Glomerular Disease Flashcards
What are possible causes of proteinuria?
Physiological - strenuous exercise, seizures, fever, and stress
Pre-renal - abnormal concentrations of proteins been presented to the kidneys (MM)
Renal - defective renal function or inflammation of renal tissue
Post-renal - inflammation of the ureter, bladder, urethra, or prostate
How can you diagnose proteinuria?
Urine dipstick
- semi-quantitative
- more sensitive to albumin
- affected by urine concentration
What can cause a false positive for proteinuria on a urine dipstick?
Alkaline urine
Contamination
What can cause false negatives for proteinuria on a urine dipstick?
Acid urine Bence jones (multiple myeloma)
What diagnostics do you do to determine cause of proteinuria?
Physiological cause: history and clinical exam
pre-renal : hematology and biochem
Post-renal: history, exam, UA, imaging
Renal/post renal inflammation
- examine sediment for inflammatory cells
- perform culture and sensitivity
- hyperadrenocortisim or exogenous steroids
Why do you want to quantify proteinuria?
Evaluate severity of renal lesions
Potential to help guess location
Assess disease progression
Assess response to treatment
What methods can you use to quantify proteinuria ?
24hr urine protein measurement (Gold standard)
Urine protein:creatinine ratio (UPC)
-negates effect of urine volume and concentration
What are the causes of renal proteinuria ?
Defective renal function
- > glomerular pathology
- > tubular pathology
Inflammation of renal parenchyma
- > pyelonephritis
- > active tubular necrosis
If your UPC ratio >2.0, what do you expect as the cause?
Glomerular disease
If UPC ratio > 8, what do you expect the cause to be?
Amyloidosis
If UPC ratio is <2.0 what do you expect the cause of proteinuria to be ?
Tubular disease
T/F: chronic kidney disease can result in a proteinuria?
True
-due to adaptive changes in the nephron (hyper-filtration of remaining nephrons, glomerular protein loss, tubular dysfunction)
T/F: chronic kidney disease can be caused by a primary glomerular pathology
True
Causes significant proteinuria
What is the term used for the condition casing severe proteinuria due to primary glomerular disease?
Protein losing nephropathy
What is glomerulonephritis ?
Group of conditions where immune-complexes are deposited in the glomeruli
What are causes of glomerulonephritis ??
Chronic antigen stimulation (immune mediated, infectious, neoplastic)
Familial nephropathy basement membrane -> xlinked PLN of samoyeds or cocker spaniels
Immune complex glomerulonephritis
Non-immune complex GN
Amyloid deposits -> sharpei, beagle, Abyssinian, and Siamese
Case of glomerulonephritis, how do you diagnose cause?
Consider history/signalment
Travel history/infectious disease
Drugs (TKI)
Clinical exam and systolic BP
MDB
- CBC and biochem
- UA, culture/sens, UPC
Radiographs/US for neoplasia
You want to determine blood pressure in your patient with glomerulonephritis. How can you do this?
Look for end-organ damage (kidney, brain, eyes, and heart)
Indirect
- oscillometric
- Doppler
Remember white coat effect —> do an average of 5 readings
What causes hyperocagulabilty seen with glomerulonephritis?
Thrombocytosis
Increased platelet adhesion and aggregation
Loss of antithrombin
Altered fibrinolysis
Relative increase in large clotting factors
How can you measure hypercoagulablility?
Can measure D dimers (degredation products of fibrin)
Thromboelastography
- number of platelets
- decreased antithrombin
- increased fibrin
- increased d dimers
Clinical signs of glomerulonephritis ?
Early
- may have no clinical abnormalities
- loss of body condition
- lethargy, anorexia
Late (loss of protein and edema)
- abdominal and pleural effusion
- subcutaneous pitting edema
- acute onset of blindness
- thromboembolic disease
Very late
-uremic syndrome
When would you do a kidney biopsy?
Persistent subclinical proteinuria detected
Immune-complex glomerulonephritis or amyloidosis is suspected
CONTRAINDICATED in IRIS stave IV disease or coagulopathies
What is nephrotic syndrome?
Group of findings that include:
Proteinuria
Hypoalbuminemia
Ascities/edema
Hypercholesterolemia
Often have systemic hypertension and hypercoagulability
What is the treatment for glomerulonephritis ?
Immunosuppressive therapy
-provided proteinuria has been confirmed to be glomerular in origin
-provided a biopsy confirms ICGN (unless contraindicated -
> IRIS stage IV or other mitigating factors)
When is immunosuppressive therapy for glomerulonephritis contraindicated ?
Pancreatitis
Bone marrow suppression
Diabetes mellitus
What is the first choice immunosuppressive therapy for glomerulonephritis ?
Mycophenolate mofetil -> inhibit DNA
Glucocorticoids -> as additional therapy
Alternatives ->cyclosporine, chlorambucil, azathioprine, cyclophosphamide
How can you treat hypertension associated with glomerulonephritis ?
ACEi
ARB - aldosterone receptor blocker (telmisartan)
Calcium channel blocker (amlodipine)
How can you treat proteinuria associated with PLN?
ACEi
- > reduced intraglomerular BP
- > contraindicated in IRIS stage IV
- > monitor CREA
ARB
-> more complete blockade
Renal diets
- > supplemented with EPA and DHA (omega 3 fatty acids)
- > high quality protein and moderately restricted
- Na restricted
How do ACEi decrease proteinuria?
Decrease efferent arterial resistance —> decrease pressure
Reduce loss of glomerular heparin sulfate (protein in BM of glomerulus)
Decrease size of glomerular endothelial pore
Improve lipoprotein metabolism
Slow mesangial growth and proliferation
Inhibit bradykinin degradation
What can you use to treat the hypercoagulability associated with PLN?
Aspirin (low dose)
Clopidogrel
Manage uremia
