Minimal change disease (MCD), also known as lipoid nephrosis or nil disease, among others, is a disease affecting the kidneys which causes nephrotic syndrome. MCD is responsible for 10–25% of nephrotic syndrome cases in adults. It is also the most common cause of nephrotic syndrome of unclear cause (idiopathic) in children. The swelling may be mild but patients can present with edema in the lower half of the body, periorbital edema, swelling in the scrotal/labial area and anasarca in more severe cases. Due to the disease process, patients with minimal change disease are also at risk of blood clots and infections.
Pathophysiology
Proteinuria
The cause and pathogenesis of minimal change disease is unclear and it is currently considered idiopathic. However, it does not appear to involve complement or immune complex deposition. Rather, an altered T cell-mediated immunologic response with abnormal secretion of lymphokines by T cells is thought to modify the glomerular basement membrane, specifically the podocytes, increasing permeability. An additional multi-center study published in 2024 confirmed the presence of nephrin autoantibodies in 44% of adults and 52% of children with minimal change disease. In this study, autoantibody level correlated with disease activity, with up to 90% of patients not receiving immunosuppressive therapy testing positive for nephrin antibodies. Microscopic amounts of blood are present in the urine of 10-30% adults with MCD. Other medications such as ACE inhibitors to reduce the amount of protein in the urine or statins to decrease high levels of cholesterol seen with nephrotic syndrome are generally unnecessary.