okay so welcome to another MedCram lecture we're talking about liver
function tests it's the third lecture where we could talk about actual
diseases and I wanted to break them up into acute liver diseases chronic and
finally cholestatic so let's get started okay so here I've made a table of some
of the characteristics of hepatitis in the acute form let's talk about
hepatitis A remember that hepatitis A is an oral transmission so you don't get it
by blood you get it by so I'm not washing their hands and then getting
into the food and then there's some sort of a fecal oral transmission you get it
but because this is the liver you're gonna see an increased amount of alt
over ast both go up but you're gonna see more of an alt type of bound up over the
ast and so how are you going to diagnose this remember it's the eye G M anti
hepatitis A virus okay so that's how you make the diagnosis now with hepatitis B
on the other hand it's not oral but it's intravenous intravenous or body fluid
okay and in this situation it's very similar to hepatitis A and that the alt
is going to be higher than the ast because this is the liver that's being
attacked and not muscle or something else with hepatitis B remember there's
different antigens there's surface antigens and there's cor antigens and
that's important because if you get an immunization you're gonna have
antibodies against the surface antigen so if I could draw a little example here
if this is the virus particle the blue is the surface and the core is the green
the core is the actual viral particle so when they give a vaccine they're just
using the blue portion of the virus the non-infectious so you're gonna have
antibodies that are gonna be made against the surf
antigen so you so if you have an immunization you should be surface
antibody positive but you should be core antibody negative because they never
gave you the core and so what this means is that you should the IgM antibody to
the hepatitis B core antigen should be positive if you actually have the
infection let me restate that here so the i GM core antibody is positive again
the IgM antibody to the hepatitis B core antigen is positive that's called the
IGM anti-hbc c stands for the core and you should also have it positive to the
surface antigen so both of those should be positive okay because in an actual
infection you're getting the surface and you're also getting the core so you
should have i GM you should have both of those so again the IgM antibodies at the
hepatitis B core antigen and to the hepatitis B surface antigen both should
be positive okay what about hepatitis C again hepatitis C
is actually a little bit more chronic and so you're not gonna see as much of
an increase here but again the key point here is the ast is gonna be less an
increase than the alt again this is intravenous drug use or IV DEA abuse
okay there's other things that are associated with this like tattoos also
sharing razors multiple sex partners these sorts of things can increase the
risk of spreading hepatitis C now how do you check for that it's very simple it's
simply the aunty HCV antibody into IgM you could also check for the hepatitis C
virus RNA within the first three months of the exposure you should have an
antibody reaction though alright let's talk about alcohol now
whereas before the alt was higher than the ASD because this is the liver be
aware that in alcohol they're about the same or you might even see that the ast
is going to be higher than the alt isn't that interesting and obviously here
instead of intravenous drug use we're gonna get alcohol use so that's that's
obviously very important difference there obviously you want to make sure
that there's not other things going on here so the diagnosis is basically based
based on history what about ischemic now remember an
ischemic you're getting no blood flow to the liver so the liver is gonna be
really upset with that and it's gonna tell you that and so what you're gonna
see is humongous raises in the ast and the alt and we're talking several
thousand here okay so they really go up in ischemic disease and obviously you're
gonna have blood pressures here in the 50s / 30s or something really bad like
that or a code situation and again you're gonna be ruling out other things
here but if you see this go up and shoot up pretty quickly I want you to think of
ischemia and you just again it's gonna be based on the the history okay let's
talk about the chronic diseases now obviously you can get chronic hepatitis
B and C and you don't get chronic hepatitis A or it's very rare so I left
those off of here basically they look identical as to the acute situation
except the liver enzymes are not as elevated let's talk about Nash probably
one of the most common it stands for non-alcoholic steatohepatitis basically
these patients are fat obese so you're talking about patients with for instance
the metabolic syndrome insulin resistance hypertriglyceridemia and that
in the history you're going to basically get for the diagnosis is that of
exclusion you certainly don't want to just look at someone say they're fat and
that's why you've got Nash but these type of patients what do they look like
these patients are liver patients so they're going to have a slightly
