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

From the Guidelines

Minimal change disease (MCD) is a kidney disorder characterized by significant protein loss in urine (nephrotic syndrome) with normal-appearing glomeruli under light microscopy but foot process effacement visible on electron microscopy. It's the most common cause of nephrotic syndrome in children but can occur at any age. The first-line treatment for MCD is corticosteroids, with approximately 95% of children achieving urinary remission of proteinuria within 4 weeks and complete remission after an 8-week course of prednisone, as reported in the study published in Kidney International 1. Key characteristics of MCD include:

• Significant protein loss in urine
• Normal-appearing glomeruli under light microscopy
• Foot process effacement visible on electron microscopy
• Excellent response to corticosteroid therapy, with most patients achieving remission within 8 weeks. Treatment typically begins with oral prednisone, and the dose may vary depending on the patient's age and weight, with children receiving higher doses on a per kilogram basis compared to adults, as noted in the study 1. For steroid-resistant or frequently relapsing cases, alternative immunosuppressive therapies may be considered. Supportive care is also crucial in managing the disease and its complications, including the use of diuretics, ACE inhibitors, and statins. The disease is thought to result from T-cell dysfunction leading to podocyte injury and altered glomerular basement membrane permeability. While most children experience complete remission, adults may have a more complicated course with more frequent relapses requiring longer immunosuppressive therapy, highlighting the importance of individualized treatment approaches based on the patient's response and disease course.

From the Research

Definition and Characteristics of Minimal Change Disease

• Minimal Change Disease (MCD) is a major cause of nephrotic syndrome (NS) in children and a minority of adults 2, 3.
• MCD is characterized by intense proteinuria leading to edema and intravascular volume depletion 3.
• The pathologic hallmark of disease is absence of visible alterations by light microscopy and effacement of foot processes by electron microscopy 3.

Prevalence and Demographics

• In adults, MCD accounts for approximately 10-15% of patients with idiopathic NS 4, 3.
• MCD reaches a much higher percentage at younger ages, up to 70%-90% in children >1 year of age 3.

Treatment and Management

• The mainstay of therapy is prednisone, but steroid-sensitive forms frequently relapse 3.
• Steroid minimization strategies may decrease adverse effects in the treatment of MCD 5.
• Recent therapeutic advances, such as the use of anti-CD20 antibodies (e.g. rituximab), have provided long-term remission off-therapy and suggest new hypotheses for disease pathogenesis 2, 4, 3.
• Tacrolimus monotherapy can be an effective alternative treatment for patients wishing to avoid steroid therapy for MCD 6.

Relapse and Outcome

• MCD has a high relapse rate (50-75%), and repeated exposure to glucocorticoids is often required 5.
• Forms of MCD that respond to steroids usually do not lead to chronic renal damage, whereas forms that are unresponsive to steroids may subsequently reveal themselves as FSGS 3.
• The outcome is variable, but a substantial number of patients require long-term immunosuppression, with significant morbidity because of side effects 3.