What is Lupus Nephritis?
You have likely heard of lupus and know that it can affect various organs of the body. So, what is lupus nephritis? Lupus nephritis develops when lupus affects the kidneys.
What is Lupus Nephritis and How Does It Develop?
It is a common but serious complication that develops because of systemic lupus erythematosus (SLE). SLE develops when the body mistakenly attacks various tissues of the body. When the body mistakes the tissues of the kidneys for a foreign body, lupus nephritis develops.
This condition is extremely dangerous because it can affect the body’s ability to:
- Control blood pressure.
- Control blood volume.
- Regulate hormone levels.
- Maintain the correct amount of body fluids, such as salts, minerals and acids.
What Causes Lupus Nephritis?
Those with SLE are likely to develop lupus nephritis; in fact, over half of people with SLE go on to develop this condition.
There are few risk factors for the development:
- Though women are more likely to develop SLE, men are more likely to develop it.
- Those who are Black, Hispanic, Latino and Asian American are more likely to develop lupus nephritis than those who are white.
Top 3 Symptoms of Lupus Nephritis
It typically occurs about five years after SLE develops. Unfortunately, sometimes lupus nephritis is the first symptom of SLE.
1. Edema
This condition can cause swelling of the feet and ankles. About 50% of people with lupus will develop edema.
When it develops, it means that the kidneys are not working at their full capacity. This can cause fluid to build up in the body because the kidneys are not filtering toxins properly.
When edema occurs because of lupus nephritis, it commonly occurs in the feet and ankles. However, it can also occur in other areas, such as the legs, eyelids and other, random, areas of the body.
Though lupus nephritis can be one of the most common causes of edema development in those with lupus, taking NSAIDs to control pain can also cause swelling.
2. Hypertension
Hypertension is extremely prevalent in those with this condition; in fact, about two-thirds of those with lupus nephritis are diagnosed with hypertension. Unfortunately, having hypertension increases the risk for cardiovascular disease.
Hypertension related to SLE can be due to a variety of causes:
- Side effects of medications, such as glucocorticoids and cyclosporine.
- Increase in vascular stiffness due to endothelial dysfunction.
- Kidney disease, such as lupus nephritis.
Interestingly, people seem to have hypertension when their disease state is severe. Conversely, having hypertension appears to affect the prognosis of lupus nephritis.
3. Foamy Urine
Foamy urine is caused by excess proteins in the urine, called proteinuria. Proteinuria develops when there is damage to the kidneys.
Protein is typically found in the blood. It serves a variety of functions, such as helping combat infections, regulating the fluid levels of the blood and repairing tissues. However, protein should remain in the urine. When it leaves the blood and exits the body through the urine, proteinuria develops.
Cleveland Clinic states, “Normally, glomeruli, which are tiny loops of capillaries (blood vessels) in the kidneys, filter waste products and excess water from the blood. Glomeruli pass these substances, but not larger proteins and blood cells, into the urine. If smaller proteins sneak through the glomeruli, tubules (long, thin, hollow tubes in the kidneys) recapture those proteins and keep them in the body. However, if the glomeruli or tubules are damaged, if there is a problem with the reabsorption process of the proteins, or if there is an excessive protein load, the proteins will flow into the urine."
Though there are many causes of proteinuria, damage to the kidneys is one of the major causes.
Tips for Seeking a Diagnosis
If you suspect you are at risk, you should speak with your healthcare provider immediately. Proper treatment is imperative – it can help prevent further damage to the kidneys. Untreated, it can increase the likelihood of requiring hemodialysis or the need for a kidney transplant.
If your provider suspects that you have lupus, you will likely have a variety of testing.
Lab Tests
A variety of lab tests are performed to determine the diagnosis as well as the functioning of the kidneys:
- Antibody testing, as it detects various proteins that are made by the immune system. These proteins would typically be present if you have lupus nephritis.
- Labs that evaluate how the kidney is functioning, such as a renal function panel (RFP) or a complete metabolic panel (CMP).
- Urinalysis, as it detects the measure of waste in the urine, as well the presence of abnormal substances.
- Urine protein testing, as it detects the presence of protein in the urine.
- A kidney biopsy. This is the most definitive test for the diagnosis of lupus nephritis. Not only can it aid in the diagnosis, but it can help detect the severity of the illness.