Nephrotic Syndrome in Adults
Nephrotic syndrome is a condition caused by particular kidney diseases. These diseases cause leakage of proteins, the most important of which is albumin, from the blood stream into the urine. This results in reduced levels of albumin in the blood stream and swelling of the ankles and sometimes other parts of the body known as oedema as well as the increased level of albumin in the urine. Nephrotic syndrome in adults is rare (it effects approximately 1 person per 30,000 people per year) but it is an important type of kidney problem and there are many people with nephrotic syndrome seen in kidney outpatient clinics.
If patients with nephrotic syndrome develop end stage kidney failure, the best treatment is a kidney transplant if they are suitable to receive one. However sometimes the same disease can cause damage to the new kidney. The risk of this happening depends on the original disease and will be carefully considered and discussed prior to a transplant.
Living with nephrotic syndrome
Although nephrotic syndrome can be a serious condition most people respond well to treatment and can live essentially a normal life particular if the condition goes into remission. Depending on the cause patients may respond to treatment within a few days but may take several weeks or even months. Most people would be well enough to study, go to work and drive during in this period.
Nephrotic syndrome does not normally affect sexual activity and women can become pregnant and deliver healthy babies. However nephrotic syndrome can increase the risk of problems in pregnancy and patients should not attempt to become pregnant whilst taking certain medications. Any plan to try for a family should be discussed with a nephrologist who may also involve an obstetrician to advise.
In general most diseases causing nephrotic syndrome are not hereditary so they cannot be passed on to any children.
Monitoring people with nephrotic syndrome
All patients with nephrotic syndrome would usually be seen regularly in a hospital nephrology outpatient clinic where they would be monitored by blood and urine tests. Sometimes diseases causing nephrotic syndrome go into remission and appear to be cured. In other cases the disease doesn’t respond completely or relapses at a later point.
Patient’s whose disease is in remission may be given some dipsticks to test their urine if they think it is getting frothy or if their ankles are swollen. This is a good way to detect a relapse and if there are signs of a relapse patients should let their GP or nephrologist know without waiting until the next outpatient appointment.
Young adults who have previously been seen in children’s hospital outpatients may find the change to an adult outpatient clinic unsettling. There will be a different environment and a new renal team to get to know. Some hospitals have special arrangements to help people to adapt well to the new situation. Sometimes bringing a friend along to the appointment may help and the renal team will be open to honest discussion about any problems or difficulties.
Treatment of nephrotic syndrome
Treatment includes general measures to combat the symptoms and consequences of nephrotic syndrome and specific drugs for particular conditions. General measures include reducing salt intake and water (diuretic) tablets to reduce swelling. Blood thinning drugs may be used to reduce the risk of blood clots and cholesterol lowering tablets may also be prescribed. Tablets known as ‘ACE inhibitors’ or ‘ARBs’ to reduce kidney protein leak whatever its cause and also lower blood pressure.
For the diseases causing primary nephrotic syndrome specific treatment will usually include drugs that suppress the immune system. These include steroids such as prednisolone and other drugs such as tacrolimus and cyclophosphamide. These are powerful treatments which can have significant side effects but they are usually necessary to treat these potentially serious conditions. The nephrologist would carefully explain to the patient the exact treatment recommended and what effects might be expected.
In secondary nephrotic syndrome specific treatments are those which treat the other disease or condition causing the nephrotic syndrome. For example in diabetes treatment may include tablets or insulin to lower the blood sugar and other tablets to lower the blood pressure.
How is nephrotic syndrome diagnosed?
When people develop the symptoms described above doctors will perform particular tests to confirm the diagnosis. These tests include a urine test to look for high levels of albumin and a blood test to look for low levels of albumin and to measure kidney function (creatinine or eGFR). If these abnormalities are detected a general practitioner would usually then refer the person to a hospital kidney specialist (nephrologist).
The nephrologist may perform further blood tests for specific conditions (such as blood sugar levels for diabetes) but usually a kidney biopsy is required to find out which disease is causing the nephrotic syndrome.
A kidney biopsy consists of taking a tiny sample of kidney out to be examined under the microscope. The biopsy may be performed as ‘day case’ or sometimes an overnight or longer stay in hospital may be necessary. The patient is asked to lie on their front and then the kidneys are examined using an ultrasound machine to find the best place to do the biopsy. The area is then numbed with local anaesthetic and a special needle is used to take the sample. Patients are usually asked to lie flat on their back for a period of time afterwards. This is to try to reduce the risk of bleeding which can occur after the biopsy.
Effects and consequences of nephrotic syndrome
Usually the first thing people affected by nephrotic syndrome notice is swelling of the ankles or frothy urine caused by the increased protein content. In some cases the whole of the legs may become swollen and this may extend up to the abdomen and can sometimes affect the face. The swelling is caused by water retention and so body weight increases. Other symptoms some people notice include tiredness and breathlessness.
Nephrotic syndrome increases the risk of blood clots and certain types of infections. It also results in an elevated cholesterol level. The kidney disease which cause nephrotic syndrome sometimes cause gradual scarring of the glomeruli so that they can’t filter the blood properly and so the body’s waste products build up in the blood stream. Eventually these levels become dangerously high (end stage renal failure) and then a transplant or an artificial treatment known as dialysis is necessary.
Kidney diseases which cause nephrotic syndrome in adults
Nephrotic syndrome is sometimes divided into primary and secondary nephrotic syndrome. Primary nephrotic syndrome is caused by diseases which specifically effect the kidneys and the glomeruli in particular. These diseases include:
Minimal change disease
Focal segmental glomerulosclerosis (FSGS)
Membranoproliferative glomerulonephritis (MPGN)
In secondary nephrotic syndrome damage to kidney filters occurs a consequence of (‘secondary’ to) some other disease or condition originating outside the kidney. Causes of secondary nephrotic syndrome include:
Systemic lupus erythematosus (SLE)
The main job of the kidneys is to filter the blood to get rid of the waste products of the body into the urine. Each human kidney contains approximately 1 million microscopic filters called glomeruli. These consist of a ball of tiny blood vessels whose walls are designed to the filter the blood. Normally they let lots of water and small molecule waste products of the body through into the urine but very little larger proteins like albumin which are needed in the blood stream. Certain diseases which damage these glomeruli cause them to become leaky so that they let excessive quantities out from the blood and into the urine.