Have you been told by your doctor that you have IgA nephropathy?
If so this information is to help you understand more about your kidney problem. It tells you about IgA nephropathy, about its cause and its effects, about treatments you may be recommended, and about the likely effect on your kidney function in the future. Most nephrologists [physicians specialising in kidney problems] call this condition IgA nephropathy, but you may hear it called IgA Disease or Berger's Disease (after the man who first described it). These names all describe the same condition.
What is it?
IgA nephropathy is the commonest of a group of conditions which have the general name glomerulonephritis. Glomerulonephritis means inflammation of the kidneys which particularly affects the glomeruli, the microscopic filters, of the kidney. IgA nephropathy is given that name because an antibody called IgA is deposited in the glomeruli.
How is it diagnosed?
Although your doctor may have suspected you had IgA nephropathy because of your symptoms (more of this later), the diagnosis could only be proved when you had your renal biopsy. When the pathologist examined the biopsy IgA was found in the glomeruli. Because IgA nephropathy (like all forms of glomerulonephritis) affects both kidneys equally, a small biopsy from one kidney will provide the answer.
What is IgA?
IgA is an antibody, part of our natural defences against infection. We all have plenty of IgA in our blood and also in the inner lining of our intestine and airways where it works in our defence. If you have IgA nephropathy, a very small proportion of all the IgA in your body sticks in your kidneys and sets off inflammation which damages the kidneys. The rest of the IgA in your body works normally so you have normal resistance to infection. Despite a lot of research we do not know why the IgA deposits in the kidney, so we do not yet know the fundamental cause of IgA nephropathy.
What are the common symptoms of IgA nephropathy?
The commonest way that IgA nephropathy comes to medical attention is because of blood in the urine (haematuria). Typically there are episodes of visible blood in the urine and these most often coincide with a sore throat or respiratory infection. Less commonly they seem to be brought on by a bowel infection or even by exercise. The urine may go bright red but more likely it will be brown (like tea without milk) or if there is less blood it may just look a bit smoky. Blood clots are not usually passed. The haematuria is usually painless although occasionally there is discomfort in the kidneys while the haematuria is visible.
Between these episodes there will still be invisible (microscopic) haematuria, which can be found if the urine is tested with a special stick which detects blood (stick tests of the urine are frequently performed at a doctor's office, a surgery or hospital outpatient clinic). Some people never have visible haematuria. The problem may therefore only be discovered when a urine sample is checked at a routine medical examination, for example when seeing a doctor for the first time, when starting a new job or when seeking life insurance. Some other types of glomerulonephritis may produce the same symptoms, so the kidney biopsy is needed to make the diagnosis. (There are of course many reasons for haematuria other than glomerulonephritis and these will also be needed to be checked for).
As well as blood there may also be proteinuria (protein in the urine). Usually this will only be found on a 'stick' test, but just occasionally there will be so much loss of protein in the urine that fluid retention occurs (usually first spotted as ankle swelling). This is known as 'nephrotic syndrome' but it happens less often in IgA nephropathy than in many other forms of glomerulonephritis. High blood pressure (hypertension) often occurs as in many other kidney diseases.
Who is likely to get IgA nephropathy?
The condition is three times as common in males as females -but this difference is unexplained. It also seems to be more common in some parts of the world – especially Japan, Singapore and other countries in the Pacific Rim. It is more common in Southern Europe compared to Northern Europe. We do not know the reasons for these geographical differences.
It can be diagnosed at any age but most commonly in children and young adults who are likely to have the typical story of episodes of visible haematuria. Older people are less likely to have visible haematuria; they are more likely to have protein as well as blood in the urine at the time of diagnosis and to have hypertension and other evidence of more advanced kidney damage. We presume that these older people have in fact had IgA nephropathy for many years but because they never had visible haematuria or a routine urine test, it was not diagnosed until a much later stage.
What will happen to my kidneys if I have IgA nephropathy?
Although the function of the kidneys of many patients does not deteriorate, we now know that about a quarter of all people with IgA nephropathy will eventually develop impaired kidney function followed by kidney failure. This is usually a very gradual process and may take twenty years or more.
Can you tell in each individual case about the risk of kidney failure?
We can identify those patients who are already a good way along that path. If there is protein as well as blood in the urine, if the blood pressure is raised, if the blood creatinine level (which measures kidney function) is already raised - then eventual kidney failure is much more likely.
The other information comes from your kidney biopsy. If haematuria is the only clinical sign of the disease, the biopsy may show very little damage to the kidneys other than the deposits of IgA, and the risk of kidney failure is small. If there is already proteinuria and hypertension, scar damage to the kidney will be much greater in the biopsy specimen; this scarring of the kidneys makes eventual kidney failure more likely.
