What lab value determines proteinuria?
>300 mg per 24 hours is abnl
What is glomeular proteinuria?
leakage of plasma proteins through an altered glomerular filtration barrier
What is tubular proteinuria?
- Failure of reabsorption of lower molecular weight plasma protein
- never exceeds 2 grams per 24 hours
What is overflow proteinuria?
- Results from filtration of proteins, that are present in excess in the circulation
- suspected with multiple myeloma or other lymphoproliferative disorders
What is hypoalbuminemia?
What are the features of nephrotic syndrome?
- Peripheral edema
What is the primary factor of nephrotic syndrome?
proteinuria as a result of altered permeability of the glomerular filtration barrier for protein, namely GBM
What is the best way to determine nephrotic syndrome?
What causes HL in nephrotic syndrome?
- Increased hepatic lipoprotein synthesis
- Decreased oncotic pressure
- Increased urinary loss of regulatory proteins
What causes hypercoaguability in nephrotic syndrome?
- Increased urinary loss of antithrombin III
- altered levels of activity of proteins C and S, hyperfibrinoginemia, and platelet aggregability
What are clinical findings in nephrotic syndrome?
- Edema (starts peripheral, then mirrors CHF)
- Protein malnutrition
- Iron resistant microcytic hypochromic anemia
- Hypocalcemia (secondary to losses of urinary vit D binding)
- Increased susceptibility to infections due to losses and inability to maintain globulins
How do you tx proteinuria in nephrotic syndrome?
- ACEs and ARBs: give trial, monitor K, if not about 5.2, continue
- They are renal protective
How do you tx edema in nephrotic syndrome?
What are you cautious about?
- Salt restriction and loop diuretics
- Losing >1kg/day (2.2lbs) can cause prerenal azotemia causing person to have fluid restriction
How do you tx HL with nephrotic syndrome?
Aggressive statins, monitor LFTs
How do you tx hypercoaguability with nephrotic syndrome?
- Everyone needs to be on aspirin
- Everyone with thrombosis needs to be on Coumadin for at least 6mo
What does MCD show on light microscopy?
Glomerular size and architecture are nl
What is a poor prognosis with MCD?
presence of mesangial hypercellularity or spare deposits of C2 and IgM
Fusion of foot processes of visceral epithelial cells
What causes MCD?
- Idiopathic m/c,
- URI, immunizations, atopy, rifampin, NSAIDs, interferon
What do MCD lab studies show?
How do you tx MCD?
- Steroids: continue several weeks after proteinuria has resolved, at least 8 weeks (adults 20-24weeks)
- Alkylating agents (cyclophosphamide or chlorambucil) if continue to relapse
- Cyclosporine (last resort): usually lifetime use
Sclerosis with hyalinosis involving portions of fewer than 50% of glomeruli on tissue section
What does FSGS light microscopy show?
FSglomerulonephritis with entrapment of amorphous hyaline material, most commonly at areas of juxtamedullary glomeruli
What causes FSGS?
Unknown, most likely immunologic, >50% of nephrons must be loss
How do you tx FSGS?
- Renal transplant (recurrence 50%)
What are poor prognostic indicators of FSGS?
- abnl renal function
- heavy proteinuria
- African American
What is the leading cause of idiopathic nephrotic syndrome in adults?
What are secondary causes of Membranous nephropathy?
Hepatitis, syphilis, SLE, RA, sarcoidosis
Diffuse thickening of GBM without inflammation or proliferation
How do you tx Membranous nephropathy?
- Salt restriction, strict BP control, ACEi
- Transplantation successful
- Steroids not effective (no evidence of inflammation)
- Cyclophosphamide, clorambucil, and cyclosporine decrease amount of proteinuria but do NOT decresae time to ESRD
What is membranoproliferative glomerulonephritis?
Thickening of GBM with proliferative changes seen on light microscopy
Presence of subendothelial and mesangial deposits on electron microscopy
membranoproliferative glomerulonephritis Type 1
C3, IgG, IgM
membranoproliferative glomerulonephritis Type 1
What are clinical features of membranoproliferative glomerulonephritis Type 1?
Heavy proteinuria, active urinary sediment, nl or mildly impaired GFR
What conditions is membranoproliferative glomerulonephritis associated with?
Hepatitis, HIV, leukemia
How do you tx membranoproliferative glomerulonephritis type 1?
There is none known
Presence of electron dense deposits within GBM and other renal basement membranes
Type 2 membranoproliferative glomerulonephritis
What are clinical features of Type 2 membranoproliferative glomerulonephritis?
Proteinuria and nephrotic syndrome or hematuria
What is the most common autoantibody in Type 2 membranoproliferative glomerulonephritis?
How do you tx membranoproliferative glomerulonephritis Type 2?
How effective is transplantation with membranoproliferative glomerulonephritis?
Often has recurrence
Extracellular deposition of fibrous protein in site throughout the body
Glomeruli are filled with amorphous deposits that stain positive with congo red and show green birefringence
How do you tx amyloidosis?
- Alkylating agents (melphalan) and predinose to reduce proteinuria and improve renal function
- Melphalen and stem cell transplants can induce remission in 80% but have 45% mortality rate
How bad is the prognosis with primary amyloidosis?
It can lead to ESRD on avg of 2-3 years