Minimal Change Disease

Key Features

• Nephrotic range proteinuria

• In children, most common cause of proteinuric renal disease (80%)

• In adults, accounts for 20–25% of cases of primary nephrotic syndrome in those over age 40 years

• Can be idiopathic

• May also occur

  • Following viral upper respiratory infections (especially in children)

  • In association with neoplasms, such as Hodgkin disease

  • With drugs (lithium)

  • With hypersensitivity reactions (especially to nonsteroidal anti-inflammatory drugs and bee stings)

Clinical Findings

• Nephrotic syndrome

• Can cause AKI due to renal tubular damage and interstitial edema

Diagnosis

• No helpful serologic testing

• Biopsy should be considered for children

  • With nephrotic syndrome who exhibit unusual features (such as signs of other systemic illness)

  • Who are corticosteroid-resistant

  • Who relapse upon withdrawal of corticosteroid therapy

• Kidney biopsy

  • Light microscopy and immunofluorescence: no changes

  • Electron microscopy: characteristic effacement of podocyte foot processes

Treatment

• Prednisone, 60 mg/m²/day orally

  • Remission generally occurs with 4–8 weeks

  • Can take up to 16 weeks for adult patient to respond to treatment

  • Continue for several weeks after complete remission of proteinuria

  • Dosing tapers should be individualized

  • Many patients relapse and require repeated corticosteroid treatment

• Cyclophosphamide, a calcineurin inhibitor (tacrolimus, cyclosporine), or rituximab for patients with corticosteroid resistance or relapses

• Progression to end-stage kidney disease is rare

• Complications most often related to prolonged corticosteroid use