Proteinuria

Question 1

What are the 3 layers that make up the filtration barrier of the glomerulus?

Answer 1

1. Fenestrated capillary endothelium
2. Glomerular basement membrane
3. Podocyte

Question 2

What is filtered through the glomerulus?

Answer 2

Anything bigger that 60-70,000 daltons is retained

A. Smaller solutes and water are freely filtered
B. Albumin is 69,000 daltons and is barely retained. A tiny amount may get through but is resorbed under NORMAL conditions.

Question 3

What is proteinuria an indicator of?

Answer 3

Glomerular permeability, tubular dysfunction, or disease in the body.

Question 4

Which diseases are associated with proteinuria?

Answer 4

1. Kidney disease
2. Hyperadrenocorticism
3. Neoplasia
4. Immune mediated diseases
5. Infectious diseases

Question 5

Why is proteinuria harmful?

Answer 5

1. Contributes to renal damage with inflammation and fribrosis over time
2. Thromboembolic events are possible with the loss of antithrombin III
3. Concurrent or consequential hypertension
4. Nephrotic syndrome (end stage proteinuria)

Question 6

What are the components of nephrotic syndrome?

Answer 6

Proteinuria, hypoalbuminemia, hypercholesterolemia, and edema

Proteinuria leads to a loss in albumin. Cholesterol tries to compensate for a loss of oncotic pressure be raising its levels. Cholesterol is ultimately unsuccessful and edema results.

Question 7

Which three things make up proteinuria?

Answer 7

Pre-renal, Renal, and Post-renal

Question 8

What are some examples of Pre-renal proteinuria?

Answer 8

Caused by an abundance of protein that overwhelms the resorptive capacity of the kidneys.

Examples include hemoglobin, myoglobin, etc.

Question 9

What are the two types of Renal proteinuria? Explain the two types

Answer 9

Pathologic: A defect in the glomerular filtration, tubular resorption, or interstitial damage. Most persistent cause of and contributes the highest levels of proteinuria

Functional: A mild/transient value that may be from heat, stress, seizure, venous congestion, fever, or exercise. It will resolve once the underlying cause is corrected

Question 10

Explain post-renal proteinuria?

Answer 10

Protein in the urine from a post kidney source. Examples include UTIs, inflammation, and hemorrhage. It is not persistent once the underlying condition is resolved.

Question 11

How do you determine if proteinuria is persistent?

Answer 11

Repeat the testing. Can do multiple samples 2 weeks apart.

Question 12

What does a positive urine dipstick (1+, 2+, 3+) tell you?

Answer 12

You need to confirm with a UPC to measure the degree of proteinuria. It is not a substitute. It can be falsely affected by many things like active sediment, prolonged contact time, or alkaline urine.

Question 13

Explain the UP/C

Answer 13

Should be measured to quantify the protein in the urine only if there is no evidence of urinary tract inflammation or hemorrhage. Do two urine samples collected over a week period.

Question 14

What about microalbuminuria?

Answer 14

Just know it exists and we don’t know the implications

Question 15

When should I monitor the UP/C?

Answer 15

When the patient is:

1. Non-azotemic with persistent/steady microalbuminuria
2. Non-azotemic with UPC less than 0.5

Goal is to identify renal proteinuria having ruled out post and pre renal causes

Question 16

When should diagnostics be run to identify the cause of proteinuria?

Answer 16

1. If borderline proteinuria on a UP/C is detected, reevaluate in 2-4 months
2. If proteinuria on a UP/C is repeatably (2 or more UP/Cs) >0.4 in a cat or >0.5 in a dog

Question 17

What are some of the therapeutic options for controlling proteinuria?

Answer 17

Ace inhibitors, Angiotensin II receptor blockers, and Omega 3 fatty acids

Question 18

What benefit do Ace inhibitors provide? Give an example of an ace inhibitor?

Answer 18

Decreases arterial resistance by dilating the efferent arteriole. Result is decreased glomerular pressure causing less protein to be pushed out.

Benazepril

Question 19

What are the effects of an Angiotensin II antagonist? Give an example of the medication

Answer 19

Binds to the angiotensin II receptor and blocks its activity (decreasing aldosterone release and subsequent Na/H20 retention). Add in with the ace inhibitor if needed to help decrease hypertension, but start with just ace inhibitor first.

Telmisartan

Question 20

What do Omega 3 fatty acids do?

Answer 20

Anti-inflammatory and reduce platelet activity

Question 21

Why do you need to prevent thromboembolic events associated with proteinuria?

Answer 21

Because of anti-thrombin III loss leads to predisposition of clots occurring

Question 22

How do you prevent thromboembolic events?

Answer 22

Clopidogrel: It acts on platelets

Question 23

If hypertension is unresolved after an ace inhibitor, what should you consider adding?

Answer 23

A. Telmisartin
B. Amlodipine: A vascular smooth muscle and cardiac muscle relaxant