Let us now continue.
Now, electron microscopy is then going to
help you identify few things. Light microscopy
may have shown you or increased your suspicion
of glomerular disease. You do electron microscopy.
What color would this be? Black and white.
Fusion of your podocytes. Close your eyes.
Think about your podocytes. Where are you?
You are on the side of the urine. You are
on the other side of the glomerular basement
membrane and that podocyte has food processes
in which they then become fused. Prototype,
minimal changed disease. On electron microscopy,
you actually find the fusion of the food processes.
Such a finding would never take place at microscopy.
What about in immunofluorescence? What does immunofluorescence
fluoresced or recognized? Immunoglobulins.
The fusion of food processes has nothing to
do with immunoglobulins, does it? No. So,
therefore, why would you ever want to use
immunofluorescence when you have fusion of
podocytes? You don't. Use common sense. Know
as to what information that you are getting.
Why it has been given? That it would then
lead you into your diagnosis. Damage to what?
Your visceral epithelial cell a.k.a. podocyte.
What else? Well with electron microscopy, apart
from the fusion of your podocytes, it detects
IC, stands for immune complex. So, immune
complex deposition, just takes us back to our
previous discussion with immunofluorescence.
So, for example, let us say that electron
microscopy did show you deposits, where? Maybe,
on the side of the epithelial. Maybe, on the
side of the endothelial. The electron microscopy
shows you such dark deposits. Then on immunofluorescence
what kind of pattern is this known as? Granular.
You go as far as that from now, for your boards and wards ,
you are in fantastic shape.
Now as you go in further specialization, let us
say in pathology and understand there's certain
techniques that you can use along with immunofluorescence
that will then tell you if you are on the
side of your endo or epithelial. The sites
are designated as follows. Now pay attention
here. Subendothelial. You are on the side
of the blood. If you are underneath subendothelial,
you will be between as the name says here
or as the statements say here between the
glomerular basement membrane and the endothelial
cell. Is that clear? If it is isn't, I would
recommen that you go back and take a look
at the picture in which we walked through normal
electron microscopy, identify glomerular basement
membrane and the endothelial cell and what
would you find in electron microscopy? A dark
deposit. Now, what if you it did with the immunofluorescence?
Is that even relevant? Of course, it is because
it is immune complex. And here how would you
then describe the pattern? Granular. Another
one for electron mircroscopy. However, this
will be subepithelial, so what are you under?
Your podocyte and your glomerular basement
membrane. This is once again an immune complex.
On immunofluorescence, what kind of pattern
is this called again? Very good, granular. Or you can
have issues within the basement membrane.
For example, you have heard of membranous
glomerulonephritis, haven’t you? MGN, membranous
glomerulonephritis. What does that mean to
you? Intramembranous issues, electron microscopy
or maybe mesangial. Mesangial would be much
better seen in terms of its changes if you
did a light microscopy with H&E stain. The
basis of what you need to know in terms of
moving forward, laboratory investigations
and biopsy is here in these discussions.
It is only once you have mastered the foundation
of your investigation, you will then move
into the particular pathologies. To summarize,
three major biopsies stainings, we have our
light microscopy H&E, we have immunoflurorescence,
and number 3 electron microscopy. Let's move on.