Nephrotic Syndrome I Flashcards
What are the features of nephrotic syndrome?
- Edema
- Proteinuria
- Hypoalbuminemia
- Hyperlipidemia
- Non-inflammatory
- Inactive urinary sediment (dysmorphic rbcs and rbc casts)
- Normal or mildly elevated creatinine
What is the key cell involved in nephrotic syndrome?
Visceral epithelial cell (podocyte)
What are some of the characteristics present in patients who present with chronic Glomerulonephritis?
- Hypertension
- Renal insufficiency
- Proteinuria (often over 3g/24hr)
- Smooth shrunken kidneys on ultrasound
What do patients with renal failure due glomerulonephritis referred to as rapidly progressive generally have in their urine?
- Red blood cell casts due to large numbers of red cells clumping in the tubules.
- Proteinuria but usually less than 3g/24hr
- BP is usually normal
What is one of the major causes of Rapidly progressive glomerulonephritis?
Autoimmune Vasculitis and patients will have features in other organs especially the skin
What are casts?
Cylindrical formations of cells or proteinaceous material.
What are the most common casts?
Hyaline casts
How are hyaline casts formed?
Form via precipitation of Tamm-Horsfall mucoprotein which is secreted by the renal tubule cells and sometimes contain albumin in conditions of proteinuria.
*A few Hyaline casts are normal
What are the second most common types of casts?
Granular type
What are granular casts?
Formed from aggregates of plasma proteins (albumin or immunoglobulin light chains) or the breakdown of cellular casts
How can granular casts differ in appearance?
Granular casts composed of fine granules are usually grey or pale yellow, granular casts composed of coarse grnules are darker often black
Where are granular casts believed to be formed?
In the renal tubule
How are “Fatty casts believed to be formed?
By the breakdown of lipid-rich epithelial cells
What are “Fatty cast”?
Tan-yellow hyaline casts with fat globule inclusions (oval fat bodies)
What is formed with “Fatty casts” in cholesterol esters are present?
Maltese cross pattern seen underpolarized light.
What are “Fatty casts” indicative of?
Lipiduria of nephrotic syndrome
What are red blood cell casts indicative of?
Glomerular damage
What are white cell casts indicative of?
Inflammation due to pyelonephritis, interstitial nephritis, acute post-streptococcal glomerulonephritis or nephrotic syndrome if it is associated with an inflammatory condition
What are the Nephrotic syndrome related diseases without glomerular inflammation?
- Minimal Change Disease
- FSGS
- Membranous nephropathy
- Diabetic Nephropathy
- Amyloidosis
- Light Chain deposition disease
What are the Nephrotic syndrome diseases with glomerular Inflammatory involvement?
- IgA Nephropathy
- Acute post-streptococcal glomerulonephritis
- Anti-GBM disease
In early course of post-infectious glomerulonephritis in general and in post-streptococcal glomerulonephritis in particular where do the inmmune complexes tend to be deposited?
the immune complexes tend to be deposited in a subendothelial location early on
In the later course of post-infectious
glomerulonephritis in general and in post-streptococcal glomerulonephritis in particular where do the inmmune complexes tend to be deposited?
They tend to be deposited in subepithelial location later on.
Where are the immune complex deposits classically in lupus nephritis?
Subendothelial
What are the factors that predispose the Glomeruli to trapping immune complexes?
- High plasma flow rate through them
- High intraglomerular pressure
- High glomerular hydraulic conductivity
What syndrome do subeepithelial deposits tend to cause?
Nephrotic.
What syndrome do subendothelial and messangial deposits tend to cause?
Nephritic
What are the clinical features of nephrotic syndrome?
- 50mg/kg/day of 3.5g/day
- 40mg/hour/M2 in children
- Hypoalbuminemia
- Hypercholesterolemia
- Lipiduria
- Possible Xanthelasma (sub-Q lipid deposits)
What are the absolute contraindications for renal biopsies?
- Bleeding Diathesis
2. Uncontrolled hypertension
What are some relative contraindications for renal biopsies?
- Single Kidney
- High pressure hydronephrosis
- Adult polycystic kidney disease
What can cause possible death because of a kidney biopsy?
Unrecognized retroperitoneal bleeding.
What is the main site of size hindrance for larger molecules?
Lamina Densa and slit disphragm
What is the main site for charge hinderance?
The anionic charged Lamina rara interna and fenestrated capillary endothelium
What is the major hinderance to albumin being filtered into the urinary space?
Charge!!!!
What happens to the proteins that make it into the urinary space?
Majority are reabsorbed in the proximal tubule.
How do epithelial cells of the proximal tubule reabsorb proteins?
By endocytosis involving the MEGALIN and CUBULIN.
What kinds of protein aare seen in the urine in Tubular disease?
LMW proteins
What protein does urine dipstick measure?
Albumin.
What is the low detection limit for a urine dipstick?
300-500mg/day
What is the definition of microalbuminemia?
30-300mg perday
What are 3 of the primary management aspects of nephrotic syndrome management?
- Control of hypertension/Low salt
- Ace inhibitor ARB
- Corticosteroids
- Immunosuppresion
What disease is associated with Foot process effacement?
MCD
What disease is associated with “Spike and Dome” appearance?
Membranous Nephropathy
What disease is associated with subepithelial humps?
Post-infectious glomerulonephritis
What disease is associated with Basketweave appearance?
Alport syndrome
Wire loops =
Lupus Nephritis
Tram Tracks=
Membranoproliferative glomerulonephritis
What is the protein that covers the foot processes and endothelial cells of the glomerulus?
Sialoprotein
