What is lupus nephritis?
Lupus nephritis is a form of lupus that affects the kidneys. Lupus (systemic lupus erythematosus, or SLE) is a condition that involves the immune system.
Your immune system normally protects you from infections and disease, but if you have lupus, your immune system attacks the healthy tissues of your body instead. This causes swelling and pain, and sometimes leads to other complications.
Lupus can affect the heart, joints, skin, lungs, blood vessels, liver, and nervous system. When lupus attacks the kidneys and causes inflammation, it's called lupus nephritis. This serious and potentially life-threatening condition can lead to kidney failure if it's not managed well.
Nephritis is a common complication of lupus. Around one-third of people with lupus have some kidney damage at the time of diagnosis, and that number grows to more than half within 10 years of diagnosis.
Although SLE is far more common among women, more men develop lupus nephritis than women. Also, the likelihood of developing nephritis is higher for African Americans and Latinos. The reasons aren't fully understood, but they're thought to be linked to genetic, environmental, and hormonal factors.
Lupus nephritis can increase the risk of pregnancy complications, especially if it's active when you conceive. Similarly, pregnancy could worsen lupus nephritis.
In a very few cases, the risks are so high that healthcare providers advise against pregnancy. But by timing pregnancy when lupus is under good control and getting the right care, most women with lupus nephritis can have a successful pregnancy and healthy baby.
What are the symptoms of lupus nephritis?
Lupus can cause rashes and other skin changes, extreme tiredness, fever, and swollen, painful joints. If you have lupus nephritis, you may have additional symptoms that signal kidney problems. These include:
- Swelling in your feet, ankles, legs, fingers, arms, or around the eyes
- Blood in urine
- Foamy urine
- Urinating more, especially at night
- High blood pressure
What tests are needed to check for lupus nephritis?
Your healthcare provider will monitor how well your kidneys function with blood and urine tests during your routine checkups. Your kidneys filter waste products from your blood and eliminate them from your body through urine. Your provider can see how well your kidneys are working with these tests:
- Urine tests. Your provider will spot check your urine to see if it contains protein or red blood cells. Healthy kidneys should keep these in your body, so if they're leaking into your urine, it's a sign that the kidneys aren't functioning properly. If this happens, your provider may ask you to do a 24-hour urine test. In this test, urine is collected several times over a 24-hour period to get more detailed information.
- Blood tests. Your provider will give you a serum creatinine test to measure the level of a waste product in your blood called creatinine. Muscles produce creatinine, one of the substances healthy kidneys filter out. Serum is a component of your blood. It's normal to have a small amount of creatinine in your blood, but a level that's higher than normal could be a sign of kidney disease.
These tests are given regularly to women at risk of lupus nephritis because not everyone who develops the condition gets symptoms. The kidneys are very good at coping, even when they're not working well.
If the tests don't clearly show whether kidney problems are related to lupus or pregnancy, your provider may treat your lupus symptoms anyway. It's possible but very rare for a tissue sample to be taken (kidney biopsy) because bleeding is more likely to cause pregnancy complications.
Your provider uses the results of these tests to grade lupus nephritis on a scale of Class I (mild) to Class VI (advanced). Class VI is also known as end-stage renal disease, and the only treatment is dialysis or a kidney transplant.
How does lupus nephritis affect my pregnancy?
A lot depends on whether your lupus nephritis was active when you conceived. Ideally, it's best to have your nephritis under control (in remission) for at least six months before you become pregnant. If this was the case for you, your risk of complications is lower than if your you had active lupus.
If lupus nephritis was active at conception, you're probably facing an increased risk of complications, such as preterm delivery, preeclampsia, and growth problems with your baby. Having active lupus nephritis at conception also increases the risk of pregnancy loss.
Either way, it's likely that you'll be cared for by a maternal-fetal medicine specialist, an obstetrician who specializes in high-risk pregnancies. You'll also see your rheumatologist or a nephrologist regularly during your pregnancy.
What are common pregnancy complications of lupus nephritis?
One of the potential complications your healthcare provider will be concerned about is preeclampsia and a related condition called HELLP syndrome. Not only is preeclampsia more common in women with lupus nephritis, but it's also very difficult to diagnose because many signs of preeclampsia, such as high blood pressure and protein in the urine, are common to both conditions.
Because you have an increased risk of developing preeclampsia, your provider will likely recommend that you take low-dose aspirin during your pregnancy. Even so, watch out for the signs and symptoms of preeclampsia, and contact your provider quickly if you think you may be developing it.
How will my pregnancy affect my lupus nephritis?
Pregnancy puts an extra strain on your kidneys because of the many changes that come with a growing baby. These can include:
- Lupus flare. Pregnancy can increase the risk of a lupus nephritis flare. Estimates vary, but the risk may be as high as 70 percent in women with active disease. The risk remains high throughout pregnancy and in the months beyond.
- Kidney infections. Hormone changes, plus the pressure of your growing uterus on your urinary tract, can make you more susceptible to kidney infections.
- Kidney function loss. Your kidney function may deteriorate during pregnancy, especially if you develop preeclampsia. Most of the time kidney function improves after delivery, but some loss can be permanent.
What is the treatment for lupus nephritis during pregnancy?
If your lupus nephritis has been in remission at least six months prior to your pregnancy, you may not need any treatment. You'll be monitored closely to ensure your kidneys are functioning well and to spot the early signs of a flare.
If lupus becomes active during pregnancy, your provider will try to control it with hydroxychloroquine first. This is a low-risk drug to take during pregnancy, and it's effective at controlling lupus when taken regularly.
If you have a lupus nephritis flare, your provider will likely recommend that you take corticosteroids to suppress your immune system and prevent it from attacking the kidneys. This may be combined with another immunosuppressive medication called azathioprine.
You'll have frequent blood and urine tests to check that the treatment is working. If medication doesn't bring nephritis under control, your provider may recommend delivering your baby early.
Babies born a few weeks early are usually healthy, but sometimes women with lupus nephritis may need to deliver around 24 to 28 weeks. A baby born this early will need to spend some time in the neonatal intensive care unit (NICU), and although there are risks of long-term health problems, most babies are able to go home around their original due date.
Once you've had your baby, your provider can treat your nephritis more effectively.
How do I have a healthy pregnancy if I have lupus nephritis?
Because you have a high-risk pregnancy, it's important that you see your provider regularly. You'll need to follow her advice and take your medication as prescribed. Also, let your provider know promptly if you develop any new symptoms.
In addition, you can take some other steps to help yourself stay well.
- Get plenty of rest. Both pregnancy and lupus can leave you feeling drained and exhausted. Though you may feel there's a lot to do to get ready for your baby, protecting your health should be your top priority. Balance periods of rest with moderate exercise when you feel up to it.
- Take care of your emotions. Having a high-risk pregnancy can be an emotional roller coaster. Manage stress by getting support from family and friends and connecting with other pregnant women who have lupus in the our site Community. Mention your feelings to your provider if they interfere with daily life because you could have depression.
- Protect yourself from the sun. Ultraviolet rays can trigger a flare for people with lupus, so cover up and wear plenty of sunscreen with SPF 50 or higher whenever you're outside.
Having a healthy pregnancy isn't only about managing lupus nephritis. Other steps, such as taking a prenatal vitamin supplement containing folic acid and eating a healthy diet, are important too.
Visit the Society for Maternal-Fetal Medicine's website for more information and to find an MFM specialist near you.