Lupus Nephritis: Complete Guide to Symptoms, Causes, Diagnosis, and Treatment
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Lupus nephritis is kidney inflammation that happens when lupus autoantibodies attack the parts of the kidneys that filter waste. As many as half of adults with systemic lupus get it. It is diagnosed with blood and urine tests and a kidney biopsy, and although there is no cure, treatment aims for remission and for protecting kidney function [1][2].
Quick Answer: What is lupus nephritis?
Lupus nephritis is kidney inflammation that occurs when the immune system in people with systemic lupus attacks the kidneys' filters. Warning signs include foamy or bloody urine, high blood pressure and swelling. It is diagnosed with blood and urine tests and a kidney biopsy. There is no cure, but treatment aims for remission and to protect kidney function. [1] [2]
What the research says
Adding belimumab to standard therapy improved kidney outcomes at two years. In the phase 3 BLISS-LN trial of 448 adults with biopsy-proven, active lupus nephritis, 43% of patients on belimumab had a primary efficacy renal response versus 32% on placebo, and 30% versus 20% had a complete renal response. The risk of a renal-related event or death was lower with belimumab (hazard ratio 0.51) (Furie et al., N Engl J Med, 2020 [3]).
Voclosporin added to standard therapy raised complete renal response rates at one year. In the AURORA 1 phase 3 trial of 357 patients, 41% (73 of 179) on voclosporin reached complete renal response at week 52 versus 23% (40 of 178) on placebo (odds ratio 2.65), and serious adverse events were similar between the groups (21% each) (Rovin et al., Lancet, 2021 [4]).
For people whose kidneys fail, transplant outperformed dialysis. A systematic review and meta-analysis of 16 comparative observational studies of lupus nephritis-related end-stage kidney disease found that kidney transplant lowered the risks of all-cause mortality, cardiovascular mortality, infection-related mortality, and cardiovascular events compared with dialysis (high certainty) (Kawtharany et al., ACR Open Rheumatol, 2025 [5]).
What Is Lupus Nephritis?
Lupus nephritis is a problem that occurs often in people who have systemic lupus erythematosus, also called lupus. It is not a separate disease. It is what happens when lupus reaches the kidneys [1].
Lupus is an autoimmune disease, which means the body's immune system attacks its own cells and organs. Lupus causes the immune system to make proteins called autoantibodies. These proteins attack tissues and organs in the body, including the kidneys [1].
Lupus nephritis occurs when lupus autoantibodies affect the parts of the kidneys that filter out waste. This causes swelling and irritation of the kidneys, called inflammation. It might lead to blood in the urine, protein in the urine, high blood pressure, kidneys that don't work well, or even kidney failure [1].
How the Kidneys Work
The kidneys remove waste and extra fluid from the blood through filtering units called nephrons. Each nephron contains a filter, called a glomerulus. Each filter has tiny blood vessels called capillaries [1].
When blood flows into a glomerulus, bits of water, minerals, nutrients, and waste pass through the capillary walls. Large molecules, such as proteins and red blood cells, stay in the blood. The filtered molecules then pass into another part of the nephron called the tubule [1].
The water, nutrients, and minerals the body needs are sent back to the bloodstream. The extra water and waste become urine that flows to the bladder and is passed out of the body [1].
Healthy glomeruli keep protein and red blood cells in the blood; in lupus nephritis, autoantibodies damage the filters and protein and red blood cells leak into the urine.
In lupus nephritis, the autoantibodies inflame the glomeruli, the very filters that keep proteins in the blood and pass waste out. When these filters are damaged, protein leaks into the urine and the kidneys lose their ability to clean the blood properly.
Key Facts About Lupus Nephritis
Fact | Detail |
|---|---|
What causes it | Lupus autoantibodies inflaming the kidney's filtering units |
How common in lupus | As many as half of adults with systemic lupus develop it |
Type of condition | Autoimmune kidney disease (a kidney complication of lupus) |
Is there a cure | No cure, but treatment can achieve remission and protect the kidneys |
Possible outcomes without treatment | Blood in urine, protein in urine, high blood pressure, kidney failure |
What are the symptoms of lupus nephritis?
Lupus nephritis, a complication of systemic lupus, causes symptoms such as foamy urine, blood in the urine, swelling and high blood pressure. The symptoms come from the kidneys struggling to filter blood. Signs and symptoms include the following [1]:
Symptom | What it looks like |
|---|---|
Blood in the urine | Urine appears pink, red, or darkened |
Foamy urine | Urine that foams because of too much protein |
High blood pressure | Blood pressure rises as the kidneys lose function |
Swelling | In the legs, ankles, or feet, and sometimes in the hands and face |
High creatinine | High levels of a waste product called creatinine in the blood |
Foamy urine deserves special attention. Healthy kidney filters keep protein in the blood. When the filters are inflamed and damaged, protein leaks into the urine and makes it foam [1].
Swelling happens because damaged filters lose control of water. Extra fluid pools in the legs, ankles, and feet, and sometimes shows up in the hands and face [1].
