v2024/ v2025 vUPDATE) vADVANCED
vPATHOPHYSIOLOGY v| vQUESTIONS vAND
vVERIFIED vANSWERS| v100% vCORRECT v|
GRADE vA v– vCHAMBERLAIN
Hypersensitivity: vType v1 v- vanswersType v1: vAllergic vreaction, vMediated vby vIgE,
vInflammation vdue vto vmast vcell vdegranulation
Local vsymptoms: v
-itching
-rash
Systemic vsymptoms: v
-wheezing
Most vdangerous v= vanaphylactic vreaction
systemic vresponse vof vhypotension, vsevere vbronchoconstriction
Main vtreatment: vepinephrine vreverses vthe veffects
Hypersensitivity: vType v2 v- vanswersType v2: vCytotoxic vreaction; vtissue vspecific v(ex:
vthyroid vtissue)
Macrophages vare vthe vprimary veffectors vcells vinvolved
Can vcause vtissue vdamage vor valter vfunction
Grave's vdisease v(hyperthyroidism) v- vexample vof valtering vthyroid vfunction, vbut vdoes
vnot vdestroy vthyroid vtissue
Incompatible vblood vtype- vexample vof vcell/tissue vdamage vthat voccurs; vsevere
vtransfusion vreaction voccurs vand vthe vtransfused verythrocytes vare vdestroyed vby
vagglutination vor vcomplement-mediated vlysis.
Type v1 vHypersensitivity vVS. vType v2 vHypersensitivity v- vanswersType v1
vHypersensitivity
Organ vSpecific
Antibody vbinds vto vthe vantigen von vthe vcell vsurface
Type v2 vHypersensitivity
Not vOrgan vSpecific
Antibody vbinds vto vthe vsoluble vantigen voutside vthe vcell vsurface vthat vwas vreleased
vinto vthe vblood vor vbody vfluids, vand vthe vcomplex vis vthen vdeposited vin vthe vtissues
, Hypersensitivity: vType v3 v- vExamples v- vanswersRheumatoid varthritis:
vAntigen/antibodies vare vdeposited vin vthe vjoints
Systemic vLupus vErythematosus v(SLE)- vvery vclosely vrelated vto vautoimmunity-
vantigen/antibodies vdeposit vin vorgans vthat vcause vtissue vdamage
Hypersensitivity: vType v4 v- vanswersDelayed vresponse
Does vnot vinvolve vantigen/antibody vcomplexes vlike vTypes v1, v2 vand v3
Is vT-cell vmediated
Differentiating vBetween vthe vRash vof va vType v1 vvs. vType v4 vReaction: v-
vanswersType v1: vImmediate vhypersensitivity vreactions, vtermed vatopic vdermatitis, vare
vusually vcharacterized vby vwidely vdistributed vlesions
Type v4: vContact vdermatitis v(delayed vhypersensitivity) vconsists vof vlesions vonly vat
vthe vsite vof vcontact vwith vthe vallergen
The vkey vdeterminant vis vthe vtiming vof vthe vrash: v
-Type v1 v= vImmediate v
-Type v4 v= vDelayed: vSeveral vdays vfollowing vcontact, vex vwould vbe vpoison vivy
Treatment vof vType v4 vRash v- vanswersA vnon-severe vcase vof vcontact vdermatitis
vwould vbe vtreated vwith vtopical vcorticosteroid. v
Why vnot vepinephrine vor vantihistamines? v
-Epinephrine vis vfor vemergent vType v1 vanaphylactic vreactions. vAntihistamines vact von
vthe vH1 vreceptors. vType v4 vdoes vnot vinvolve vmast vcells vand vH1 vreceptors. v
Antibiotics vnot vappropriate vsince vnot van vinfection
Autoimmunity v- vanswersAutoimmune vdisease vcan vbe vfamilial, vAffected vfamily
vmembers vmay vnot vall vdevelop vthe vsame vdisease, vbut vseveral vmembers vmay vhave
vdifferent vdisorders vcharacterized vby va vvariety vof vhypersensitivity vreactions, vThese
vinclude vautoimmune vand vallergic vreactions
Associations vwith vparticular vautoimmune vdiseases vhave vbeen videntified vfor va
vvariety vof vmajor vhistocompatibility vcomplex v(MHC) valleles vor vnon-MHC vgenes
Alloimmunity v- vanswersGeneral vterm vused vto vdescribe vwhen van vindividual's
vimmune vsystem vreacts vagainst vantigens von vthe vtissues vof vother vmembers vof vthe
vsame vspecies. v
Examples: vNeonatal vdisease vwhere vthe vmaternal vimmune vsystem vbecomes
vsensitized vagainst vantigens vexpressed vby vthe vfetus, vTransplant vrejection,
vTransfusion vreaction