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For further information, see CMDT Part 22-18: Membranous Nephropathy
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Most common cause of primary nephrotic syndrome in adults
Caused by immune complex deposition in the subepithelial portion of glomerular capillary walls
Associated with
Underlying carcinomas
Infections, such as hepatitis B and C, endocarditis, syphilis
Autoimmune disease, such as systemic lupus erythematosus, mixed connective tissue disease, thyroiditis
Coagulopathy, eg, renal vein thrombosis, if nephrotic syndrome is present
Certain drugs, such as NSAIDs and captopril
Often presents in adults in the fifth and sixth decades
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May be asymptomatic
Edema
Frothy urine
Venous thrombosis, such as an unprovoked deep venous thrombosis, may be an initial sign
Secondary disease associated with symptoms or signs of an underlying infection, such as hepatitis B and C, endocarditis, and syphilis
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Underlying causes must be excluded prior to consideration of other treatment
Treatment of primary disease depends on the risk of progression of kidney disease
Conservative management includes therapy with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker if blood pressure is > 125/75 mm Hg to prevent or ameliorate proteinuria
Use of immunosuppressive agents should be limited to those with salvageable kidney function who are at highest risk for progression of kidney disease
Patients with nephrotic syndrome despite 6 months of conservative management and serum creatinine < 3.0 mg/dL (265 mcmol/L) may elect therapy with rituximab or with corticosteroids and cyclophosphamide for 6 months
Calcineurin inhibitors with or without corticosteroids may also be considered
Kidney transplantation