Lupus is a short name for a disease called "lupus erythematosus." The word lupus means wolf in Latin. The skin rash that some patients get can form a butterfly pattern over the bridge of the nose, resembling the bite of a wolf. Lupus is called an "autoimmune" disease because the immune system, which usually protects the body from disease, turns against the body, causing harm to organs and tissues. There are two types of lupus. Systemic lupus erythematosus can harm your skin, joints, kidneys and brain and may be fatal. The other type, called "discoid" lupus erythematosus, affects only your skin. No one knows what causes the disease. Your family history and things in your environment such as infections, viruses, toxic chemicals or pollutants (car fumes, factory smoke) may play a role in causing the disease. Men and women of all ages and races get lupus. However, it is about 10 times more common in women than in men. About 500,000 Americans have lupus. Different people get different symptoms. These may include skin rashes, joint pain, hair loss, sun sensitivity, tiredness, weight loss, fever, swelling of lymph glands, chest pain and nerve involvement. About 90 percent of lupus patients will have some kidney damage, but only two to three percent actually develop kidney disease severe enough to require treatment. The kidney disease may be "silent" and not cause any symptoms. However, you may have dark urine, flank pain, high blood pressure, weight gain from extra fluid and swelling around your eyes and in your hands and feet. Lupus is treated with drugs that block your body's immune system. Some of these are prednisone, azathioprine, cyclophosphamide or cyclosporine.
Goodpasture Syndrome is an uncommon disease that affects both the kidneys and the lungs. If you have the disease, usually you will:
bleed from the lungs
cough up blood
have inflamed kidneys (glomerulonephritis).
Usually, symptoms will occur because your body is making antibodies that hurt the lining of your lungs and kidneys. It is not known why your antibodies begin to attack your own body. Usually they only do helpful things such as fight infections. This problem is most common in people between the ages of 15 and 35 or after age 55. It is not contagious and it is more common in men and Caucasians. Goodpasture Syndrome may cause life-threatening bleeding in the lungs, but does not usually cause long-term damage in that area. The harm done to your kidneys, however, can result in kidney failure. Early diagnosis and treatment are the best ways to prevent kidney damage. Your doctor will give you medicine that will fight the harmful antibodies. The doctor may suggest that you undergo a special blood filtering process (plasmapheresis) to remove harmful antibodies. Usually, your body will make the antibodies for a short time, anywhere from a few weeks to two years. Once this stops, you should not have any more problems with your lungs. However, your kidneys may have been harmed a little or a lot.
IgA nephropathy is a form of glomerular disease that results when immunoglobulin A (IgA) forms deposits in the glomeruli, where it creates inflammation. The most common symptom of IgA nephropathy is blood in the urine, but it is often a silent disease that may go undetected for many years. It appears to affect men more than women. Although IgA nephropathy is found in all age groups, young people rarely display signs of kidney failure because the disease usually takes several years to progress to the stage where it causes detectable complications. No treatment is recommended for early or mild cases of IgA nephropathy when the patient has normal blood pressure and less than 1 gram of protein in a 24-hour urine output. When proteinuria exceeds 1 gram/day, treatment is aimed at protecting kidney function by reducing proteinuria and controlling blood pressure. Blood pressure medicines—angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers (ARBs)—that block a hormone called angiotensin are most effective at achieving those two goals simultaneously.
Acute post-streptococcal glomerulonephritis (PSGN) can occur after an episode of strep throat or, in rare cases, impetigo (a skin infection). The Streptococcus bacteria do not attack the kidney directly, but an infection may stimulate the immune system to overproduce antibodies, which are circulated in the blood and finally deposited in the glomeruli, causing damage. PSGN can bring on sudden symptoms of swelling (edema), reduced urine output (oliguria), and blood in the urine (hematuria). Tests will show large amounts of protein in the urine and elevated levels of creatinine and urea nitrogen in the blood, thus indicating reduced kidney function. High blood pressure frequently accompanies reduced kidney function in this disease. PSGN is most common in children between the ages of 3 and 7, although it can strike at any age, and it most often affects boys. It lasts only a brief time and usually allows the kidneys to recover. In a few cases, however, kidney damage may be permanent, requiring dialysis or transplantation to replace renal function.
Bacterial endocarditis, infection of the tissues inside the heart, is also associated with subsequent glomerular disease. Researchers are not sure whether the renal lesions that form after a heart infection are caused entirely by the immune response or whether some other disease mechanism contributes to kidney damage. Treating the heart infection is the most effective way of minimizing kidney damage. Endocarditis sometimes produces chronic kidney disease (CKD).
HIV, the virus that leads to AIDS, can also cause glomerular disease. Between 5 and 10 percent of people with HIV experience kidney failure, even before developing full-blown AIDS. HIV-associated nephropathy usually begins with heavy proteinuria and progresses rapidly (within a year of detection) to total kidney failure. Researchers are looking for therapies that can slow down or reverse this rapid deterioration of renal function, but some possible solutions involving immunosuppression are risky because of the patients’ already compromised immune system.
Focal segmental glomerulosclerosis (FSGS) describes scarring in scattered regions of the kidney, typically limited to one part of the glomerulus and to a minority of glomeruli in the affected region. FSGS may result from a systemic disorder or it may develop as an idiopathic kidney disease, without a known cause. Biopsy may confirm the presence of glomerular scarring if the tissue is taken from the affected section of the kidney. But finding the affected section is a matter of chance, especially early in the disease process, when lesions may be scattered. Confirming a diagnosis of FSGS may require repeat kidney biopsies. No universal remedy has been found, and most patients with FSGS progress to total kidney failure over 5 to 20 years. Treatments involving steroids or other immunosuppressive drugs appear to help some patients by decreasing proteinuria and improving kidney function. ACE inhibitors and ARBs may also be used in FSGS to decrease proteinuria. Treatment should focus on controlling blood pressure and blood cholesterol levels, factors that may contribute to kidney scarring.
Membranous nephropathy, also called membranous glomerulopathy, is the second most common cause of the nephrotic syndrome (proteinuria, edema, high cholesterol) in U.S. Diagnosis of membranous nephropathy requires a kidney biopsy, which reveals unusual deposits of immunoglobulin G and complement C3, substances created by the body’s immune system. Fully 75 percent of cases are idiopathic, which means that the cause of the disease is unknown. The remaining 25 percent of cases are the result of other diseases like systemic lupus erythematosus, hepatitis B or C infection, or some forms of cancer. About 20 to 40 percent of patients with membranous nephropathy progress, usually over decades, to total kidney failure, but most patients experience either complete remission or continued symptoms without progressive kidney failure. ACE inhibitors and ARBs are generally used to reduce proteinuria. Additional medication to control high blood pressure and edema is frequently required. Some patients benefit from steroids, but this treatment does not work for everyone. Additional immunosuppressive medications are helpful for some patients with progressive disease.
Minimal change disease (MCD) is the diagnosis given when a patient has the nephrotic syndrome and the kidney biopsy reveals little or no change to the structure of glomeruli or surrounding tissues when examined by a light microscope. MCD may occur at any age, but it is most common in childhood.