Although we can make a good general prediction for each individual of what may happen, we cannot be certain. That is why it is vital to keep an eye on all patients with IgA nephropathy. Even if the only sign is haematuria and the biopsy looks favourable, there is still a small long term risk of kidney failure. For that reason you will be kept under long term review by your kidney specialist.
Does IgA nephropathy ever get better?
Yes it can do. In some people even the invisible haematuria will slowly disappear leaving no clinical evidence of the disease. We know that the IgA can still be in the kidney and haematuria may come back although this is unlikely. So regular check-ups are still necessary.
What happens if I have repeated attacks of visible haematuria?
Do not worry. Many people with IgA nephropathy have quite a few attacks of visible haematuria. These gradually get less frequent and usually stop altogether after a few years - although of course the blood will still be found on stick testing. You might think that with each attack more damage would be done to the kidneys but in fact there is not a close link between the number of attacks of haematuria and the chance of developing kidney failure later on. Only occasionally an attack of haematuria will cause a sudden deterioration in kidney function, which usually goes back to normal in a week or two, but this is unusual.
Does IgA nephropathy run in families?
Very occasionally a family will have more than one member affected by IgA nephropathy, but this is very unusual. For the great majority of patients with IgA nephropathy only one person in the family is affected, so there is no need for the rest of the family to be checked.
Does IgA nephropathy affect any part of the body other than the kidneys?
No, it does not, but there is a condition called Henoch-Schönlein purpura (often shortened to HSP) which is related to IgA nephropathy. HSP gets its odd name from the two German doctors who originally described it over a hundred years ago. We now know that the kidney problem in HSP is very similar to IgA nephropathy; but patients with HSP also get a skin rash and may have aches and pains in their joints and attacks of abdominal pain. IgA is found in the skin as well as in the kidneys in HSP. The skin, joint and abdominal effects of HSP often go away in a few weeks or months, but the kidney problem can stay much longer, and may eventually cause kidney failure. HSP can occur at any age but is commonest in young children.
If I have IgA nephropathy should I change my lifestyle?
No, you should not.
Diet - there are no foods known to cause IgA nephropathy or to provoke attacks of visible haematuria. You should continue with normal healthy eating.
Alcohol - alcohol has no effect on kidney disease. You may continue to drink alcohol in moderation.
Exercise - if you are one of the few patients who notice that vigorous exercise produces visible haematuria it may be sensible to avoid the activities you know do this. Otherwise you can continue to enjoy all physical activities.
What treatment is available for IgA nephropathy?
There are several different treatments to consider.
- Treatment to remove IgA from the kidneys and prevent any more depositing there. This would seem to be the best way to treat IgA nephropathy. Unfortunately we still understand so little of the reasons for IgA sticking to the kidney filters that we cannot give any specific treatment of this sort. Research continues into this problem, but there is no sign of such a treatment being developed in the next few years.
- Treatment for the attacks of visible haematuria. When visible haematuria occurs for the first time it can be dramatic and frightening. There is no specific treatment. Although it may seem you are losing a lot of blood it only needs a relatively small amount to colour the urine, so it is very unusual to become anaemic from haematuria in IgA nephropathy. The haematuria will settle down on its own in a few days. If the attacks are started off by a sore throat or other airway infection, the infection should not be treated any differently because you have IgA nephropathy. If you have a bacterial sore throat you may need antibiotics, but many of these infections are caused by viruses and will get better on their own. For many years patients were given a small dose of penicillin every day to prevent attacks but this makes no difference to the kidney disease. If you have many attacks of haematuria due to tonsillitis you may be advised to have your tonsils out [an operation known as tonsillectomy]. In some parts of the world, for example Japan, tonsillectomy is often recommended but there is no certain proof that this will reduce the chance of kidney failure. So the decision is usually based on the amount of trouble your tonsils are giving you, rather than the fact that you have IgA nephropathy.
- Steroids and other treatments to suppress your immunity. Because there is something slightly wrong with the immune system which causes the IgA to stick in your kidneys in IgA nephropathy, a number of treatments which suppress your immune system have been tried. These include steroids (such as prednisolone), cyclophosphamide and azathioprine, and mycophenolate There is no evidence that these provide any long term help for most people with IgA nephropathy. The best evidence is for steroid treatment, but kidney specialists are not yet agreed about which patients with IgA nephropathy should be recommended to have steroids. In a small number of patients whose kidney function is deteriorating rapidly immunosuppressive treatment may be useful; but it has potential for considerable side-effects. Your kidney specialist will carefully discuss the pros and cons of this approach with you if it is thought it may help to preserve your kidney function. There is one exception. If you have a lot of protein in the urine (nephrotic syndrome) a course of steroids may help to reduce this rapidly, helping you to feel better and perhaps reducing the chance of kidney failure. This treatment is only appropriate for a few patients with IgA nephropathy.
