Lupus and Chronic Kidney Disease
Systemic lupus erythemotosus (SLE) or lupus is a chronic inflammatory disease. It causes the immune system to attack various systems of the body including the skin, heart, lungs, joints, nervous system, blood vessels and kidneys. It’s called systemic because it can affect the whole body.
An autoimmune disease like lupus prevents antibodies from working properly. With lupus, the antibodies aren’t able to tell the difference between harmful foreign substances and the body’s own healthy cells and tissue. As a result, the immune system attacks its own body parts, causing varying degrees of inflammation and organ damage.
Severe lupus may affect multiple organs including the kidneys, which are the most commonly involved. To date, the cause of lupus is unknown; however it has been linked to heredity and environmental factors. Lupus primarily targets women in their childbearing years. It also occurs more often in minorities. Around 90 percent of the people who get lupus are women, particularly African Americans, Latinos, Asians and Native Americans.
Other types of lupus
Although the broad term "lupus" usually refers to SLE, there are two milder forms of the disease.
Discoid (cutaneous) lupus primarily affects the skin, but may also involve the hair and mucous membranes. It is identified by a rash that appears on the face, neck, or scalp. This rash may last for days or years, and may also disappear and recur later.
Drug-induced lupus is triggered by certain prescribed medications, but usually goes away when the medicine is stopped. Two drugs most commonly connected with drug-induced lupus are hydralazine (used to treat high blood pressure or hypertension) and procainamide (used to treat irregular heart rhythms). Drug-induced lupus is more common in men; however, only about 4 percent of the people who take these drugs will develop lupus.
Lupus symptoms
No two lupus patients will have identical symptoms. However, there are common symptoms that include:
- joint aches
- low-grade fever
- arthritis
- fatigue
- facial "butterfly” rash
- unusual sensitivity to sunlight
- loss of appetite
- ulcers of the mouth and nose
- poor circulation in the fingers and toes with cold exposure (called Raynaud's phenomenon)
Lupus and the kidneys
The kidneys are especially vulnerable for people with lupus. Varying degrees of inflammation caused by the disease can result in lupus nephritis and even kidney failure.
Lupus nephritis is a term for kidney disease that occurs in SLE patients. With this disease, the tiny filters in the kidneys are damaged resulting in a loss of kidney function. This may lead to fluid retention with weight gain and swelling, called edema. Other than edema, there are very few signs or symptoms. Lupus nephritis doesn’t produce pain in the abdomen or back, or burning during urination.
It’s important to be aware that not all kidney problems in lupus patients are caused by lupus nephritis. Urinary tract infections occur frequently in lupus patients and require antibiotic treatment.
Similarly, medications used for treating lupus may produce signs of kidney disease that could be confused with lupus nephritis. For example, salicylate compounds, like aspirin, or non-steroidal anti-inflammatory drugs, like ibuprofen, are commonly used by lupus patients and can cause loss of kidney function or fluid retention. These problems usually fade when the medications are discontinued.
Treating lupus
Depending on the severity of disease and the specific organs involved, medications—both prescribed and over the counter—can be used to decrease swelling, lower blood pressure and decrease inflammation by suppressing the immune system.
Diet is also important and patients may need to limit protein, sodium and potassium; however, maintaining a well-balanced diet is very important. If any diet modifications are necessary, the physician will let the patient know and make a referral to a dietitian for individualized medical nutrition therapy.
Lifestyle changes should also be considered, which include staying out of the sun, wearing sunblock and avoiding stress. Getting enough sleep, along with regular exercise, helps prevent muscle weakness and fatigue. Support groups and counseling can help alleviate stress.
Additionally, people with lupus are advised to avoid smoking and drinking alcohol and asked to get regular medical checkups.
Despite appropriate treatment, some patients with lupus nephritis will develop kidney disease that could lead to renal failure. The condition can be treated with dialysis or a kidney transplant.