Warning signs of lupus nephritis: foamy urine, blood in the urine, swelling, high blood pressure, and high creatinine.
When to See a Doctor
If you live with systemic lupus and notice foamy urine, blood in the urine, new swelling in the legs, ankles, feet, hands, or face, or high blood pressure, tell your care team promptly. A high creatinine level on routine blood work also means your kidney function needs a closer look [1].
What causes lupus nephritis?
Lupus nephritis is caused by the same immune-system malfunction that drives systemic lupus. As many as half of adults with systemic lupus get lupus nephritis. Systemic lupus causes the body's immune system to damage the kidneys, and once they are damaged, the kidneys can't filter out waste as they should [1].
The chain of events works like this: lupus makes the immune system produce autoantibodies, which are proteins that attack the body's own tissues. When these autoantibodies affect the glomeruli, the kidney's delicate filtering units, they trigger inflammation. The inflamed filters can no longer hold protein in the blood or pass waste into the urine efficiently [1].
What are the risk factors for lupus nephritis?
The only known risk factors for lupus nephritis are being male and race or ethnicity [1].
Risk factor | What it means |
|---|---|
Being male | Women are more likely to get lupus, but men get lupus nephritis more than women do |
Race or ethnicity | Black people, Hispanic people, and Asian Americans are more likely to have lupus nephritis than white people |
The male risk factor runs opposite to lupus itself. Women are far more likely to develop systemic lupus overall, yet men are more likely to develop kidney involvement [1]. No medications, infections, or behaviors are listed as known risk factors.
What complications can lupus nephritis cause?
Lupus nephritis can cause several serious complications [1]:
Complication | Why it matters |
|---|---|
Hypertension | Damaged kidneys lose control of fluid and blood pressure |
Kidney failure | Progressive filter damage can end the kidneys' ability to clean the blood |
B-cell lymphoma | A higher risk of cancer, especially one that starts in the immune system's B cells |
Heart and blood vessel problems | A higher risk of cardiovascular complications |
High blood pressure and kidney damage can feed each other: damaged kidneys raise blood pressure, and high blood pressure can further strain the filtering units. These complications are why treatment aims to reach remission and protect kidney function [2]. To see how kidney damage is staged over time, read our guide to chronic kidney disease.
How is lupus nephritis diagnosed?
Lupus nephritis is diagnosed with laboratory tests that measure kidney function and a kidney biopsy that confirms the diagnosis. Tests to diagnose lupus nephritis include the following [2]:
Test | What it involves | What it shows |
|---|---|---|
Blood tests | Standard blood panels | How well the kidneys are working, including creatinine levels |
Urine tests | Standard urinalysis | Blood or protein in the urine |
24-hour urine collection | Urine collected over 24 hours | How much protein is being lost and how well the kidneys work |
Kidney biopsy | A small section of kidney tissue is removed and sent to a lab | Confirms the diagnosis and shows how bad the disease is |
The kidney biopsy is the defining diagnostic step. It diagnoses lupus nephritis, and it can also help show how bad the disease is. There can be more than one biopsy over time [2].
Diagnosis moves from blood and urine tests to a 24-hour urine collection and, finally, a kidney biopsy.
What are the treatment options for lupus nephritis?
Lupus nephritis has no cure, but supportive treatments and immune-suppressing medicines can help manage it. Treatment aims to achieve four goals [2]:
Treatment goal | What it means |
|---|---|
Reach remission | Reduce symptoms or make them go away |
Slow progression | Keep the disease from getting worse |
Prevent relapse | Keep symptoms from coming back |
Protect kidney function | Keep the kidneys working well enough to avoid dialysis or a kidney transplant |
Supportive Treatments
In general, these treatments might help people with kidney disease [2]:
Diet changes: limiting the amount of protein and salt in the diet can help the kidneys work better.
Blood pressure medicines: angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) help control blood pressure and also keep protein from leaking from the kidneys into the urine.
Diuretics: these medicines help get rid of excess fluid.
Medicines That Suppress the Immune System
Treating severe lupus nephritis might need medicines that slow or stop the immune system from attacking healthy cells. Medicines often are used together, and sometimes medicines used at first are switched to prevent toxic effects [2].
Medicine | Brand names | Role |
|---|---|---|
Prednisone (steroid) | Rayos | Reduces inflammation and immune activity |
Cyclosporine | Gengraf, Neoral, Sandimmune | Calcineurin inhibitor that slows immune activity |
Voclosporin | Lupkynis | Calcineurin inhibitor approved for adults with lupus nephritis |
Tacrolimus | Astagraf, Envarsus, Prograf | Calcineurin inhibitor that slows immune activity |
Cyclophosphamide | Cytoxan | Strong immune suppressant |
Azathioprine | Azasan, Imuran | Immune suppressant |
Mycophenolate | CellCept | Immune suppressant |
Rituximab | Rituxan | Antibody medicine that targets B cells |
Belimumab | Benlysta | Antibody medicine that blocks a B-cell survival signal |
Ongoing clinical trials are testing new treatments for lupus nephritis [2].
