Membranous Glomerulonephritis

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Contents 1 Etiology 2 Epidemiology 3 Pathology 4 Genetics 5 Clinical-manifestations 6 Laboratory 7 Diagnostic-procedures 8 Radiology 9 Complications 10 Management 11 More General Terms 12 Additional Terms 13 References

Etiology

• idiopathic (primary)
• secondary to systemic disease

• connective tissue disease

• systemic lupus erythematosus
• Sjogren's syndrome

• sarcoidosis
• malignancy (1.5% of cases)

• colon cancer
• lung cancer
• stomach cancer
• breast cancer
• lymphoma
• malignancies occur at 5 times the expected rate in patients with membranous glomerulonephritis

• hepatitis B
• quartan malaria
• sickle cell disease
• syphilis
• pharmacologic agents

• gold
• D-penicillamine
• captopril
• probenecid
• some NSAIDs

Epidemiology

• primary cause of idiopathic nephrotic syndrome in white adults (50%)
• mean age of onset is 35 years

Pathology

• deposition of cationic antigens in subepithelial space
• 'spike & dome' epithelial deposits of basement membrane material
• thickening of glomerular capillary wall
• immunofluorescence shows subepithelial granular deposits of IgG & C3

Genetics

• implicated genes: LRPAP1 ( p39RAP)

Clinical-manifestations

• slow progression with spontaneous remissions & exacerbations
• end-stage renal disease (20%)
• hypertension (40%)
• see nephrotic syndrome

Laboratory

• 24 hour urine: protein generally > 3.5 g (75%)
• creatinine clearance & glomerular filtration rates are generally near normal
• urinalysis

• microscopy: urine sediment generally unremarkable
• microscopic hematuria common

• serum complement levels are normal
• hepatitis serology
• antinuclear antibody

Diagnostic-procedures

• renal ultrasound
• renal biopsy
• colonoscopy

Radiology

• mammography
• chest X-ray

Complications

• renal vein thrombosis (25-50%) may cause acute renal failure
• systemic thromboembolism

Management

• high dose alternate day glucocorticoids
• combination of cytotoxic agent & glucocorticoids

• cyclosporine ( Sandimmune)
• mycophenolate ( Cellcept)
• tacrolimus [3]
• other cytotoxic agents

• cyclophosphamide ( Cytoxan)
• azathiaprine ( Imuran)
• chlorambucil ( Leukeran)

• ACE inhibitors may diminish the degree of proteinuria
• control hypertension
• treat underlying disorder

• lamivudine may benefit nephropathy in patients with hepatitis B [3]

• not all patients require treatment; without therapy

• 25% of patients will have complete remission
• 50% of patients will have partial remission
• 20% of patients will progress to end-stage renal disease

• optimal therapy not established
• screening for cancer (see etiology)

More General Terms

• glomerulonephritis (GN, nephritic syndrome)

Additional Terms

• nephrotic syndrome
• renal vein thrombosis
• systemic lupus erythematosus

References

1. Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 269
2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 608
3. Medical Knowledge Self Assessment Program (MKSAP) 11, 15, American College of Physicians, Philadelphia 1998, 2009
4. Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 1298, 1301
5. National Guideline Clearinghouse Membranous nephropathy: role of alkylating agents. Caring for Australasians with Renal Impairment ngc-guideline: [1]
   - Membranous nephropathy: role of steroids. Caring for Australasians with Renal Impairment ngc-guideline: [2]
   - Idiopathic membranous nephropathy: use of other therapies. Caring for Australasians with Renal Impairment ngc-guideline: [3]
   - Membranous nephropathy: role of cyclosporine therapy. Caring for Australasians with Renal Impairment ngc-guideline: [4]
   - Treatment of secondary membranous nephropathy. Caring for Australasians with Renal Impairment ngc-guideline: [5]

membranous glomerulonephritis; mesangiocapillary glomerulonephritis (membranous nephropathy)