Nephrotic Syndrome PDF

# NEPHROTIC SYNDROME ## I. BASIC PRINCIPLES - Glomerular disorders characterized by proteinuria (> 3.5 g/day) resulting in: - Hypoalbuminemia - pitting edema - Hypogammaglobulinemia - increased risk of infection - Hypercoagulable state - due to loss of antithrombin III - Hyperlipide...

# NEPHROTIC SYNDROME ## I. BASIC PRINCIPLES - Glomerular disorders characterized by proteinuria (> 3.5 g/day) resulting in: - Hypoalbuminemia - pitting edema - Hypogammaglobulinemia - increased risk of infection - Hypercoagulable state - due to loss of antithrombin III - Hyperlipidemia and hypercholesterolemia - may result in fatty casts in urine ## II. MINIMAL CHANGE DISEASE (MCD) - Most common cause of nephrotic syndrome in children - Usually idiopathic: may be associated with Hodgkin lymphoma ## III. FOCAL SEGMENTAL GLOMERULOSCLEROSIS (FSGS) - Most common cause of nephrotic syndrome in Hispanics and African Americans - Usually idiopathic: may be associated with HIV, heroin use, and sickle cell disease - Focal (some glomeruli) and segmental (involving only part of the glomerulus) sclerosis on H&E stain - Effacement of foot processes on EM - No immune complex deposits; negative IF - Poor response to steroids; progresses to chronic renal failure ## IV. MEMBRANOUS NEPHROPATHY - Most common cause of nephrotic syndrome in Caucasian adults - Usually idiopathic: may be associated with hepatitis B or C, solid tumors, SLE, or drugs (e.g., NSAIDs and penicillamine) - Thick glomerular basement membrane on H&E - Due to immune complex deposition (granular IF); subepithelial deposits with 'spike and dome' appearance on EM - Poor response to steroids; progresses to chronic renal failure ## V. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS - Thick glomerular basement membrane on H&E, often with 'tram-track' appearance - Due to immune complex deposition (granular IF) - Divided into two types based on location of deposits: - Type I - subendothelial: associated with HBV and HCV - Type II (dense deposit disease)—intramembranous: associated with C3 nephritic factor (autoantibody that stabilizes C3 convertase, leading to overactivation of complement, inflammation, and low levels of circulating C3) - Poor response to steroids; progresses to chronic renal failure ## VI. DIABETES MELLITUS - High serum glucose leads to nonenzymatic glycosylation of the vascular basement membrane resulting in hyaline arteriolosclerosis - Glomerular efferent arteriole is more affected than the afferent arteriole, leading to high glomerular filtration pressure - Hyperfiltration injury leads to microalbuminuria - Eventually progresses to nephrotic syndrome - Characterized by sclerosis of the mesangium with formation of Kimmelstiel-Wilson nodules - ACE inhibitors slow progression of hyperfiltration-induced damage ## VII. SYSTEMIC AMYLOIDOSIS - Kidney is the most commonly involved organ in systemic amyloidosis - Amyloid deposits in the mesangium, resulting in nephrotic syndrome - Characterized by apple-green birefringence under polarized light after staining with Congo red