Immunology Flashcards
How does antigen loading for MHC II work?
Antigen loaded following release of invariant chain in acidified endosome
How does antigen loading work for MHC I?
Antigen peptides loaded onto MHC 1 in RER after delivery via TAP peptide transporter
What diseases associated with DR2?
Multiple sclerosis, Goodpasture, hay fever, SLE
What diseased associated with DR3?
SLE, DM type 1, Grave’s
What is allotype?
Minor changes in constant region of antibodies that are different in each person. Hence, IgG in one person will be different from another. Used for paternity testing
What is isotype?
The class of antibody: IgG vs IgM vs IgA etc.
What is idiotype?
What epitope/antigen the antibody binds
What happens when IgE is released due to presence of helminths, parasites?
Causes killing by ADCC
What happens when IgE is released because of hypersensitivity?
Causes mast cells (mostly) and basophil degranualation
What is primarily responsible for killing gram negative bacteria?
MAC because gram - bacteria doesn’t have good peptides for presentation by MHC
What does IL-5 do?
Promote differentiation of B cells, enhance IgA class switching, stimulate differentiation/growth of eosinophils
What do interferon alpha and beta do?
They prime locally uninfected cells so that when virus invades, it activates RNAase L (degradation of mRNA) and protein kinase (inhibition of protein synthesis) resulting in apoptosis.
What is arthus reaction?
Intradermal injection of antigen causes antibodies to form resulting in ag-ab complexe in skin. Causes edema, necrosis, activation of complement.
What is the diagnosis if you see a child with hepatic abscess without cause?
CGD
What drug does allopurinol increase the toxicity of?
Azathioprine (metabolized by xanthine oxidase)
What does natalizumab increase the risk for?
PML
What is the treatment for MS?
IFN-beta and Natalizumab
What is Alemtuzumab?
CD52 antibody for CLL
What is tryptase specific for?
Mast cells
What else can you have if you have reactive arthritis?
Sacroilitis because of the HLA-B27 assocation
What is the problem in Hyper IgM?
CD40L mutation (AR) so can’t class switch. Get severe pyogenic infections early in life.
What is XLA (bruton)?
No antibodies so susceptible to bacteria and enteroviral infections after 6 months. Don’t see germinal centers
How to macrophages repsond to LPS?
Activate TNF
Where is complement made?
Liver
C3 deficiency makes you susceptible to what?
Encapsulate bacteria
What is IL-8 for?
Neutrophil chemotaxis particularly for pus formation
What does IL-3 do?
GM-CSF stimulation
Which are antiinflammatory?
TGFbeta and IL10
What is for diapedesis?
PECAM
What is messed up in SCID?
XR: defective IL-2R gamma chain
AR: adenosine deaminase deficiency
What needs to happen for MHC II to present?
Need to fuse with acidified phagolysosomes with antigen
Pregnant women should get what vaccine?
Tetanus so they can transfer protective antibodies to child
Why is pus and sputum green?
MPO production
What do you get cerebellar atrophy, ataxia, spider angiomas, sinopulmonary infections with?
Ataxia-telangiectasia; also increases risk for cancer
Do eosinophils do protozoa?
NO
What causes septic shock?
TNF-alpha
What can drug infusion cause?
Serum sickness leading to hypocomplementemia
What does LTB4 do?
Neutrophil chemotaxis
What is prostacyclin?
PGI2 (inhibits platelet aggregation)
What mediates cachexia?
TNF-alpha (aka cachectin; mainly), IFN-gamma, IL-6
What is it if you see lymphadenopathy, facial edema, diffuse skin rash after 2-8 weeks taking sulfa drugs?
DRESS: usually with anticonvulsants, allopurinol, sulfa drugs, and antibiotics. Also get eosinophila
What do you see on CBC with DRESS?
Eosiniophilia
What type of hypersensitivity is acute hemolytic transfusion?
Type II: complement mediated
What disease do you see DNA hypersensitivity to ionizing radiation?
Ataxia- Telangiectasia due to DNA double strand breaks
What does chronic rejection of heart look like?
Atherosclerosis
What does chronic rejection of lung look like?
Bronchiolitis obliterans
What does chronic rejection of liver look like?
Vanishing bile ducts
What does chronic rejection of kidney look like?
Vascular fibrosis, glomerulopathy
Diagnosis: maculopapular rash, jaundice, diarrhea, hepatosplenomegaly post transplant?
GVHD
Where do the dorsolateral foot and posterior calf drain?
Popliteal LN
What causes edema in patient with fluctuant lesion from scrape on tree branch?
Separation of endothelial junction (allows migration of cells)
