Glomerular Disease Flashcards
What is proteinuria?
Increase in the amount of protein in the urine
What is the UPC value for non-proteinuric?
Dogs=
What is the UPC value for borderline proteinuric?
Dogs = 0.2-0.5 Cats = 0.2-0.4
What is the UPC value for proteinuric?
Dogs = >0.5 Cats = >0.4
What are the physiological causes of proteinuria?
Strenuous exercise, seizures, fever, stress
What are the pre-renal causes of proteinuria?
Abnormal concentration of protein being presented to the kidneys
What are the renal causes of proteinuria?
Defective renal function or inflammation of the renal tissue (glomerular or tubular
What are the post-renal causes of proteinura?
Inflammation or infection in the ureter, bladder, urethra, or prostate
How is proteinuria first detected?
On a urine dipstick
Is the urine dipstick quantitative or qualitative for proteinuria?
Semi-quantitative (not terribly accurate but good for screening)
What can cause false positive results for protein on a urine dipstick?
Alkaline urine or contamination
What can cause false negative results for protein on a urine dipstick?
Acidic urine or bence-jones proteinuria
T/F: Hematuria and pyuria have inconsistent effect on urine albumin concentration
True
What proteins are detected with the urine dipstick?
Most sensitive to albumin
What are some ways to identify physiological causes of proteinuria?
History and clinical examination
What are some ways to identify pre-renal causes of proteinuria?
Hematology and biochemistry
What are some ways to identify post-renal causes of proteinuria?
History, clinical exam, urinalysis, imaging
What are some ways to identify renal or post-renal inflammatory causes of proteinuria?
- Examine urine sediment
- Perform urine culture and sensitivity
What are some conditions that can cause renal or post renal inflammation?
Hyperadrenocorticism or exogenous steroid administration
Does minor contamination usually create enough sediment to indicate post renal inflammation?
No
Why do we want to quantify proteinuria?
- Evaluate severity of renal lesions
- Help identify location
- Assess disease progression
- Assess response to treatment
What is the gold standard to quantify proteinuria?
24hr protein measurement
Why do we usually not use the gold standard to measure proteinuria?
Because it requires specialized equipment that most hospitals don’t have
What is usually used to quantify proteinuria?
Urine protein:creatinine ratio
What does UPC negate?
The effect of urine volume and concentration
Does UPC correlate well to 24hr urine protein excretion?
Yes
What should UPC be interpreted in conjunction with?
Urine sediment findings
What may renal proteinuria be caused by?
Defective renal function or inflammation of the renal parenchyma
How is pyelonephritis ruled out?
Ultrasound
What can help confirm acute tubular necrosis?
Casts in the urine sediment
What are the options for renal poteinuria if inflammation in excluded?
- Glomerular disease
- Tubular disease
- CKD
Why does glomerular disease lead to proteinuria?
Increased glomerular permeability allowing for greater protein leakage
At what UPC should amyloidosis be considered?
> 8
Why does tubular disease lead to proteinuria?
Decreased tubular protein reabsorption
What is the UPC ratio usually in dogs and cats with tubular disease?
Why does CKD lead to proteinuria?
Adaptive changes within the nephron
Hyperfiltration causing hypertension, glomerular protein loss, tubular dysfunction causing reduced uptake
When can CKD cause profound proteinuria (over what it usually does)?
When CKD is caused by a primary glomerular pathology (dos espeically)
What pathology tends to cause the most significant proteinuria?
Glomerular protein loss
Protein losing nephropathy (PLN)
What is glomerulonephritis?
A group of conditions where immune complexes are deposited in the glomeruli
Is glomerulonephritis more common in cats or dogs?
Dogs
What conditions cause glomerulonephritis by chronic antigenic stimulation?
Inflammation, infection, or neoplasia
T/F: Many cases of glomerulonephritis are idiopathic.
True- 50% of cases
What familial nephropathy of the basement membrane effects Samoyeds?
X-linked hereditary PLN
What breed of dog is effected by Alport syndrome?
English cocker spaniels
Type IV collagen disease
What breeds are effected by amyloid deposits in the glomeruli (amyloidosis)?
