros
Multinucleated giant cells in leprosy possess which CD designation?
CD14
What do Th1 cells secrete?
IFN-gamma, IL-2
What do Th2 cells secrete?
IL-4, 5, 13
Autoinfection from ascaris lumbricoides leads to what immunological rxn?
IgE and eosinophilia (type I hypersensitivity)
What is the most important immunological tool against orgs with capsule as their major virulence factor?
IgG-mediated opsonization and/or C3b
Recurrent Neisserial infections are indicative of what deficiency?
Deficiency of complement factor C6, C7, or C8 (the ones that make MAC)
Which cells would be most numerous in granulomas?
macros
Which cytokine would show increased conc in Multiple Sclerosis?
Interferon-gamma
What causes chronic graft rejection?
T-cells sensitized against the graft (immunosuppressive agents directed towards T-cells)
What are the immunological symptoms of DiGeorge Syndrome?
decreased T-cells = absent type IV hypersensitivity; recurrent viral/fungal infections
What is leukocyte adhesion deficiency?
Defect in LFA-1 integrin (CD18) = impairs migration and chemotaxis
- no pus formation
- delayed separation of umbilical cord
Which cell would be address malaria in the erythrocytic stage?
NK cells bc RBCs dont have MHC
Which tests are used to detect anti-Rh antibodies in mother and fetus?
Indirect Coombs: IgG anti-Rh in mother’s serum
Direct Coombs: IgG antibodies bound to fetal RBCs
What are the antibodies and effector cells in: Type I hypersensitivity?
IgE; basophils and mast cells
What are the antibodies and effector cells in: Type II hypersensitivity (cytotoxic)?
Always autoimmune (=complement)! IgG/IgM; leukos/macros/NKs
What are the antibodies and effector cells in: Type II hypersensitivity (non-cyto)?
IgG; None
What are the antibodies and effector cells in: Type III hypersensitivity?
IgG/IgM; leukos/macros
+ complement
What are the antibodies and effector cells in: Type IV hypersensitivity?
None; CTL/Th1/macros
Which hypersensitivity rxn causes rheumatic fever?
Type II (autoimmune abs against strep)
What is chronic granulomatous disease?
Def in NADPH oxidase = susceptibility to catalase (+) orgs [staph, candida, aspergillus
What deficiency leads to decreased removal of immune complexes?
C3 def = defect in opsonization –> decreased removal of ICs
Which immuno cell is needed for s. pneumo infection?
neutrophil
In which disease do you find p-ANCA?
Churg-Strauss: vasculitis, asthma, eosinophilia
Churg-Strauss = PAVE
What is Goodpasture Syndrome?
Type II (autoimmune) hypersensitivity = abs against collagen type IV in glomerular/lung basement membrane
What is the histological manifestation of Goodpasture Syndrome?
Direct fluorescence of abs shows linear pattern of IgG deposition in gloms
What type of hypersensitivity is the rxn to poison ivy?
Type IV: Th1 –> IFN-gamma –> macros
What is hemolytic disease of the newborn?
Maternal anti-Rh IgG abs and causes hemolytic anemia in fetus
What type of hypersensitivity is hemolytic disease of the newborn?
Type II (cytotoxic) = auotimmune
What do cytotoxic T cells require to eliminate tumor cells?
MHC class I molecules on the tumor surface
Which immuno process is needed to remove immune complexes?
Classical complement pathway –> C3b
Which complement factor chemoattracts neutros?
C5a
What is Hyper-IgM syndrome?
Deficiency due to inability to isotype switch bc Th2 cells lack CD40L = lots IgM, no others
Which cell surface marker indicates macros?
CD14
Graves disease is considered what type of hypersensitivity?
Type II (non-cytotoxic) bc abs are against TSH receptors, not tissues
What are the 2 most important chemotactic factors for neutros?
C5a and IL-8
What is Eaton-Lambert Syndrome (like MS)?
Abs against the presynaptic Ca channels at the NMJ, leading to inhibition of Ach release
- proximal muscles especially of the lower limbs
What are the hallmarks of Antiphospholipid antibody syndrome?
Often w SLE; History of hypercoagulability and miscarriage + prolonged PTT
Which immuno cell gets rid of mycobacteria?
neutros
What is the function of myeloperoxidase?
convert hydrogen peroxide into hyalide radicals
What protein is assoc w Ankylosing spondylitis?
HLA-B27 (MHC I)
What is Chédiak-Higashi disease?
defect in LYST: Microtubule dysfunction in phagosome-lysosome fusion = Recurrent staph/streptococci infections,
partial albinism*
-neutropenia, giant granules in neutros
What happens with aspirin-induced-asthma?
aspirin triggers the attack by inhibiting the production of prostaglandins = arachidonic acid converted to leukotrienes by the enzyme lipooxygenase –> bronchoconstriction
What causes chronic graft rejection?
arteriolosclerosis of the engrafted organ
What is chronic granulomatous disease? Its 2 biggest hallmarks?
NADPH oxidase deficiency
- susceptible to oxidase + orgs (s. aureus, e.coli, listeria, etc)
- Nitroblue tetrazolium dye reduction test is ⊝
Your pt has recurrent bacterial and viral infections and has albinistic features, what disease do you suspect?
Chediak-Higashi
What is the drug of choice for pregnant pts with RMSF?
chloramphenicol (only concern is grey baby syndrome near term)
Which factors mediate neutrophil chemotaxis?
"Clean up on isle (IL) 8 B4 5 A.m." Il-8 Leukotriene-B4 C5a formyl-methionyl peptides
