Question about nephritic/nephrotic

[anbuitachi]

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So nephrotic is >3.5g/day of protein loss in urine and no rbc.

while nephritic is <3.5 g/day + RBC.

I'm confused to if nephritic glomerulus can let out RBC which are bigger than proteins... why is it releasing less protein in the urine???

And if someone has >3.5 g/day of protein loss, AND rbc loss.. then what is that called?

Thanks!

 

[Myxedema]

It is not just about size, it is about the chemical and electrical properties of the GBM. For instance, GBM contains polyanions, which repel anionic proteins like albumin. In nephrotic syndrome, loss of these properties of GBM leads to massive protein loss.
Since nephrotic syndrome can present with hematuria as well, presence of RBCs + proteinuria in the nephrotic range (>3.5 g/day) will still be nephrotic syndrome.

 

[Jamiu22]

It is not just about size, it is about the chemical and electrical properties of the GBM. For instance, GBM contains polyanions, which repel anionic proteins like albumin. In nephrotic syndrome, loss of these properties of GBM leads to massive protein loss.
Since nephrotic syndrome can present with hematuria as well, presence of RBCs + proteinuria in the nephrotic range (>3.5 g/day) will still be nephrotic syndrome.

spot on!

 

[anbuitachi]

Thankss!

 

[anbuitachi]

can someone explain to me what this means?

The pathogenetic mechanism(s) of edema formation in nephrotic syndrome is:
Low oncotic pressure causing secondary renal salt retention. AND
Primary renal retention of salt.

What exactly does primary renal salt retention mean here in terms of causing nephrotic syndrome.. ?

 

[Ian]

Could it because of a generalized renal injury affecting the glomerulus that causes protein loss as well as affecting renal tubular function? Can't think of a mechanism that ties the 2 up neatly. Interested in a better answer too.

 

[anbuitachi]

Could it because of a generalized renal injury affecting the glomerulus that causes protein loss as well as affecting renal tubular function? Can't think of a mechanism that ties the 2 up neatly. Interested in a better answer too.

Yea i tried to think of one that can do both nephrotic and increase salt retention.. but i couldn't think of any

EDIT. NVM it's just bad wording that confused me.. primary retention = overfill

 

[Myxedema]

can someone explain to me what this means?

The pathogenetic mechanism(s) of edema formation in nephrotic syndrome is:
Low oncotic pressure causing secondary renal salt retention. AND
Primary renal retention of salt.

What exactly does primary renal salt retention mean here in terms of causing nephrotic syndrome.. ?

Loss of albumin from the kidneys --> Hypoalbuminemia --> Decreased plasma oncotic pressure. Now, after this step, there are two main mechanisms for edema formation:

- Due to Starling forces, fluid will escape into interstitium --> Edema
- Decreased plasma oncotic pressure --> Decreased intravascular volume --> Activation of renin-angiotensin-aldosterone system; inactivation of cardiac natriuretic factors --> Salt and water retention --> Edema

These two mechanisms go hand in hand and can create massive generalized edema (termed anasarca).

 

[Ian]

Thanks Myxedema. I failed to consider the physiologic response to the loss of intravascular volume to the interstitium.