Friday, July 23, 2010

When the plumbing fails....

Kidney involvement is considered one of the most disabling and potentially life threatening of the lupus complications.  Your kidneys are part of your renal system.  Your renal system also includes: two ureters, the bladder, and the urethra. As the primary organs of the renal system, your kidneys are responsible for:

  • maintaining the correct amount and type of body fluids
  • getting rid of waste products and toxic substances
  • regulating the hormones (chemical messengers) that help control blood pressure and blood volume

When inflammation occurs in the “nephrons” (or in non-doctor terms… the structures within the kidneys that filter the blood), is called glomerulonephritis or lupus nephritis.   Lupus nephritis is the term used when lupus triggers inflammation in your kidneys…rendering them incapable of properly removing waste from your blood and/or control the amount of fluids within your body. The risk is that abnormal levels of waste will build up in the blood and lead to edema (swelling).  If it is left untreated, lupus nephritis can lead to scarring and permanent damage to the kidneys and possibly end-stage renal disease (ESRD) (or in non-doctor terms…kidney failure). People with ESRD need regular filtering of their body’s waste done through dialysis or receive a kidney transplant so that at least one kidney is functioning properly.

It is important to note, that not all kidney problems in people with lupus are due to lupus nephritis.  Some other things affecting the kidneys and urinary tract.

  • Infections of the urinary tract, causing frequent urination or burning when urinating, are quite common.
  • Fluid retention or even loss of kidney function can be a side effect of non-steroidal anti-inflammatory drugs (NSAIDs) and medications such as aspirin.
  • Interstitial nephritis, which is inflammation of the connective tissue inside the glomerulus, can be a side effect of anti-inflammatory medications or antibiotics.
  • Thrombosis and vasculitis, two blood-related lupus symptoms, can damage the kidneys and may even cause kidney failure.
  • Lupus cystitis, which is inflammation of the lining of the bladder, may cause frequent urination and is associated with abdominal discomfort, including vomiting and weight loss.

Lupus nephritis most often develops within the first five years after the initial onset of lupus symptoms.  Typically, people between the ages of 20 and 40 are affected. It is estimated that as many as 40 percent of all people with lupus, and as many as two-thirds of all children with lupus, will develop kidney complications that require medical evaluation and treatment.   Unfortunately, there can be very few symptoms of active kidney disease which can result in significant damage to your kidneys before you are even diagnosed with lupus.  (Sudden leg swelling and high blood pressure were my first symptoms.  It took them about 4 weeks before we started checking my kidneys.  My mom has cardiovascular disease so it was lots of heart testing.  Thankfully, my heart is unscathed.  No signs of cardiovascular issues.  The “plumbing” there is perfect. J )

In the early stages of lupus nephritis, there are very few signs that anything is wrong. Often the first symptoms of lupus nephritis are weight gain and puffiness in your feet, ankles, legs, hands, and/or eyelids. This swelling often becomes worse throughout the day. Your urine may be foamy or frothy, or have a red color. Often the first signs of lupus nephritis show up in clinical laboratory tests on the urine. That is why testing your urine is so important.  (Pitting edema is not fun to have.  I have worn out many pairs of shoes because my feet went from size 8 to elephant size in a matter of hours…seriously…nearly tripling in size with swelling all the way past my knees.  My blood pressure would shoot up from 110/60 to 160/100 or higher.  That high causes headaches…and makes vasculitic headaches MUCH worse.)

Typically, nephrologists (kidney specialist) will use the following tests to diagnose lupus nephritis:  urinalysis -- usually over a 24-hour period; blood tests; and often, a kidney biopsy.  Because your body’s waste matter is processed by your kidneys, testing a sample of your urine can show any problems with the way your kidneys are functioning. The most common tests look for cell casts (fragments of cells normally found in the blood, or fragments of the tubules of the kidneys) and proteinuria (protein being spilled into your body because your kidneys are not filtering the waste properly).  (This is also something that diabetics watch out for as it could be a sign of ketoacidocis.  My dad was diabetic, and this was an issue that told us when his kidneys were being injured by his diabetes.)

Certain blood tests can provide information about kidney damage and how well your body is filtering waste. The creatinine blood test is usually ordered along with a blood urea nitrogen (BUN) test to assess kidney function. A combination of blood and urine creatinine levels may be used to calculate a creatinine clearance. This measures how effectively your kidneys are filtering small molecules like creatinine out of your blood. Serum creatinine measurements (along with your age, weight, and gender) are used to calculate the estimated glomerular filtration rate (EGFR), which is used as a screening test for evidence of kidney damage.

A kidney biopsy is done in a hospital. While you lie on your stomach your nephrologist will insert a very thin, long needle through the skin of your back and remove a tiny piece of tissue from one of your kidneys. The tissue will be examined under a microscope to determine how much inflammation or scarring is present.  (This procedure sucks.  It is uncomfortable and you will have blood in your urine.  You have to take it easy for at least 24 hours after the procedure.  No lifting for like a week…or you could cause bleeding issues. Don’t ask how I know.  >.< )

Fixing the plumbing…

Even though lupus nephritis is among the more serious complications of lupus, there are effective treatments. Prednisone and other corticosteroids are generally prescribed to stop the inflammation. Immunosuppressive drugs may also be used (with or in place of steroid treatments), such as cyclophosphamide (Cytoxan®), azathioprine (Imuran®), cyclosporin A, and mycophenolate mofetil (CellCept®). Medications developed for other illnesses are also being studied as treatments for lupus nephritis, including rituximab (Rituxan®), and eculizuimab (Soliris™).  (I am currently taking prednisone.  I just had a round of IV solumedrol …which is 1 gram of prednisone…my daily dose is 60mg…the massive dose was to counteract an episode.  My creatinine is still too elevated…1.4 is the highest normal level and I am at 2.0 right now.  The other labs are still in the safe zones but this one is still being difficult.  I am waiting to be put back on immunosuppressives and/or the chemotherapy.  It’s been many weeks since the shingles…apparently the virus antibodies are still circulating in my bloodstream as well which means that if they suppress me now the shingles will activate again.  So…we wait…the antibodies have to disappear before they put me back on the meds I need to keep the lupus in check.)

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