okay so welcome to another MedCram lecture we're talking about liver
function tests it's the third lecture where we 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 is an oral transmission so you don't get it by
blood you get it by the soil not washing their hands and then getting into the
food and then there's sort of a fecal oral transmission you get it but because
this is the liver you're going to see an increased amount of alt over ast both go
up but you're going to 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 and T
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 going to 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 going to have antibodies that are going to be made against the surface
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 IgM
you should have both of those so again the IgM antibodies of 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 going to see as much of an increase here but
again the key point here is the ast is going to be less and increased 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 anti 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 okay 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 is that interesting and obviously here instead
of intravenous drug use we're going to 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 going to be
really upset with that and it's going to tell you that and so what you're going
to see is humongous raises 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 going to have blood pressures here in the 50s / 30s or
something really bad like that or a code situation and again you're going to 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 is going to be based
on 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
mash 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 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 ASD 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 going to be of exclusion you
want to just make sure that you're not just 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 itis again it's in the liver they're
going to 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 going to be very difficult
to say that this is all related to alcohol disease so look for positive
Auto antibodies and to nuclear antibodies but specifically the answer
they're looking for is anti smooth muscle antibodies ok humic row mitosis
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 going to 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 T IBC you're going to get something
greater than 55 percent 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 got a 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
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
going to 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 h ER 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 serum and plasma ratio okay and now the one that's most near and dear to my
heart is alpha 1-antitrypsin you specifically 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 law in the liver and you'll see these past positive pass
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 going to have COPD asthma certainly if they smoke very
early in life if they don't smoke they'll have COPD later in life and
they'll 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 you check
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
you