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33 Cards in this Set
- Front
- Back
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nephrotic syndrome
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Urine protein >3 grams in 24 hours
-Low albumin -edema spot protein to cr ratio instead of 24 hr collection is fine to do |
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Complications of Nephrotic Syndrome
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Hypoalbuminemia
Edema Hyperlipidemia Lipiduria Hypercoaguable state |
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Pathophysiology of Hypoalbuminemia in association with nephrotic syndrome
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a) urinary loss
b) increased tubular catabolism of albumin |
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Pathophysiology of Edema associated with nephrotic syndrome
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a) Decreased plasma oncotic pressure in systemic capillaries due to low albumin levels
b) Avid sodium and water retention by the kidney |
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Pathophysiology of Hyperlipidemia in assoc with nephrotic syndrome
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due to increased hepatic synthesis of lipoproteins, can be up to 400-600 cholesterol levels
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Pathophysiology of Lipiduria in assoc with nephrpotic syndrome
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Lipids are absorbed by tubular epithelial cells and appear in the urine as oval fat bodies. The urine may also contain free fat and fatty casts that resemble maltese crosses under polarized light
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fat under polarized light looks like
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maltese crosses
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Pathophysiology of Hypercoaguability in assoc with nephrotic syndrome
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Hypercoaguability-due to increased hepatic synthesis of coagulation factors and loss of regulatory factors (anti-thrombin III, protein C and S in the urine)
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Clinical consequences of nephrotic syndrome
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Predisposition to infection (especially gram positive) from low serum IgG levels
Increased risk of thromboembolism and renal vein thrombosis Possible predisposition to atherosclerotic vascular disease Urinary loss of hormone binding proteins (low total thyroxine and iron levels) |
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General Mgmt of Nephrotic Syndrome
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Salt restriction
Diuretics ACEI/ ARB Lipid lowering agent For patients on extended therapy with corticosteroids: monitor bone density and supplement with calcium carbonate and vitamin D |
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Histologic Lesions
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Minimal change disease
Focal and Segmental Glomerulosclerosis FSGS Collapsing Glomerulopathy MPGN Membranous Nephropathy Diabetic Glomerulosclerosis Amyloidosis Light Chain Deposition Disease |
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Minimal Change Disease
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Pathogenesis : primary podocyte disorder
**most common cause of nephrotic syndrome in children 90% of nephrotic syndrome in children less than 10 years of age presents as sudden onset of heavy proteinuria and edema Usually idiopathic- can be associated with NSAIDs and Hodgkin’s Disease Steroid sensitive nephrotic syndrome, vast maj of pts respond to steroid tx, children more than adults. Rarely progresses to RF |
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Histopathology of Minimal Change
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LM: Normal Glomeruli
IM: Negative EM: effacement of podocyte foot processes |
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Minimal Change Course and Tx
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>80% respond to corticosteroids or immunosuppressives
Relapse is common (>50%) Does not progress to renal failure |
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Focal and Segmental Glomerulosclerosis
Pathogenesis |
1)Unknown in idiopathic FSGS
2)In Familial FSGS the podocyte appears to be the primary site of injury 3)Secondary is associated with long standing nephron loss, sickle cell disease, reflux nephropathy, analgesics, IV heroin abuse and HIV (collapsing variant), obesity **Most common cause of nephrotic syndrome in African Americans |
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Histopath of FSGS
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LM: scarring in portions of some of the glomeruli
IF: IgM and C3 in scarred segments EM: effacement of foot processes No immune complex deposits |
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Presentation and Tx of FSGS
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Present with Nephrotic syndrome and early onset HTN and renal failure-may have microscopic hematuria
Idiopathic-40% respond to prolonged course of steroids Secondary FSGS-use ACEI or ARB-if possible treat underlying disease |
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Collapsing Glomerulopathy
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Most associated with HIV
Reported assoc with parvovirus and pamidronate Pt present with explosive onset of massive proteinuria, severe hypoalbuminemia, rapidly deteriorating renal function: bp may be normal More common in African Americans HIVAN-CD4 count is frequently low PX: Most progress to ESRD w/in 13 months of diagnosis ACEI may reduce proteinuria/slow the disease Can also be assoc with parvovirus BP can be normal in these pts |
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Histopath of Collapsing Glomerulopathy
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LM: FSGS w/ collapse of the glomerular tuft
IF: IgM and C3 in sclerotic lesions EM: Effacement of podocyte foot processes |
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Membranous Nephropathy
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Autoimmune disease in which antibodies are directed against a podocyte protein
M-type phospholipase A2 receptor (PLA2R) NEJM 7/2/09 Commonest cause of idiopathic nephrotic syndrome in caucasians Peak incidence is 4-6th decades M:F=2-3:1 Present with nephrotic syndrome or asymptomatic proteinuria, may have microscopic hematuria (55%) and early HTN (30%) associated with Lupus |
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Membranous Nephropathy Presentation
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May present w/ thromboembolic complications
May present with nephrotic syndrome or asymptomatic proteinuria Renal function and BP are often normal at presentation |
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Secondary Causes of Membranous Nephropathy
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Lupus nephritis
Hepatitis B/ malaria Gold, penicillamine, NSAIDs Occult Carcinoma (colon, lung, kidney, breast) De novo in renal transplants |
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Progression of Membranous Nephropathy
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rule of threes so to speak
40% spontaneous remission 30% progressive renal failure 30% persistent proteinuria with variable renal dysfunction Risk factors for progression: male gender, severe proteinuria(>10gm/24hr) HTN, azotemia, tubulointerstitial fibrosis and glomerulosclerosis |
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Histopath of Membranous Nephropathy
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LM: the capillary wall is interspersed with spikes of GBM extending between and around subepithelial deposits
IF: coarse granular glomerular capillary wall deposits of IgG EM: **subepithelial electron dense deposits separated by *spikes of basement membrane |
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Tx of Membranous Nephropathy
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ACEI, ARBs
Steroids/cytoxic agents |
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MPGN Variable Clinical Presentations
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microhematuria and non-nephrotic range proteinuria
Nephrotic syndrome Acute nephritic syndrome Crescentic RPGN Peak Incidence is 2nd-3rd decades |
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3 forms MPGN
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Type I-immune complex mediated (most common)
Type II- dense deposit disease Type III subepithelial and subendothelial deposits All have a double contoured GBM Factor H is a central regulator of the complement system: 1) acts as a component of the extracellular matrix 2) binds to cellular recepltors of the integrin type 3)interacts with many ligands such s heparin, C-protein may be involved in HUS |
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Histopath of MPGN
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LM: increased glomerular cellularity
IF: C3 and C1q deposits highlighting the lobular architecture of the glomerulus EM: large **subendothelial and mesangial deposits tram track |
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MPGN Type II
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Also known as **dense deposit disease
LM: accentuated lobulation and increased glomerular cellularity IF:capillary wall and mesangial deposits of C3 (exclusively) EM:Intramembranous and mesangial very dense deposits |
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MPGN type III
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Rare-immune complex mediated
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MPGN Clinical Characteristics
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HTN and decreased GFR may be present at diagnosis
> 80% w/ Type I have Hep C |
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MPGN Prognosis
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Slow progression to ESRD in Type I and II, more common in Type III
Spontaneous remission rarely occurs |
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only way to differentiate these diseases is by
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Bx of the kidney
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