In this lecture, we’re going to discuss
proteinuria and the nephrotic syndrome.
We have another lecture where we discussed
hematuria and glomerulonephritis.
So here’s a typical case for you,
a 7-year-old girl presents with
complaints of, say, dysuria.
She has been taking bubble baths and you
suspect, this a simple case of vaginitis.
On exam, your
suspicions are confirmed
and as she’s leaving, the nurse
pulls you inside and says,
"Wait, wait, wait not so fast."
"We have dipped her
urine to check for UTI
and she doesn’t have UTI but we did notice
she has +3 protein in her dipstick."
Here’s an asymptomatic child who
has some protein in her urine.
What do we do?
Well, let’s look at proteinuria.
This is when you have protein in your urine
and it's technically defined as more
than 100 mg per square meter per day,
very challenging to make that calculation.
So this translates roughly to a dipstick
value of +3 or +4 on the dipstick.
Around 10% of children will
dip positive for urine,
but only 0.1% have
So remember that a mild
positive urine dip for protein
is probably nothing
to worry about.
So here’s a comparison where you can refer
for how much protein is on the dipstick
and approximately how much
that actually works out to be
in terms of concentration
of protein in the urine.
The idea here is that point
+3 and +4 tend to correlate
to more than 1 gram of protein per day lost
in the urine which is usually pathologic.
Okay, so if you want to
test for proteinuria,
one way we classically have taught people
to do is to obtain a 24-hour urine protein.
This might be feasible in adults,
but in children this is just
practically very challenging.
They forget to pee in the cup or they
go to school, it’s a little bit harder.
So what we usually use for children
is a protein to creatinine ratio.
The protein-creatinine ratio allows us to
correct for the concentration of the urine
to give an estimation on whether there is too
much protein or not in that urine sample.
It’s common for children
under twp years of age
to have a higher protein
to creatinine ratio.
So we consider an abnormal
value more than 0.5.
The reason is that children and babies do
tend to spill a little bit more protein
because of immature glomeruli.
In children over
two years of age,
we consider more than
0.2 to be abnormal.
For patients with frank nephrotic syndrome,
this value is usually more than 2.
So a value more than 2 tells you
something is substantially going wrong.
So when we think of the
pathology of proteinuria,
we think of 3 major types.
Patients may have benign
They may have a tubular
source of proteinuria.
Or they may have a glomerular
source of proteinuria.
I want to look at these three
Let’s start with benign transient
causes of proteinuria.
Among these, there are two types:
Transient and orthostatic.
Transient proteinuria is common
in patients who are having fever,
in patients who had seizure,
in patients who are stressed,
and patients who are dehydrated or in
patient who have a lot of exercise.
All of these things can cause
a transient proteinuria.
This is a benign condition and will
resolve when the stressor is resolved.
Orthostatic proteinuria is a phenomenon
that's most specific to school aged children.
This is an asymptomatic proteinuria such
as our case at the beginning of this talk.
There are no comorbidities.
These children have
no other problems.
And if you obtain a first morning
void, right when they wake up,
it will not have protein.
These patients had protein
from having stood up all day;
hence, the word