15 Questions - Kidney Issues and Lupus

(March 2012) Lupus nephritis, or inflammation in kidneys caused by lupus, can make kidneys unable to properly remove waste from your blood or control the amount of fluids in your body. This month, Dr. Brad H. Rovin answered your questions about kidney issues and lupus.

1. I get a checkup every 3 months with my rheumatologist. He checks blood & urine.  What is he looking at for numbers that indicate the kidneys are involved?  I heard that there were no symptoms of kidney involvement.  Milbridge, ME

The rheumatologist is looking specifically for a blood test called the serum creatinine. This test measures kidney function and if it is elevated above normal levels or the patient's baseline level it could indicate kidney dysfunction from lupus nephritis. When the doctor sends a urine sample for examination he/she is looking for blood in the urine, protein in the urine, and under the microscope specific types of cells and other material that could indicate damage to the kidneys. Although kidney disease can occur silently there are some things that will alert the patient to the possible involvement of the kidneys. These include the development of swelling especially in the ankles and lower legs. It is possible to see blood in the urine although that is fairly unusual in lupus nephritis because the blood is often at a level only detectable under the microscope. Sometimes as patients lose protein in their urine the urine becomes foamy in the toilet. Another sign of kidney involvement would be the development of high blood pressure.

2. Besides having blood work done, what bodily signs would someone have if they are beginning kidney failure?  Brandon, FL

Please see the answer to question one.

3. I am at a level (class) 5. What does that mean? What type of scale is used to measure kidney involvement?  Dallas, TX

Lupus nephritis, the term used for kidney involvement in SLE, is classified according to kidney biopsy findings. The new classification system for lupus nephritis was developed a few years ago by the International Society of Nephrology and the Renal Pathology Society.  It is a modification of the previous World Health Organization (WHO) classification. There are 6 classes of lupus nephritis. Class I is almost never seen because it shows minimal changes and doesn't have any clinical signs. The Classes that come to clinical attention are Class III, IV and V.  Class III and class IV are called proliferative lupus nephritis and are very inflammatory and can develop renal insufficiency fairly quickly.  The difference between Class III and Class IV is the percent glomerular involvement. Class V Lupus nephritis is also called membranous lupus nephritis. In this particular Class the immune complexes are made in lupus deposit on the urine side of the glomerular basement membrane. The glomeruli are the filtering units of the kidney, and as blood is filtered to form the initial urine, it is filtered across the glomerular basement membrane. In Class V the immune complexes are on the urine side of the glomerular basement membrane and they make the basement membrane leaky for protein. Class V lupus nephritis is characterized by a large amount of protein in the urine. Unlike class III and IV there is not a lot of inflammation in the kidneys. Therefore Class V tends to be less aggressive, does not usually present with kidney failure or abnormal kidney function, but can progress to towards kidney insufficiency over a long time if not controlled.

4. Can kidney inflammation related to Lupus cause low back pain that might feel like a kidney infection?  Garland, TX

Generally speaking the type of inflammation in the kidneys with lupus nephritis is different than the inflammation of a kidney infection known as pyelonephritis. Therefore it is unusual to have pain with lupus nephritis. Also the kidneys do not reside in the low back but actually in the upper part of the back, right under the ribs. When there is kidney pain it is generally located higher in the back rather than in the low back

5. Since lupus caused my kidney failure, would it affect my transplanted kidney?  Chicago, IL

Lupus nephritis can recur in a transplant kidney. This is a fairly uncommon event (only 4-9% of cases), and that might be because transplant patients are on potent immunosuppression after they receive a kidney.  Even if lupus does recur in the transplant kidney, it usually does not result in loss of the transplant. (see also answer to question 7).

6. What type of damage can lupus do to my kidneys? Can it cause kidney failure? El Paso, TX

In lupus the body makes antibodies to its own proteins and these antibodies can combine with these protein targets to cause immune complex formation. In lupus nephritis these immune complexes deposit in the kidney and specifically in the filtering units of the kidney called the glomeruli. This is where blood comes in to be filtered and waste products are excreted in the urine. These immune complexes can deposit in various places in the glomeruli and cause different types of damage to the kidney. In severe lupus nephritis they cause inflammation of the glomeruli along with destruction of the capillaries in the glomeruli. In other types of lupus nephritis the immune complexes cause damage to the filtration surface of the glomeruli and cause them to leak protein and blood into the urine. The inflammation in the kidney, or leakage of large amounts of protein through the kidney, can cause damage to the kidney, and if left unchecked and untreated overtime can cause kidney failure requiring renal replacement therapy with dialysis or transplantation.

