Renal - Glomerular and Tubular Diseases Flashcards
Where are the 2 sites of possible renal protein loss?
The glomerulus and proximal renal tubule
What are the three layers of the glomerulus?
Capillary endothelium, glomerular basement membrane, and visceral epithelium (podocytes)
What size molecules and cells does the glomerulus exlude?
proteins > 67 kDa from the ultrafiltrate
What can unchecked proteinuria lead to?
Hypoalbuminemia, thromboembolism, and decreased nephron lifespan
At what age of onset do dogs get proteinuria?
Middle/old age. If the patient is younger, consider a familial glomerular disorder
Is proteinuria more common in dogs or cats?
dogs - it is rare in cats
What clinical signs are associated with mild gomerular disease?
azotemia
What clinical signs are associated with late proteinuria?
edema/effusion, thromboembolism, and organ damage
What will you find on CBC in a patient with proteinuria?
You may have anemia
What may you find on a chemistry in patients with proteinuria?
Hypoalbuminemia, +/- signs of decreased renal function (+/- azotemia, +/- hyperphosphatemia), and +/- metabolic acidosis
Will USG be affected by proteinuria?
Unlikely - the concentration ability is often intact
What may you find on urine sediment in a patient with proteinuria?
casts
What is the most common fist step to diagnosing proteinuria?
Urine dipstick
What is the most quantitative test for proteinuria?
UPC ratio - it will correlate with daily protein loss
What is the approach to proteinuric patients?
Confirm if the proteinuria is persistent or transient. Once persistency is confirmed then screen for underlying disease. Finally do a renal biopsy
What are the causes of transient proteinuria?
Fever, physical exertion, and seizure
What criteria does there need to be for proteinuria to be considered persistent?
It needs to be confirmed in 3-4 instances over 2-3 weeks
What screening tests can be done for underlying disease/cause of proteinuria?
PE (fundic exam!), CBC/Chem/UA, blood pressure, urine culture, imaging, vector-borne disease testing, and endocrine testing
What is the purpose of a renal biopsy in proteinuric patients?
To allow for definitive histopathological diagnosis
What are the indications for renal biopsies?
Lack of response to standard therapy, UPC >3.5, and if you are considdering immunosuppresion
What are the contra-indications for renal biopsies?
Underlying disease identified/treated, uncontrolled hypertension, coagulopathy, and end-stage CKD (stage 4)
What are the differentials for glomerular disease?
Membranoproliferative glomerulonephritis (MGPN), membranous nephropathy, proliferative glomerulonephritis, immunoglobulin A nephropathy, amyloidosis, glomerulosclerosis, other non-IC glomerulopathies, non-IC glomerulopathies, and tubular diseases
What accounts for 50% of cases of canine glomerular disease?
ICGN - immune-complex glomerulonephritis
What is ICGN more likely to respond to?
immunosuppression
How is glomerular disease managed?
Monitoring and treatment of underlying disorder, reduction and proteinuria, management of decreased renal function and other consequences, +/- immunosuppression
How can proteinuria be reduced nutritionally?
Decrease dietary protein (25-50%) and omega-3 fatty acid supplementation
How can proteinuria be reduced pharmaceutically?
Modulation of RAAS pathway with ace inhibitors or angiotensin receptor blockers
How is hypercoagulability managed in proteinuric patients?
The use of platelet inhibitors - Clopidogrel and Aspirin
What drug is used to manage hypertesion in proteinuric patients?
Amlodipine
Aside from hypercoagulability and hypertension, what other consequences of decreased renal function need to be managed?
Phosphorus intake, anemia, metabolic acidosis, and gastrointestinal manifestations
When is immunosuppression indicated in proteinuric patients?
If there is a lack of response to standard therapy
When should proteinuria be monitored?
1-2 weeks after a new therapy has been initiated or after initiating a new therapy
Since UPC varies day-to-day, how often should samples be collected during monitoring?
Samples over 2-4 days
What side effects are associated with ACEi and ARBs?
Excessive drop in blood pressure and GFR
What is nephrotic syndrome?
A syndrome associated with 4 concurrent findings
What are the 4 concurrent findings associated with nephrotic syndrome?
Proteinuria, hypoalbuminemia, hypercholesterolemia, and edema/effusion
What is the prognosis of proteinuric patients?
It varies - some cases can have long survival with appropriate control of disease
What conditions of proteinuria have a poorer prognosis?
Amyloidosis, Nephrotic syndrome, and concurrent azotemia
Fanconi’s syndrome is associated with an abnormal presence of certain metabolies in urine. What are the?
Glucose, amino acids, proteins, phosphate, and bicarbonate
What breed is the inherited form of Fanconi’s syndrome most common in?
Basenjis
What type of gene is the inherited form of Fanconi’s syndrome?
autosomal recessive
What can cause the acquired form of Fanconi’s syndrome?
Medications, labradors with copper hepatopathies, and chicken jerky treats
How is fanconi’s syndrome diagnosed?
Concurrent normoglycemia with glucosuria, proteinuria, amino aciduria, hypokalemia/phosphatemia, and metabolic acidosis
How is Fanconi’s syndrome treated?
Discontinuation of trigger (acquired) and supportive care
What supportive care can help in Fanconi’s syndrome patients?
Correction of electrolyte and acid/base abnormalities, IV/SQ fluid support
What is the prognosis of Fanconi’s syndrome?
Variable - inherited have a survival time of 5-6 mean survival after diagnosis and aquired can have spontaneous return to normal tubular function is possible
