8/11/2016 AM Report – Nephrotic Syndrome

Definition of Nephrotic Syndrome:

Proteinuria > 3.5 g/24 hours (spot urine/creatinine >3.5 mg/mg)
Clinical evidence of edema
Lipiduria (maltese cross)

Nephrotic Range Proteinuria: > 3 g/24 hours without other findings

Primary Renal:
Minimal Change Disease
Focal Segmental Glomerulosclerosis
Membranous Nephropathy
Fibrillary/Immunotactoid Glomulonephritis

Secondary (Systemic) Disease:
Drug Induced

Minimal Change Disease:
Epidemiology: most common cause of NS in children < 10 years old; can be primary or secondary
Clinical Presentation: Sudden onset of edema Thrombotic episodes more common in adults AKI may be seen in 20% at time of presentation
Diagnostic Evaluation: Presence of nephrotic syndrome on labs Renal biopsy required for diagnosis
*Remember it appears essentially normal on light microscopy – need electron microscopy.

Focal Segmental Glomerulosclerosis (FSGS)
Epidemiology: most common cause of idiopathic NS in adults, predilection for blacks, can be primary, familial, or secondary (HIV)
Clinical Presentation:
Asymptomatic proteinuria to NS
Hypertension usually seen in 30-50%
Microscopic hematuria 25-75%
Decreased GFR at presentation 20-30%
Diagnostic Evaluation:
Serologic studies negative
Renal biopsy required for diagnosis

* Remember light microscopy shows scarring/sclerosis involving some (focal) glomeruli, which are affected only in a portion of the glomerular capillary bundle (segmental)

Membranous Nephropathy (MN)
Epidemiology: second leading cause of primary nephrotic syndrome; predilection for > 50 years old; can be primary (immune complex disease) or secondary (infection, autoimmune, cancer, drugs)
Clinical Presentation:
Abrupt onset of nephrotic syndrome
50% may have microscopic hematuria
70% have normal BP and GFR at presentation
Thombotic disease more common – especially with low albumin
Diagnostic Evaluation:
Renal biopsy required for diagnosis

* Immunofluorescence microscopy reveals diffuse, granular IgG deposition along capillary walls.

Treatment – General Approach:
ACEi/ARB à reduce glomerular pressure à reduce protein excretion (independent of BP effects)
BP Control:
Goal <130/80, reduces proteinuria
Dietary sodium restriction (<2g/day)
Diuretics – usually loop diuretics:
Diuretic resistance due to low albumin / proteinuria
Reduce edema slowly to avoid acute hypovolemia
Typically reverse with resolution of disease, dietary modification not helpful
Treat with stains

Funny Cartoon to help you remember the difference between Nephritic and Nephrotic Syndrome


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