7. How effective are transplants for patients with advanced kidney damage from lupus?  What is the quality of life after a transplant?  Canton, SD

In large cohorts of patients who have had kidney transplants it appears that patients with lupus nephritis as a cause of renal failure do just about as well as patients with other causes of renal failure. Therefore we believe that transplants are very effective for patients who have reached end-stage kidney disease because of lupus nephritis. Additionally, and maybe because of the immunosuppression used for kidney transplantation, sometimes after the transplant patients with lupus do not flare. The quality of life after a kidney transplant is very normal. Patients need to take medications lifelong to prevent rejection of the kidney, but these medications are similar to what one would take for lupus in general. Many of our transplant patients return to their normal daily routines, including their jobs.

8. I know every case/individual is different and will have different recommendations but how important is it to watch your diet if your kidneys are spilling protein? Is a vegan/vegetarian diet recommended? I've been reading conflicting articles - some saying no protein if you are spilling protein and others saying to eat protein since we are spilling protein.   Also, how much water intake is too much for the kidneys to handle?   Brooklyn, NY

In general for patients with kidney disease who have protein in the urine we do recommend a small reduction in protein intake. The average American diet contains about 1-1.2 g of protein per kilogram of body weight per day. In patients with chronic kidney disease and protein in the urine (proteinuria), we recommend a reduction in protein intake to 0.7-0.8 g per kilogram of body weight. We recommend that our patients see a dietitian who specializes in kidney disease to go over nutritional choices and to help the patient understand the protein content of food, and how to reduce protein. We do recommend that patients consume high quality proteins, and this can also be discussed with the dietitian. A vegan/vegetarian diet is not specifically recommended. That said, if a patient is spilling a large amount of protein, we do liberalize the restriction to include an amount of protein equal to that excreted in 24-hours over 3 g per day.

In terms of fluid intake it is really difficult to give a specific number because that will depend on several factors including the patient's size, blood pressure, cardiac status, and especially level of kidney function. Fluid restrictions of 1.2-1.5 L per day are often applied to patients with heart failure or advanced kidney failure, especially if they are retaining a lot of fluid that shows up as swelling of the legs, abdomen, or other parts of the body.  In the absence of such extremes I generally recommend that the patients drink to their satisfaction of thirst, rather than forcing fluid intake or drastically reducing fluid intake.  In periods of hot weather where one may be losing fluid through sweat, oral fluid intake would need to be increased.  Importantly, not only does one need to restrict fluid but also watch salt intake if the patient has kidney disease or a lot of protein in the urine, as this will aid in controlling swelling that may occur.

9. I have been diagnosed with Lupus for 4+ years.  2+ years ago anti ds-DNA antibodies were detected and the levels have continued to increase.   I have heard there is some correlation between anti ds-DNA count and eventual development of nephritis.  Is there such a link between anti-DNA counts and nephritis or am I mistaken?  Minneapolis, MN

There does appear to be an association of double-stranded DNA antibodies and patients having or developing lupus nephritis. This is not an absolute correlation. We see patients who have severe lupus nephritis and low levels or undetectable anti-double-stranded DNA antibodies, and we have patients who have high levels of these antibodies and no kidney disease. If you do have rising levels of anti-double-stranded DNA antibodies but your lupus is well-controlled, my suggestion is that your rheumatologist monitor for kidney disease very closely, perhaps twice to 3 times a year rather than simply screening once a year, if you have never had kidney involvement before.  If these antibody titers are rising in the face of symptoms of lupus it is possible that your doctor would need to increase your level of immunosuppression

10. What is the most effective treatment to reduce proteinuria? Are there any new treatments or combinations of treatments that have been successful in recent studies?  Las Vegas, NV

The treatment of proteinuria is fairly complex and there are 2 strategies. The first approach is nonspecific treatment of proteinuria that we apply to all patients with kidney disease where protein is lost in the urine. These measures include meticulous control of blood pressure, with target systolic blood pressures between 120-130 mmHg. The lower the systolic blood pressure, the better as long as this is tolerated.  In addition the type of blood pressure medications used can decrease proteinuria and actually protect the kidney. For blood pressure control we recommend inhibitors of the renin-angiotensin-aldosterone system, commonly known as angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARBs). These antihypertensive medications reduce proteinuria and prolong kidney function. Additionally, to control proteinuria we would like a no added salt diet, preferably a 2 g sodium diet. We also tend to reduce protein intake. For discussion of this see the response to question 8.

