A disorder of the kidneys that affects the structures (glomeruli) which include small capillaries surrounded by membranes through which the blood is filtered to form urine.

Alternative Names

Minimal change nephrotic syndrome; Nil disease; Lipoid nephrosis; Idiopathic nephrotic syndrome of childhood

Causes, incidence, and risk factors

Minimal change disease is one cause of nephrotic syndrome . It is named because under a light microscope the glomeruli appear totally normal. Under an electron microscope characteristic changes in the glomeruli can be seen, including the fusion of a portion of the epithelial layer. Minimal change disease is most common in children but occasionally occurs in adults. The cause is unknown, but the disease may be preceded by viral infection, allergic reactions or recent immunizations. Minimal change disease does not reduce the amount of urine produced. It rarely progresses to renal failure .

Signs and tests

The examination is nonspecific except for

edema . Blood tests and urinalysis reveal results typical of the nephrotic syndrome including high levels of urine protein, low blood albumin levels and high cholesterol. A renal biopsy and examination under electron microscope shows classic changes of minimal change disease. An immunofluorescence examination of renal biopsy tissue is negative.

Treatment

The goal of treatment is eliminating the proteinuria (protein excretion in the urine). Corticosteroids are usually effective in curing minimal change disease. Other medications such as cyclophosphamide or chlorambucil may also be used if the disorder recurs repeatedly after discontinuing corticosteroids. Treatment of nephrotic syndrome symptoms may be needed. This usually involves angiotensin converting enzyme inhibitors (ACEI) and diuretics to control or improve urine protein loss and swelling. High-protein diets are of debatable value for symptoms of nephrotic syndrome. In many patients, reducing the amount of protein in diet produces a decrease in urine protein . In most cases, a moderate protein diet (1 gram of protein per kilogram of body weight per day) is usually recommended. Sodium (salt) may be restricted to help control edema ( swelling ). Vitamin D may need to be replaced if the nephrotic syndrome is chronic and unresponsive to therapy.

Expectations (prognosis)

Minimal change disease usually responds well to medical treatment, with response to corticosteroids usually within the first month. Relapse may occur but often responds to prolonged treatment with corticosteroids and immunosuppressive medications.

Complications

side effects of medications

nephrotic syndrome

Calling your health care provider

Call for an appointment with your health care provider if symptoms occur that are suggestive of minimal change disease.

If you have this disorder, call for an appointment with your health care provider if symptoms worsen or new symptoms develop, including side effects of medications used to treat the disorder.

Prevention

There is no known prevention.