hello and welcome back to another future
doc house production let's continue our
journey on hyper sensitivity we are on
type 2 hypersensitivity and type 2
hypersensitivity in a nutshell is
antibody mediated hypersensitivity what
does that mean isn't IgE in type 1
hypersensitivity an antibody yes but
this antibody is an autoantibody not
the Autobots in transformers but
autoantibodies and what is Autoantibodies
mean Autoantibodies means that these
antibodies attack human tissue your own
tissue your self tissue auto self self
tissue and this is bad this is a bad thing
alright these are produced by again B
cells and plasma cells here we go here's
the how this happens antigen say the
antigens can be drugs can be you know so so some drug allergies antigens
can be say different type of blood in
blood transfusion now this antigen
triggers an immune response and this
immune response okay causes antibodies
to be created by these cells these
antibodies are cross-reactive with your
own tissue hence they're called Autoantibodies and because they're cross
reactive to your tissue they bind to the
Fc receptors of your tissues causing
tissue damage and allergies basically in
a sense so that's the difference between
type 1 and type 2 know that alright
let's do this so how does the
autoantibodies damage your damaged yourself damage your body
opsonization the antigens can cause
opsonization of the cells the
antigens can't activate the complement
system which you will learn in immunology and
in in turn recruit neutrophils and
macrophages that will damage the cells
your own cells and they could also bind
to cellular receptors like I said by
binding to the cellular receptors they
can cause all these things as well as
inhibit stuff for example in diabetics
and diabetes if they bind to the insulin
receptors then then you have insulin
resistant diabetes so that's that's a
possibility that can happen with Autoantibodies all right some diseases that
happens so we've got HDNB so when
you get in vignette you're gonna get
these diseases you can go oh yeah type 2
diabetes sorry type 2 hypersensitivity
okay and type 2 hypersensitivity that's
easy I got this right that would be an
easy question they give you a disease
you know it's a type 2 hypersensitive
the more difficult questions usually
relate to pathology okay pathophysiology
so they're gonna give you the disease's
and you're gonna they're gonna ask you
some questions about the disease okay
that's gonna be a more difficult
question but as far as immunology is
concerned they're gonna only ask you
about type 2 hypersensitivity about Autoantibodies damages can occur through
these mechanisms optimization activation of complement system or binding of
cellular receptors so it's not
that difficult so let's briefly go
through some of the diseases because I
can't teach you each one of these
disease is its own video and we're just
gonna summarize them as much as possible
the ones that I talked about are the
important diseases I would like you to
dive in dive into further after this
video on your own
use Wikipedia use your books textbooks
whatever HDNB hemolytic disease of the
newborn also known as the
erythroblastosis fetalis and this
is the where the IgG from the mother
crosses the placenta and starts
attacking the the antigen on the fetal
RBCs causing hemolysis and it's not
very good for the child RhoGAM is
RhoGAM is usually given to the pregnant
mother if there is incompatibility of
the blood look it up it's a very
important disease you know we could
spend a whole we can spend more time on
it I'm gonna quickly go through this
acute rheumatic fever I will talk
about acute rheumatic fever in the video
on streptococcus so look for it in that
video once it's created or when it is
look for it on in the library
streptococcus cell wall antigens antibodies
that would be used to fight these
streptococcal 
cell wall you know reacts with your
heart cells your myocardial cells and
antigens so this antibody that's
supposed to attack this antigen on the
streptococcus cell wall also attacks
myocardial antigens damaging the cell
your heart cells autoimmune ITP this
basically is where the antibodies
inhibit platelets and and if you don't
have platelets then you start bleeding
so this is ITP autoimmune ITP look it up
it's quite interesting you've got
transfusion reactions blood transfusion
reactions same thing with the HDNB
kind of mechanism
you've got goodpasture syndrome which
I love to mention goodpasture syndrome
because type 4 collagen this is the
collagen that's affected by the
antibodies and type 4 4 is floor floor is
basement membrane so the type 4 collagen
for the basement membrane this is what
it gets affected when you affect a
basement membrane say of the kindey 
glomeruli glomeruli and
the lung alveoli then you've got
diseases this goodpasture syndrome
disease which usually affects the kidneys and
the lungs related to antibodies against
type 4 collagen
myasthenia gravis you've got
acetylcholine receptors where antibodies
bind to the acetylcholine receptors
where acetylcholine cannot bind to
those receptors causing weak muscles
look it up it's uh another very
interesting disease Graves disease
same thing with TH with TSH receptors
thyroid stimulating hormone receptors
and initially you start off with
hyperthyroidism and then end up with
hypothyroidism interesting another
interesting disease look it up and these
two that I want to mention quickly type
to insulin resistance diabetes I mention
that earlier where the autoantibodies
bind to these insulin receptors and
insulin can't get to him you have
diabetes and of course pernicious anemia
yeah I forgot about pernicious yeah it's
there so look it up alright if you liked
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