There are a number of treatments for lupus nephritis and of course one of the goals is the reduction or elimination of protein in the urine. The standard therapies do have a measure of success but complete remissions are still low. New biologic therapies are being tested in lupus nephritis and we will have the results of these in the coming months to years.  I believe there is a lot of promising therapies but they will not work in all patients with lupus nephritis and deciding which patients should be treated with which new therapy may become one of the more important questions in clinical trial work for lupus nephritis.

11. I was diagnosed with Lupus Nephritis about 8 years ago and was prescribed CellCept for treatment.  I stayed on the CellCept for 2 years and was taken off, but began to have kidney issues again 3 years later and was placed back on the medication.  It has been almost 2 years now.  How long is an individual expected to remain on the CellCept medication?  Is it safe to take for an extended period of time?  Detroit, MI

CellCept is a relatively well-tolerated immunosuppressive drug and has been used in the organ transplant field for many years, and these patients require the medication lifelong. Therefore we do believe that CellCept is safe to take over an extended period of time.  The question of how long an individual is expected to remain on CellCept is an important issue for which we do not have exact answers in lupus nephritis.  We believe that if a patient achieves complete remission of lupus nephritis that CellCept should be continued for at least one year beyond the complete remission and then the physician may taper this off slowly. If the patient achieves only a partial remission of their lupus nephritis, defined by protein in the urine, serum creatinine level, or findings on the urinalysis, then complete discontinuation of the medication may not be advisable and the duration of the therapy may be indefinite.

12. I get kidney infections a lot is the cause from lupus?  Gaston, SC

Lupus itself does not usually predispose to kidney infection. However the medications used to treat lupus and lupus nephritis suppress the immune system making the patient more susceptible to infections of any type and these could include urinary tract infections.

13. I have had lupus nephritis for 7 years now, was diagnosed as a teenager, and my main concern is having children.  I have already been told my prognosis is good as long as I am in remission when I decide to conceive, however my new concern is whether or not I will be able to physically bear children, as I'm afraid the stress of pregnancy and labor will further damage my kidneys?  Bellevue, WA

The issue of pregnancy in patients with lupus nephritis is complex and depends on your level of kidney function and the level of disease activity.  If lupus nephritis is in remission, and has been so for some time, several months to one year, then pregnancy is relatively safe if kidney function is normal.  Patients should be off most immunosuppression, but if immunosuppression is needed Azathioprine (Imuran®) would be one of the acceptable drugs. Some patients become pregnant and use steroids (prednisone).  Pregnancy in patients with kidney disease generally does not accelerate the kidney disease if kidney function is normal or near normal.  Patients with moderate renal insufficiency or active lupus nephritis at the time of pregnancy could have an accelerated renal functional decline.  We definitely do not recommend becoming pregnant with active lupus nephritis as the outcome for the mother and the child can be poor.  While pregnant one might have a flare of lupus nephritis that would have to be treated, patients must be closely monitored.  Overall we have worked with a large number of women with lupus nephritis who have been treated, achieved remission, and gone on to have successful pregnancies and healthy children.  If you are doing well and your prognosis is good as indicated in your question, and your rheumatologist or nephrologist thinks its okay to become pregnant, it certainly would be reasonable to do so.

14. What does remission of lupus nephritis exactly mean?  Does it mean that the kidneys are free of lupus?  Do the kidneys heal back to original function levels or is the damage permanent?  Holt, MI

Remission of lupus nephritis currently means that the clinical signs and symptoms of kidney involvement go away. That means that if the serum creatinine was increased it would go down to the patient's baseline or a normal level. The urinalysis would go back to be normal and would not show protein or blood, and the excretion of protein in the urine would resolve. Because we do not generally biopsy kidneys in patients who have undergone remission it is difficult to say that there is no remaining inflammation or that the kidney structure has gone back to the way it was before the lupus nephritis started.  It is likely however that after a flare of lupus nephritis there is some sustained damage to the kidney which may result in some scarring.  In most or many cases, this degree of permanent damage is small enough that it does not significantly impair kidney function.  One of the important research areas in lupus nephritis today is finding biomarkers that would indicate ongoing inflammation in patients that appear to have achieved full clinical remission so that appropriate treatment could be continued until those biomarkers normalized.

15. Any suggestions for controlling fluid retention and swelling in extremities?  Yorkville, WI

These recommendations have been outlined in the response to question 2 and question 8.