Nephrotic vs. Nephritic
Syndrome
Here’s one of those
things in pathology that will lead you to pull all your hair out: what is the
difference between nephrotic and nephritic syndrome?
Ugh. They both involve
the kidney, they both are syndromes, so they’re probably both constellations of
findings, and the names are maddeningly similar except for one stinking vowel. How
can a person be expected to memorize these things?
Let’s start with the
main features of each syndrome. We shall pick four features for each, since it is
really hard to remember more than four of anything.
Nephrotic
syndrome:
1.
Massive proteinuria
2.
Hypoalbuminemia
3.
Edema
4.
Hyperlipidemia/hyperlipiduria
Nephritic
syndrome:
1.
Hematuria
2.
Oliguria
3. Azotemia
4. Hypertension
How do you make these
lists hang together in a way that you can remember?
First, let’s take
nephrotic syndrome. The thing to remember for this one is massive proteinuria. You
might do this by remembering that nephrotic and protein both have an “o” in them. The massive proteinuria in these patients leads to
hypoalbuminemia (they are peeing out albumin!), which results in edema (the
oncotic pressure in the blood goes down, and fluid leaks out of the vasculature
into the surrounding tissue). So right there, you have three of the four
features, just by remembering one. The cause of the last feature, hyperlipidemia/hyperlipiduria,
is less well understood, so you are just going to have to memorize that one. As
an aside, nephrotic syndrome is often more dangerous than nephritic syndrome, so
you might want to think of this syndrome as the “oh sh*t” syndrome (again – nephrotic has an o in it, nephritic does not). Crude,
but if it works, who cares?
In nephritic syndrome, there
is some proteinuria and edema, but it’s not nearly as severe as in nephrotic
syndrome. The thing with nephritic syndrome is that the lesions causing it all
have increased cellularity within the glomeruli, accompanied by a leukocytic
infiltrate (hence the suffix -itic). The
inflammation injures capillary walls, permitting escape of red cells into urine.
Hemodynamic changes cause a decreased glomerular filtration rate (manifested
clinically as oliguria and azotemia). The hypertension seen in nephritic
syndrome is probably a result of fluid retention and increased renin released
from ischemic kidneys.
If you really want to
pare it down – if you only have enough brain space to remember one feature for
each disorder – remember that nephrotic syndrome is characterized by massive
proteinuria (the “o” in nephrotic), and nephritic
syndrome is characterized by inflammation (the “-itic” in nephritic). Then at least you’ll have a shot at remembering the
other features.
