What is Lupus Nephritis?
Lupus or Systemic Lupus Erythematosus (SLE) is an autoimmune disease where our immune system mistakenly attacks different regions of our body. Lupus nephritis is a disease of the kidneys and a serious complication caused by lupus. In Lupus Nephritis, our immune system starts attacking our kidneys, especially those parts of the kidneys, which are responsible for filtering the blood for waste material. As the kidneys are one of the most vital organs in our body, any damage to them can be very fatal and can make the patient very sick. Patient needs to get regular dialysis and in some cases even a kidney transplant for survival.
Patient with lupus nephritis will have inflammation in the kidneys from lupus due to an overactive immune system where the body produces antibodies, which attack the body’s own tissues (auto-antibodies). This produces a destructive inflammatory reaction in the kidneys and the degree of the kidney damage is proportionate to the degree of the immune abnormalities in patients with lupus.
There are various types of kidney diseases, which are termed as lupus nephritis. Each type is differentiated based on the distinctive patterns of anomalies found on the kidney biopsy. Classification of the kidney biopsy findings is usually done based on the appearance of the immune and tissue abnormalities seen microscopically. Other than various types of lupus kidney diseases, patient can also have other forms of kidney diseases, which are not related to lupus, but nevertheless can occur in patients who are suffering from lupus.
Stages of Lupus Nephritis
Stage-1 Lupus Nephritis: In this stage, the patient has no evidence of lupus nephritis, but has the disease though.
Stage-2 Lupus Nephritis: This stage of lupus nephritis is the mildest and thus is treated easily with corticosteroids.
Stage-3 Lupus Nephritis: This is the earliest stage in advanced lupus, where high amounts of corticosteroids are required. The prognosis is favorable though.
Stage-4 Lupus Nephritis: This stage is an advanced stage and carries a risk of kidney failure. Patients with Stage-4 Lupus Nephritis need increased amount of corticosteroids and immunosuppressive medications.
Stage-5 Lupus Nephritis: In this stage, patient has excessive swelling and protein loss. This stage of lupus nephritis is treated with high amounts of corticosteroids. Immunosuppressive medications may or may not be given.
Symptoms of Lupus Nephritis
Symptoms of lupus nephritis are often the same as seen in other kidney diseases and include:
- Blood in urine (hematuria).
- Dark colored urine.
- Frothy or foamy urine.
- Frequent urination, especially at night.
- Weight gain.
- Puffiness or swelling in the ankles, feet and legs, which worsens as the day progresses.
- High blood pressure (hypertension).
Diagnosis of Lupus Nephritis
Initial signs of lupus nephritis include extremely foamy urine or blood in the urine. Swelling in ankles and feet or hypertension also points towards lupus nephritis.
Blood Tests: Blood tests are done to look for increased levels of waste products, such as urea and creatinine, which will give an idea about the kidney function.
Urine Tests: Urine tests are done to assess the function of the kidneys, as these tests help in identifying the level of white blood cells (WBCs), red blood cells (RBCs) and protein in the urine.
24-Hour Urine Collection: This test is done to assess the ability of the kidney to filter wastes. It also helps in determining the amount of protein collected in the urine in 24 hours.
Iothalamate Clearance Testing: A contrast dye is used in this test to check if the kidneys are filtering properly. The radioactive iothalamate is injected into the blood and the patient is then tested to see how fast the dye is excreted through urine. Testing can also be done to find out how quickly the dye leaves the patient’s blood. This test is considered to be one of the accurate tests for checking the speed of kidney filtration.
Kidney Biopsy: Doing a biopsy is not only an accurate method, but also the most invasive method for diagnosing a kidney disease. A long needle is inserted through the stomach and into the kidney from where samples of kidney tissue are taken and sent to lab for analysis.
Ultrasound: Ultrasound helps with the diagnosis by generating detailed images of the kidney, where if there is any abnormality in the shape and size of the kidney, then it can be easily seen.
Treatment for Lupus Nephritis
Lupus nephritis has no cure. Treatment is done to prevent this disease from worsening. Treatment of lupus nephritis aims at stopping kidney damage to avoid the need for a kidney transplant. Treatment for lupus nephritis is also done to provide the patient relief from the symptoms and consists of medications, which suppress the immune system and reduce inflammation. If lupus nephritis progresses to kidney failure, then patient will need dialysis or kidney transplantation to sustain life.
When deciding on the treatment of lupus nephritis, patient’s general health and lifestyle should be considered. Women who desire to conceive cannot take cyclophosphamide, as this medicine damages the ovaries. If a pregnant woman develops lupus nephritis, then there is a huge risk of injury to the fetus and potentially permanent kidney damage from untreated lupus nephritis. Women with active lupus nephritis should not take birth control pills, which consist of synthetic estrogens.
Treatment for lupus nephritis consists of:
- Decreasing the intake of salt and protein in the patient’s diet.
- Controlling certain diseases, such as hypertension, which can cause further damage to the kidney, is essential. Therefore medications for controlling blood pressure are prescribed.
- Steroids are prescribed for reducing inflammation and swelling. They can be given orally or intravenously.
- Immunosuppressive medicines, which suppress the immune system, are also prescribed for reducing the damage to the kidneys. Some of the immunosuppressants include cyclophosphamide and azathioprine, which can be given orally. In certain situations, cyclophosphamide may be given intravenously in a single large dose.
- Other new, but controversial treatments for lupus nephritis include intravenous immunoglobulin infusions, plasmapheresis and fish oils which contain omega-3 fatty acids.
- There are trials being made to completely reestablish the immune system in patients who are suffering from lupus by using stem cell transplantation and bone marrow transplantation. These treatment methods are still in the preliminary stages and are not yet fully deemed as useful. However, we can safely say that the treatment of lupus nephritis will definitely improve in the years to come.
Prognosis of Lupus Nephritis
The prognosis of lupus nephritis varies from patient to patient. Many patients experience only intermittent symptoms and the damage to the kidney is detected during urine tests only. In severe cases of lupus nephritis, patient is at an increased risk for a loss of kidney function and may need a kidney transplant. Treatment can be done to slow the progression of the disease.
Complications from Lupus Nephritis
Kidney failure is the most serious complication of lupus nephritis. Patients will need regular dialysis or need to undergo a kidney transplant. Dialysis may be the first choice for treatment, however, it does not work indefinitely and kidney transplant is eventually needed.
- National Institute of Diabetes and Digestive and Kidney Diseases. (2021). Kidney Disease Statistics for the United States. https://www.niddk.nih.gov/health-information/health-statistics/kidney-disease