increased alt over that of the AST but the alt will be higher than the
but it'll be it'll be elevated now as we said with alcohol it's very it's just
backwards the alt is high but the ast is what's elevated and again the history is
going to be that of EtOH and a guess it's also gonna be of exclusion you want
to just make sure that you're not just as subscribing somebody to the old
alcohol reason for their liver disease make sure that even though they're
drinking make sure you rule out the other things autoimmune hepatitis that's
that's the reason why we need to rule this out if you have a middle-aged woman
who drinks a lot you certainly don't want to say that it's due to just for
drinking because it could be due to autoimmune disease these are the type of
patients that get autoimmune disease these young women so because it's an
autoimmune hepatitis again it's in the liver they're gonna have a higher alt
than ast so the history in this is that they're young women that's the type of
people who get these autoimmune diseases and the thing here that you got to know
is this this is for boards and it's the anti smooth muscle antibody if that's
positive it's gonna be very difficult to say that this is all related to alcohol
disease so look for positive Auto antibodies anti-nuclear antibodies but
specifically the answer they're looking for is anti smooth muscle antibodies ok
hemochromatosis this is uncommon in women it's usually because why they have
periods and they lose iron so they it's very hard to store up with iron but the
history here is that it's typically in men and what are we gonna see here well
if you take the ferritin level and the iron saturation that's the where you
take the iron the serum iron and divided by the TI BC you're gonna get something
greater than 55% and usually you're ferritin level is greater than a
thousand so you're off the charts with this and of course the history is that
of something called bronze diabetes and this shows up on test a lot and the
reason does is because it's going to very specific presentation basically
iron infiltrates a lot of the endocrine organs of the body the iron infiltrates
the pituitary okay so they can get pituitary problems it infiltrates the
pancreas so what do they get they get diabetes it infiltrates the heart so
they get what and CHF or some sort of constrictive cardiomyopathy okay so look
for this patient with diabetes who has a bronze look to themselves now
there's an iron metabolism deficiency that you should know it is on chromosome
six and how do you remember that I remember that iron comes in a 2 plus
form and also in a 3 plus form the Pharos and the ferric form and I know
that 2 times 3 is equal to 6 so that's how I remember it's on chromosome 6 I
don't think they will ever ask you that but you can certainly impress your
friends with that bit of knowledge ok what about Wilson's disease I think
Wilson's disease showed up on a famous television show once and those of us who
studied knew what the diagnosis was before the end of the show you're gonna
have increased alt and ast the history here with Wilson's disease is that
they're young they get this kind of korea form movement disorder and
psychiatric disease but the key here is this thing's called the kaiser ka y ser
Fleischer f.l.e.i.j.a sche are rings so google that or look that up on the
internet and see what kaiser Fleischer rings are in the eyes and you will see
that and the key here is not a high but a low zero plasmon and why is that
because it's trying to suck up all the copper this is a abnormal copper
deposition so you get hemolysis and actually you get a low alch foss and a
low cerumen plasmon ratio okay and now the one that's most near and dear to my
heart is alpha 1-antitrypsin these but typically we see this with patients
with lung disease remember antitrypsin alpha-1 antitrypsin is an enzyme that is
in your lungs it's made in your liver as well and what it does is it protects
these elastase --is from breaking your elastin fibers and so if you don't make
alpha 1-antitrypsin you have something called alpha 1-antitrypsin deficiency
and you tend to get emphysema more quickly well that's not the only thing
that can happen you can get a buildup of this abnormal protein in the liver and
you'll see these past positive paths positive granules in the liver and you
will get liver disease it's a very kind of a low-level liver disease so you're
not going to see it going very high but on the history you're gonna have COPD
asthma certainly if they smoke very early in life if they don't smoke
they'll have COPD later in life in the scratch your head say well how did I get
the COPD I've never smoked well get an alpha 1-antitrypsin level the thing that
you should know there is the worst form of it is the p i--
z z allele okay and the normal is the mm but the z z is the worst
and that's homozygote recessive okay so this is autosomal recessive autosomal
recessive inheritance and so how do you make the diagnosis you don't obviously
do a liver biopsy first off but you simply get an alpha 1-antitrypsin level
and then have them see a liver doc okay so let's talk about next the
characteristics of cholestatic liver disease and for that join me for the
next lecture number four