7 Immunology

q123456's version from 2016-06-01 18:54


Question Answer
antihistamine 1st generationhydroxyzine, promethazine, chlorpheniramine (nonselective, not for emergency) and diphenhydramine
pramine:tricyclic antidepressants

antimuscarinic(blurry vision, dry mouth and uringary retention),
anti-alpha adrenergic (hypotension and dizziness),
anti-serotonergic (appetide stimulation)
antihistamine 2rd generationfexofenadine no sedation and no antimuscarinic effects


Question Answer
type II non cytotoxic2 types of type 2 reactions:
non cytotoxic ( NO COMPLEMENT IgG mediated, no cells involved )
cytotoxic (COMPLEMENT INVOLVED, IgG,IgM mediated. cells are PMN, NK, Macrophages).

Myasthenia Gravis
Grave's disease
Pernicious anemia
Diabetes Mellitus (type II)
type II cytotoxicrheumatic disease=type II
rheumatoid arthritis and poststreptococcal glomerulonephritis=type III

rheumatic fever
bullous pemphigoid
pemphigus vulgaris
type IIIrheumatoid arthritis
poststreptococcal glomerulonephritis
serum sickness
arthus reaction
type IVMultiple sclerosis
type I DM
Guillain barre
graft versus host
Contact dermatitis (poison ivy) KA34/8


Question Answer
SLEAnti ANA, dsDNA, Smith
drug induced lupusAnti histone
rheumatoid arthritisAnti IgG (rheumatoid factor)
scleroderma CRESTAnti-centromere
scleroderma diffuseAnti-Scl-70 (anti-DNA topoisomerase I)
Primary biliary cirrhosisanti-mitochondrial
Celiacanti-gliadin, anti-endomysial
goodpastureanti basement membrane
pemphigus vulgarisanti-desmoglein
Hashimotoanti microsomal
Polymyositisanti JO-1
Sjogrenanti- SSA/SSB
mixed connective tissue diseaseanti-U1 RNP
Autoimmune hepatitisanti smooth muscle
Churgstrauss syndromep-ANCA


Question Answer
IL11 Oprelvekinthrombocytopenia
filgrastimincrease granulocyte
sargramostimincrease macrophage
muromonab CD3transplant rejection
crohn's disease/RA/Psoriatic

Spleen and Thymus

Question Answer
Macrophages found where?red pulp
T cells found where?periarterial lymphatic sheath of white pulp of spleen
lymph node paracortex(not well developed in DiGeorge syndrome)
thymus cortex: immature T cells
thymus medulla: mature T cells
B cells found where?white pulp of spleen
lymph node follicle
Macrophages remove what?encapsulated bacteria (SHiN SKiS)
How does splenic dysfunction ↑ susceptibility to encapsulated organisms?↓ IgM → ↓ complement activation → ↓ C3b opsonization → ↑ susceptibility to SHiN SKiS
What would you find postsplenectomy?Howell-Jolly bodies (nuclear remnants)
Target cells
Where do T-cells mature and differentiate?Thymus
Where do B cell mature and differentiate?Bone marrow
Embryo origination of thymusepithelium of 3rd brachial pouches
Cortex of thymus containsimmature T cells
double negative
double positive (have both CD4+ and CD8+)
Medulla of thymus containsmature T cells
epithelial reticular cells containing Hassall's corpuscles
Positive selection occurs where?positive selection happens first, selects T cells which recognize self MHCs
corticomedullaey junction
T cells expressing TCRs capable of binding surface self MHC molecules survive
Negative selection occurs where?negative selection selects T cells which do not recognizes self antigens
corticomedullaey junction
T cells expressing TCRs with high affinity for self anitgens undergo apoptosis


Question Answer
Cells of the innate immunityneutrophils, macrophages, dendritic cells, natural killer cells (lymphoid origin) and complement
Cells of the adaptive immunityT cells, B cells, and circulating antibody
MHC stands for what and is encoded by what?major histocompatibility complex
Encoded by human leukocyte antigen (HLA) genes
MHC Iab2
Binds TCR and CD8
Expressed on all nucleated cells (not RBCs)
Antigen is loaded in RER with mostly intracellular peptides
Binds TCR and CD4
Expressed only on antigen-presenting cells (APCs)
Antigen is loaded following release of invariant chain in an acidified endosome
HLA subtype assoc with what?HLA B27: IBD, RA, Psoriasis, Reiter syndrome, ankylosing spondylitis, uveitis
NK cells do whatUse perforin and granzymes to induce apoptosis of virally infected cells and tumor cells

