Nephrology Flashcards
What is the leading cause of CKD?
Diabetes(44%)
What are the three most common causes of CKD, in order of prevalence?
1) Diabetes
2) High blood pressure(hypertension)
3) Glomerulonephritis
Why does diabetes often result in CKD?
This condition is called diabetic nephropathy:having high blood glucose levels due to diabetes can damage the part of the kidneys that filters your blood. The damaged filter becomes ‘leaky’ and lets protein into your urine.
What is the main cause of nephrotic syndrome in adults?
diabetic glomerulosclerosis
Nephrotic syndrome presents as protein in the urine, low blood albumin levels, high blood lipids, and significant swelling.
In which diseases have proliferative podocytes been observed, and suspected to contribute to CKD?
1) FSGS(SJ Shankland, 2010)
2) Collapsed glomerular disease(Srivastava, 2006)
3) HIV related nephropathy(RK Medapalli, 2011)
What is FSGS?
disease in which scar tissue develops on the glomeruli. FSGS can be caused by a variety of conditions, and can present in three ways:
1) Idiopathic(no known cause)
2) Secondary( caused by toxins, infections, drugs)
3) Genetic
What is minimal change disease(MCD?)
disease affecting the kidneys which causes a nephrotic syndrome, most common in children.
So named because the cell pathology and subtle and can only be viewed under EM, not light microscope
The defining cellular phenotype is diffuse loss of podocyte foot processes(effacement), causing proteinuria
What is considered a “low” or pathological eGFR?
A eGFR below 60 for three months or more or a eGFR above 60 with kidney damage (marked by high levels of albumin in your urine) indicates chronic kidney disease
What is eGFR and how is it measured?
Glomerular filtration rate (GFR) is the best overall index of kidney function. Normal GFR varies according to age, sex, and body size, and declines with age. Serum creatinine is also factored into the equation to determine eGFR.
What clincial criteria are used to diagnose CKD?
1) GFR less than 60 ≥3 months
2) ACR ≥30 mg/L or other markers of kidney damage
How much blood do the kidneys filter?
about 180 liters of fluid are filtered by the kidneys every day. Thus, the entire plasma volume (about 3 liters) is filtered 60 times a day!
Filtration is primarily driven by hydraulic pressure (blood pressure) in the capillaries of the glomerulus.
What are some of the limitations of eGFR as a diagnostic?
- It is only an estimate of kidney function and a significant error is possible
- The 90% confidence intervals are quite wide, e.g. 90% of patients will have a true GFR within 30% of their estimated GFR and 98% have measured values within 50% of the estimated value.
- Identifying trends in eGFR is often more informative than one-off readings. i.e. a progressive fall in eGFR across serial measurements is more concerning than stable readings which don’t change over time.
What is BUN, and why is it used?
Blood urea nitrogen is a medical test that measures the amount of urea nitrogen found in blood. The liver produces urea in the urea cycle as a waste product of the digestion of protein. Normal human adult blood should contain 6 to 20 mg/dL of urea nitrogen.
Typically used in the differential diagnosis of acute vs chronic kidney disease
Make up 30-40% of the cells in the glomerulus; primary function is to remove trapped residues and aggregated protein from the basement membrane thus keeping the filter free of debris
mesangial cells
