Minimal change nephrotic syndrome; Nil disease; Minimal change disease; Idiopathic nephrotic syndrome of childhood
Minimal change disease is a kidney disorder. Each kidney is made of more than a million units called nephrons. Each nephron has a tuft of blood vessels called a glomerulus, which is surrounded by a Bowman’s Capsule.
Together, these structures filter blood and form urine.
Minimal change disease is one cause of nephrotic syndrome. It is named “minimal change” because the nephrons appear totally normal under a light microscope. The condition is only seen using an electron microscope, which reveals changes in the Bowman’s Capsule in the nephrons. Urine tests also show high protein levels.
Causes, incidence, and risk factors
Minimal change disease is the most common cause of nephrotic syndrome in children. It is also frequently seen 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 kidney failure.
There may be symptoms of nephrotic syndrome:
- swelling - especially around the eyes, feet and ankles, and in the abdomen
- foamy appearance of the urine
- weight gain (from fluid retention)
- poor appetite
Signs and tests
A physical examination would not reveal much except swelling. Blood tests and urinalysis reveal results typical of nephrotic syndrome, including high levels of urine protein, low blood albumin levels, and High cholesterol.
A kidney biopsy and examination of the tissue with an electron microscope would show the classic changes of minimal change disease. An immunofluorescence exam of biopsied kidney tissue is negative.
Swelling may be treated with diuretics, blood pressure control, and ACE inhibitor medicines. You may receive instructions on how much salt to allow in your diet.
Corticosteroids can cure minimal change disease in a vast majority of children. Some patients may require maintenance on steroids to sustain the remission.
A minority of children may relapse after they stop taking steroids. If that happens, they usually respond well to a repeat course of the steroids. Adults do not respond to steroids quite as well as children, but a majority still do find steroids effective. The frequency of relapses and steroid dependence may be greater in adults.
Frequent relapsers (more than 3 relapses) may need cytotoxic therapy. In most cases, this involves a course of cyclophosphamide. Other medicines that have been used include cyclosporine and chlorambucil.
Minimal change disease usually responds well to corticosteroids, usually within the first month. Relapse may occur but the patient may benefit from prolonged treatment with corticosteroids and immunosuppressive medications.
- 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.
There is no known prevention.
by Brenda A. Kuper, M.D.