Kill when there is a nonspecific activation signal on target cell or
an absence of class 1 MHC on target cell surface (less MHCI on cells>>>NK cell attack

They are the only lymphocyte member of the innate immune system

NK cells' activity is enhanced by IL-12, IFN-B, and IFN-a (HBV therapy)

IFN-a: Stimulation of NK cell mediated cytotoxic killing activity


Question Answer
Th1 helper T cell secretes what and activates what?IFN-gamma
Activates macrophages
Th2 helper T cell secretes what and activates what?IL-4,5,10,13
Recruits eosinophils for parasite defense and promostes IgE production by B cells
Th1/Th2 - what inhibits what?Th1 inhibits Th2 with IFN-gamma
Th2 inhibits Th1 with IL-4 and IL-10
CD40L on T cellsCD40 on B cells (and macrophages) >>>class switching
B7 on APC cells (macrophage and B cells´╝ëCD28 on CD4+ T cells
hyperacute rejection of a renal transplantantidonor antibody
skin rash and joint pain after treatment with trimethoprim/sulfamethoxazoleserum sickness, type III hpersensitivity, hypocomplementemia, decreased serum C3
Ig EIL-4 KA35-5
Ig AIL-5


Question Answer
Leukocyte transmigrationPECAM-1(CD31) on endothelium
ICAM-1 on endotheliumCD18/Integrin b2/LFA-1/MAC-1
Firm adhesion

Antibody structure and function

Question Answer
Variable part of L and H chains do what?recognize antigens
Fc portion of IgM and IgG does what?fixes complement
Fab=VH+CH1Antigen-Binding fragment
the variable region determines idiotype
only 1 antigenic specificity expressed per B cell
Fc=CH2+CH3Complement binding at CH2 (IgG + IgM only)
Determines isotype (IgM, IgD, etc)
Antibody diversity is generated byRandom recombination of VJ (light chain) or V(D)J (heavy chain) genes
Somatic hypermutation (following antigen stimulation)
Addition of nucleotides to DNA during recombination by terminal deoxynucleotidyl transferase

Immunoglobulin isotypes

Question Answer
Mature B lymphocytes express what?IgM and IgD
Isotype switching involves what?Gene rearrangement - mediated by cytokines and CD40 ligand
AntibodyIgG 650-1500 mg/dl
IgA 79-370 mg/dl
IgE 0-380 mg/dl
IgM 40-345 mg/dl, fixes complement, do not cross the placenta, immediate response
IgA deficiencye.g IgA 10mg/dl
sinopulmonary infection
increased atopic allergy (complement deficiency: immune complex disease)
Prevents attachment of bacteria and viruses to mucous membranes
Does not fix complement
Monomer in circulation or dimer when secreted
Found in secretions (tears, saliva, mucus) and early breast milk (colostrum)
Thymus-independent antigensLPS or polysaccharide capsular antigens
stimulate release of antibodies without producing immunologic memory
Thymus-dependent antigensContain a protein component (diphtheria vaccine)
Class switching
contact of B cells with Th cells (CD40-CD40L)


Question Answer
Transplantsallograft: different member of same species
autograft: individual's own tissue
syngeneic graft/isograft: identical twins
xenograft:different species


Question Answer
ActivationClassic pathway - IgG or IgM mediated
Alternate pthwy - microbe surface molecules
Lectin pthwy - mannose or other sugars on microbe surface
also helps clear immune complexes
C3a, C5aanaphylaxis
neutrophil chemoattractantc5a and IL8 (Secreted by macrophages)
Stimulates neutrophil migration to the site of inflammation: Leukotriene B4, 5-HETE, C5a
C5b-9cytolysis by MAC.
gram-negative bacteria→ recurrent Neisseria bacteremia
InhibitorsDecay-accelerating factor→ complement-mediated lysis of RBC's and paroxysmal nocturnal hemoglobinuria (PNH)
C1 esterase inhibitor
prevents complement activation on self cells (RBCs)
C1 esterase inhibitor deficiency→ hereditary angioedema
ACE inhibitors are contraindicated
C3 deficiency→ severe, recurrent pyogenic sinus and respiratory tract infections
↑ susceptibility to type III hypersensitivity reactions


