Lupus and Lupus Kidney Disease - Types of Lupus Kidney Disease
These are the commonest types of kidney disease seen in people with Lupus who have a kidney biopsy:-
Type 1. Normal kidney . Some people with Lupus who have some protein in the urine can have a normal looking biopsy, and this is obviously the best finding, with a good long term outlook.
Type 2. "Mesangial glomerulonephritis". The kidney is not normal under the microscope, but the changes are not severe. Antibodies are found stuck in the filters of the kidney, but there is minimal damage and inflammation. Kidney function is usually normal in Type 2 kidney disease, and the long term outlook is good. However some cases can turn into the more serious Type 4 kidney disease.
Type 3. "Focal proliferative nephritis". In this type of glomerulonephritis, the membrane in the kidney filter is thickened, and the cells supporting the filters are inflamed and overgrown. However this change affects only part of each kidney filter, and indeed many filters may not be affected at all.
This type of kidney disease in Lupus is intermediate in severity. Some people do require treatment with steroids and more powerful immunosuppressants, other people can have more gentle drug treatment. A long period of follow up in clinic is required, as there is a risk of this disease becoming active in the future, when more powerful treatment may be required. Many people with focal proliferative nephritis have good kidney function for many years, but there is a risk of kidney failure. There may be water retention in the body due to nephrotic syndrome - click here for some more general information about nephrotic syndrome.
Type 4. "Diffuse proliferative nephritis". This is the most serious type of Lupus kidney disease. The membrane in the kidney filters is damaged and thickened, the cells supporting the membrane are overgrown, and their may be areas of dead tissue ('necrosis') or breakage of the membrane causing inflammation around each kidney filter, called 'crescents'. This type of kidney disease requires vigorous treatment, usually with powerful immunosuppressants.
Sometimes this kidney disease is seen in a Lupus crisis, when many parts of the body are affected by Lupus. Many people with diffuse proliferative nephritis respond well to treatment and the kidney function improves, but there is a significant risk of developing severe kidney failure, and needing long term dialysis (artificial kidney treatment). Sometimes dialysis is needed during a Lupus crisis, and the kidneys recover. Your specialist can advise in individual cases about the chances of recovering kidney function once dialysis has been started.
Type 5. "Membranous glomerulonephritis".This is a type of glomerulonephritis which affects the membranes in the kidney filters, but not the cells in the supporting structure of the filter. Membranous disease can cause heavy protein loss in the urine with nephrotic syndrome (water retention, click here for more details on Nephrotic Syndrome).
The Outlook in membranous is variable, and depends on details of each individual case - what the level of kidney function is, how much irreversible damage there is on the kidney biopsy, for example. Many people with membranous glomerulonephritis have good kidney function for years and do not develop kidney failure.
The treatment of membranous glomerulonephritis depends on the details of each individual case. Some people may require powerful drugs, in other cases minimal treatment may be best, concentrating on treatment of the blood pressure and cholesterol. Not everyone with membranous glomerulonephritis has Lupus.
"Interstitial nephritis" . Most cases of kidney disease in Lupus affect the filters of the kidney (glomerulonephritis). However, in some cases, damage is restricted to the 'interstitium', that is, the supporting tissue and drainage tubes lying in between the filters. (Nephritis is a medical term which means inflammation in the kidney.) Interstitial nephritis in Lupus can be a mild disease, or occasionally cause kidney failure. It can be associated with 'anti-cardiolipin antibodies'. If you have a glomerulonephritis, you may have some interstitial disease as well - it can all be rather confusing! There are several causes of interstitial nephritis apart from Lupus - click here for more details.
Infection. People with Lupus can also get infections in the kidneys, especially if they are taking drugs which reduce the activity of the bodys immune system (immunosuppressant drugs such as prednisolone, cyclophosphamide or azathioprine; go to the Treatment of Lupus section for more details). Most infections in the kidneys can be effectively treated with antibiotics.
The National Kidney Federation cannot accept responsibility for information provided. The above is for guidance only. Patients are advised to seek further information from their own doctor.