Shar-pei, beagle, abyssinian, siamese
What chemotherapy drugs can cause glomerulonephritis?
Tyrosine kinase inhibitors
What infectious disease can cause glomerulonephritis that is important to screen for with a proper history?
Lyme disease
What is an easy in clinic test to rule out several infetious causes of glomerulonephritis?
4dX test- Borrelia, dirofilaria, ehrlichia, leishmania
How do you screen for neoplastic causes of glomerulonephritis?
Thoracic radiographs or abdominal ultrasound
What is important to check for in glomerulonephritis patients?
Blood pressure and hypercoagulability
Which BP measuring technique is better for cats and small dogs?
Doppler
Which BP measuring technique is better for larger dogs?
Oscillometic
How many readings should be done in order to ensure a more accurate BP measurement?
At least 5
Why are glomerulonephritis patients hypercoagulable?
- Mild thrombocytosis with increased platelet adhesion and aggregation
- Loss of antithrombin
- Altered fibrinolysis
What is the risk of hypercoagulability?
Thomboemboli- often pulmonary and fatal
How do we directly measure hypercoagulability?
Thromboelastography
How do we indirectly measure hypercoagulability?
- Platelet numbers
- Decreased antithrombin
- Increased fibrin
- Increased d-dimers
What are early clinical signs of glomerulonephritis?
May have no abnormalities
Loss of body condition, lethargy, or anorexia
What are the later signs of glomerulonephritis?
aka Nephrotic syndrome
Abdominal and pleural effusion, subcutaneous pitting edema, acute onset blindness, thromboembolic disease
What are the end stage clinical signs of glomerulonephritis?
Uremic syndrome
When is a kidney biopsy indicated?
- Persistant subclinical proteinuria
- Immune-complex doposition or amyloidosos is suspected
When is a kidney biopsy contraindicated?
IRIS stage IV patients or coagulopathies
What is the importance of IFA assesment?
Able to look for GBM remodelling or hypercellularity and synechiae at BM
What part of the kidney should be biopsied?
Cortex only
What techniques can be performed in order to obtain a kidney biopsy?
- Trucut ultrasound guided
- Key-hole sx technique
- Laparosocopy
- Laparotomy
What are the findings in nephrotic syndrome?
Proteinuria, hypoalbuminemia, ascites/edema, hypercholesterolemia
Often have hypertension and hypercoagulability as well
When is immunosupressive therapy indicated for glomerulonephritis?
When biopsy confirms ICGN (confirmed diagnosis)
When is immunosuppresive therapy contraindicated?
Pancreatitis, bone marrow suppresion, diabetes mellitus
Can you do a trial of immunosuppressive therapy in glomerulonephritis patients with no confirmed diagnosis?
Yes when you cannot do a biopsy or there is absent pathological disease
Must get owner consent and inform them of potential adverse effects
What are the advantages/disadvantages of glucocorticoid therapy in glomerulonephritis?
Can be used for rapid onset but hace long term adverse effects
What are the advantages/disadvantages of mycophenolate therapy in glomerulonephritis?
First choice therapy, rapid onset and low rate of adverse reaction
may cause therapy
Can other immunosuppresive therapies be used?
Yes- cyclosporine, chlorambucil, azathioprine, cyclophosphamide
What therapies can be used to treat proteinuria?
ACE inhibitors, Angeiotensin Receptor Blockers, and renal diets
What should be monitored with ACE inhibitor therapy?
Creatinine levels
What percent increase of creatinine should ACEi be discontinued?
30%
What can renal diets do to help treat proteinuria?
Anti-inflammatory agents, increase quality of protein and decrease levels, restrict sodium
How do you treat hypercoagulable patients?
Low dose aspirin or clopidogrel
What should NOT be done in hypercoagulable patients?
Drain effusions or treat with diuretics UNLESS there is difficulty breathing
What does the prognosos of glomerulonephritis depend on?
Underlying cause, severity of dysfunction, response to therapy
T/F: Glomerulonephritis is usually a progressive condition.
True