Question Answer
IFN-rTh1 cells secrets and activates macrophages and Th1 cells
Suppresses Th2 cells
Cytokines from macrophagesIL1,6,8,12, TNF-a
IL1: fever
IL12: activates NK cells, induces T cell differentiation
*IL12 R deficiency>>>reduced IFNr
Cytokines from all T cellsIL-2: stimulate T cells
IL3: stimulates bone marrow growth and differentiation
Cytokines from Th1 cellsInterferon-gamma>>>Activate macrophage, CD8+
Cytokines from Th2 cellsIL-4,5,6,10
IL10 and TGFb>>>Downregulating cytokines
Interferonsinduce production of ribonuclease → inhibits viral protein synthesis by degrading viral mRNA (but not host mRNA)
IFN-a: Stimulation of NK cell mediated cytotoxic killing activity


Question Answer
B cellsIg
CD21:receptor for EBV
Endotoxins/LPS action from Gram-negative bacteria
Binds to CD14 → directly stimulating macrophages
Th cells are not involved



Fc and C3b receptors (enhanced phagocytosis)
NK cellsCD16: Binds Fc of IgG
CD56: unique marker for NK cells
cleared by NK cells Not Tc cells due to the lack of MHC on RBC
Tc cells depend on recognition of MHC I on infected cells, could not recognize RBC.
TCRbinds antigen-MHC complex
CD3assoc w TCR for signal transduction
CD28binds B7 on APC


Question Answer
immunodeficiency1) reduced B cell No>>>bruton's agammaglobulinemia: x linked recessive, tyrosine kinase gene, no B cells
2) hyperIgM: no CD40L on T cells, no B classs switching
3) CVID: IgA def>>>recurrent URI, otitis media and GI infection, hypersensitity against blood products because of recognizing lgA as foreign

reduced T cell No. or T cell dysfunction
1) Digeorge syndrome: KA34/16
2) IL12 R deficiency or T cells do not produce IFNr (job's syndrome) >>>no neutrophil response

SCID: Severe combined immunodeficiency, x-linked(IL-2R defect) or adenosine deamine deficiency, lots of infections , diarrhea, ago<6 month
wiskott Aldrich: x linked, thrombocytopenic purpura, infection, eczema, low IgM
Leukocyte adhension def: integrin CD18>>>Delayed umbilical cord, poor wound healing
chediak higashi: recurrent infection, albinism, neuropathy (nystagmus)
CGD: NAPDH oxidase>>>low ROS>>>CATALASE+
Sacroiliitis Reactive arthritis
deficient DNA repair enzymes--------------------------
ataxia telangiectasia: difficult walking (cerebellar atrophy), respiratory infection (IgA deficiency), radiation induced genetic mutation

xeroderma pigmentosum: Thymine dimer when UV radiation>>>skin cancer, corneal ulcerations

fanconi anemia
recurrent infections by NeisseriaInability to form the membrane attack complex
diffuse itching, skin rash and bronchospasm after blood transfusion selective immunoglobulin deficiency
Combined immune deficiencySCID
low platelet, long bleed time, skin rash, respiratory infections, Low IgMWickott Aldrich syndrome
x linked immune deficiency wickott Aldrich syndrome/bruton's/SCID
Lymph node follicleB cell isotype switching
kid, abdominal pain, arthralgias, stool blood, proteinuria skin lesionsHenoch schonlein purpura, immune complexes, High IgA
Systemic Mastocytosis------------------------
a disorder where mast cells are abnormally increased in multiple organs including the bone marrow. Mast cells are immune cells that produce a variety of mediators, such as histamine, that are important in the body's allergic responses.

several month history of pruritus, rash flushing and abdominal cramps, small bowel biopsy demonstrates nests of mast cells within the mucosa

systemic mastocytosis>>>mast cell proliferation in the bone marrow and in other organs>>>increased histamine secretion>>>gastric acid secretion increases (gastric ulceration)>>>inactivates pancreatic and intestinal enzymes>>>diarrhea