What is minimal change disease (MCD), also known as nil disease or lipoid nephrosis?

From the Guidelines

Minimal change disease should be treated with corticosteroids as the first-line treatment, with approximately 95% of children achieving urinary remission of proteinuria within 4 weeks and complete remission after an 8-week course of prednisone. The treatment approach for minimal change disease (MCD) typically involves oral prednisone at a dose of 1 mg/kg/day (maximum 80 mg) for 4-6 weeks, followed by alternate-day therapy for another 4-6 weeks before slowly tapering 1. This regimen is based on the high response rate, with most patients (80-90%) responding within 8 weeks with complete remission of proteinuria.

Key Considerations

• Increasing the duration of corticosteroid therapy to a total of 12 weeks may improve the rate of sustained remission.
• Adults with MCD generally receive lower doses of prednisone on a per kilogram basis (1 mg/kg/day for 8 weeks).
• For steroid-resistant or frequently relapsing cases, second-line agents such as calcineurin inhibitors (e.g., cyclosporine) may be considered, as discussed in the workshop recommendations for cyclosporin in idiopathic glomerular disease associated with the nephrotic syndrome 1.

Treatment Approach

• Supportive care includes diuretics for edema, ACE inhibitors or ARBs to reduce proteinuria, and statins for hyperlipidemia.
• Regular monitoring of urine protein levels is essential to assess treatment response and detect relapses early.

Disease Characteristics

• MCD is characterized by significant protein loss in urine (nephrotic syndrome) with minimal visible changes to kidney tissue under light microscopy.
• It is the most common cause of nephrotic syndrome in children but can occur at any age.
• The disease results from podocyte foot process effacement caused by circulating factors, possibly produced by dysregulated T-cells, that alter the glomerular filtration barrier.

From the Research

Definition and Characteristics of Minimal Change Disease

• Minimal change disease (MCD) is a major cause of idiopathic nephrotic syndrome (NS), characterized by intense proteinuria leading to edema and intravascular volume depletion 2.
• In adults, it accounts for approximately 15% of patients with idiopathic NS, reaching a much higher percentage at younger ages, up to 70%-90% in children >1 year of age 2.
• The pathologic hallmark of disease is absence of visible alterations by light microscopy and effacement of foot processes by electron microscopy 2.

Treatment Options for Minimal Change Disease

• The mainstay of therapy is prednisone, but steroid-sensitive forms frequently relapse and this leads to a percentage of patients requiring second-line steroid-sparing immunosuppression 2.
• Tacrolimus monotherapy can be an effective alternative treatment for patients wishing to avoid steroid therapy for minimal change disease 3.
• Second-line treatments include rituximab (RTX), mycophenolate mofetil (MMF), calcineurin inhibitors (CNI), and cyclophosphamide (CTX) 4.
• Patients treated with RTX may be less likely to require a change of therapy and more likely to come off immunosuppressive drugs 4.

Outcomes and Relapse Rates

• Relapse is frequent in MCD in adults, with at least one relapse occurring in 73% of patients, and 28% being frequently relapsing 5.
• The median time to relapse after the second line was 66 versus 28 months in RTX versus non-RTX groups 4.
• A significant proportion of frequently relapsing patients became steroid dependent, and second-line agents were used for steroid dependence, steroid resistance, or frequent relapses 5.
• A short-term steroid regimen may represent an effective treatment option that ensures lower steroid exposure when treating adult steroid-sensitive MCD patients 6.