- Fish Oil. Fish oil sounds an unlikely treatment for kidney disease. But fish oil has a number of small effects on your body systems which together seem to reduce the inflammation and scarring which cause the kidney failure. There is now quite a lot of evidence that fish oil reduces the chance of kidney failure when given to those whose kidneys have already deteriorated quite a lot; although not all nephrologists are convinced by the evidence There is no reason to consider this treatment if your IgA nephropathy is mild. You could get the same effect from eating oily fish but you would have to eat such vast amounts it would not be possible; so the fish oil is given in capsules. Cod liver oil tablets which you can buy at a chemist are not suitable; the fish oil capsules must be prescribed by your doctor. Fish oil may be a good treatment because it does not have all the potential risks associated with steroids and other immunosuppressive treatment. However it may slightly reduce the efficiency of your blood clotting system although this is not usually a practical problem. It does also give some people a fishy taste in their mouth and some tummy upset which means they cannot manage to take it.
- Blood Pressure. Raised blood pressure is particularly common in patients with IgA nephropathy and may develop quite early on when the kidney damage is very mild. It is vital to control the blood pressure with tablets for two reasons. Firstly, it is important for your general health; we know that you are more likely to have a heart attack or stroke at a younger age if you have high blood pressure, but if the blood pressure is controlled that risk is greatly reduced. Secondly, it is very important for your kidneys. Once your kidneys have been damaged they are sensitive to the effects of raised blood pressure and will deteriorate more rapidly. Treating raised blood pressure is the one thing which definitely helps delay kidney failure in IgA nephropathy. Keeping blood pressure normal with tablets is therefore the single most important way of reducing the risk of kidney failure from IgA nephropathy. In IgA nephropathy, like all chronic kidney problems it is important to control the blood pressure very well; you can expect that the blood pressure goal recommended for you will be lower than for many other people who have high blood pressure without kidney problems. There is a debate at present about the best blood pressure treatments to use. There is good evidence that a type of blood pressure reducing tablet known as 'ACE inhibitors' are the best choice for blood pressure treatment if you have IgA nephropathy. This is because ACE inhibitors reduce the amount of protein in the urine as well as lowering blood pressure, and this helps to protect the kidneys from further damage.
- Treatment for kidney failure. If you have IgA nephropathy your kidneys may eventually fail. This happens to about a quarter of all patients and usually occurs very gradually, often over twenty years or more. If your kidneys fail, you will require treatment to replace kidney function, just as will be the case with other causes of kidney failure. The various forms of dialysis may be offered to you according to your personal circumstances. For many patients the best treatment, if it can be achieved, will be a kidney transplant. The fact that it was IgA nephropathy that caused your kidney failure does not have any effect on dialysis treatment.
What will happen if I have a transplant? Will IgA nephropathy damage my new kidney?
We know that IgA may stick in the glomeruli of your new kidney if you have a transplant. The immunosuppressive treatment which you receive to stop you rejecting your kidney does not prevent this happening. But this is not as serious as you might think. Although IgA gets into the kidney it usually does not cause much in the way of inflammation or damage to the kidney. The recurrence of IgA nephropathy may eventually contribute to the failure of the transplant but this is nearly always a very slow process as it is in your original kidneys. Overall the chance of a successful kidney transplant is still very good indeed if your original kidney problem was IgA nephropathy.
How will the best treatment for IgA nephropathy be identified?
Because the best treatment is still not known for most patients with IgA nephropathy, there is continuing research. It is very important that new treatments are only introduced if there is good scientific evidence to support their use. The most common way used to assess new treatments is by 'randomised controlled trials' in which patients agree to receive either the best known treatment or in addition to receive the new treatment, in order to see if the new treatment is an improvement. There are always such trials going on in different parts of the world to study new treatments. Your kidney specialist may therefore ask if you are willing to take part in sucha trial. You will be given a full explanation of any such trial, and it will be your free choice whether you take part or not.
We hope this information has helped you to understand more about IgA nephropathy. If you have any more questions or concerns do not hesitate to ask the nephrologist [kidney specialist] who treats you.
Further information for IgA nephropathy patients and their families can be found at the following websites. The International IgA Nephropathy Network includes these links for the interest of visitors to this site, and does not necessarily endorse all their content. Users of the Internet should use their discretion and common sense when evaluating materials they find on the web.
NIH Fact Sheet on IgA Nephropathy
Australian Kidney Factsheet on IgA Nephropathy
Cardiff Fact Sheet
Finnish Support Group
Korean Support Group
Danish Support Group
Yahoo IgA Nephropathy Support Group
European IgA Nephropathy Consortium