Treatment Options for Kidney Failure
For people who progress to kidney failure, treatment options include two main paths [2]:
Option | What it involves |
|---|---|
Dialysis | Filters the blood through a machine to remove fluid and waste, maintain the right mineral balance, and manage blood pressure |
Kidney transplant | A kidney from a donor replaces the failed organ if the kidneys stop working |
How should you prepare for a lupus nephritis appointment?
If you have lupus, talk with your care team about kidney monitoring as a standard part of your care, since as many as half of adults with lupus develop kidney involvement [1].
What to bring: a list of all your current lupus and blood pressure medicines with doses, recent blood and urine test results, and a symptom log noting foamy urine, swelling episodes, and blood pressure readings.
Questions to ask your care team:
Question | Why it matters |
|---|---|
Should I have blood and urine tests to check my kidney function? | These tests measure how well the kidneys are working |
What creatinine level is normal for me, and how is it trending? | Creatinine is a waste product that builds up when the kidneys filter poorly |
Would a kidney biopsy help show how advanced my kidney involvement is? | A biopsy diagnoses lupus nephritis and shows how bad it is |
Which blood pressure medicine would protect my kidneys best? | ACE inhibitors and ARBs control pressure and reduce protein leakage |
What protein and salt limits should I follow? | Diet changes can help the kidneys work better |
What medicines might treat my lupus nephritis, and can they be combined? | Severe cases might need medicines that are often used together |
What signs mean I should contact you right away? | New swelling, foamy urine, or rising blood pressure should be reported |
If my kidneys decline, when would dialysis or a transplant be discussed? | Knowing the options early can make the path clearer |
How can people live well with lupus nephritis?
Living with lupus nephritis means staying on top of regular testing and working closely with your rheumatology and kidney care teams. Treatment often involves combining medicines, and the first choice is not always permanent, because medicines used at first are sometimes switched to prevent toxic effects. New treatments continue to be tested in clinical trials [2].
Managing a long-term autoimmune condition that affects the kidneys can be demanding, and connecting with lupus and kidney-disease support communities can make day-to-day life easier.
What is the bottom line on lupus nephritis?
Lupus nephritis is the kidney complication of systemic lupus, driven by autoantibodies that inflame the kidneys' filtering units. As many as half of adults with lupus develop it, and it is more likely in men with lupus and in Black, Hispanic, and Asian American people than in white people. Its warning signs, which include foamy urine, blood in the urine, swelling, and high blood pressure, are important to report [1].
Diagnosis through blood tests, urine tests, and a kidney biopsy, followed by treatment aimed at remission, can help protect kidney function [2].
Your next step: request kidney function testing at your next rheumatology visit, and ask whether a kidney-protective blood pressure medicine belongs in your treatment plan [2].
Frequently Asked Questions
What is lupus nephritis?
Lupus nephritis is kidney inflammation that occurs when lupus autoantibodies attack the parts of the kidneys that filter out waste. It is a complication of systemic lupus erythematosus, an autoimmune disease, and it can lead to blood in the urine, protein in the urine, high blood pressure, and even kidney failure.
What causes lupus nephritis?
Systemic lupus causes the body's immune system to damage the kidneys, so the kidneys can't filter out waste as they should. As many as half of adults with systemic lupus develop lupus nephritis as a result of this immune attack on the kidney's filtering units.
Who is at risk for lupus nephritis?
The only known risk factors are being male and race or ethnicity. Although women are more likely to get lupus overall, men get lupus nephritis more than women. Black people, Hispanic people, and Asian Americans are more likely to have lupus nephritis than white people.
What are the symptoms of lupus nephritis?
Symptoms include blood in the urine, urine that foams because of too much protein, high blood pressure, swelling in the legs, ankles, or feet (and sometimes in the hands and face), and high levels of the waste product creatinine in the blood.
How is lupus nephritis diagnosed?
Diagnosis uses blood and urine tests, which may include urine collected over 24 hours, to measure how well the kidneys are working. A kidney biopsy, in which a small section of kidney tissue is removed and sent to a lab, confirms the diagnosis and shows how bad the disease is.
Is there a cure for lupus nephritis?
No. There is no cure for lupus nephritis. Treatment aims to reach remission, keep the disease from getting worse, prevent symptoms from returning, and keep the kidneys working well enough to avoid dialysis or a kidney transplant.
What medicines treat lupus nephritis?
Treatment may include steroids such as prednisone (Rayos), plus immune-suppressing medicines such as cyclosporine, voclosporin (Lupkynis), tacrolimus, cyclophosphamide (Cytoxan), azathioprine, mycophenolate (CellCept), rituximab (Rituxan), and belimumab (Benlysta). Medicines are often used together.
What diet changes help lupus nephritis?
Limiting the amount of protein and salt in the diet can help the kidneys work better. Blood pressure medicines called ACE inhibitors and ARBs also help control blood pressure and keep protein from leaking from the kidneys into the urine.
What happens if lupus nephritis leads to kidney failure?
For people who progress to kidney failure, treatment options include dialysis, which filters fluid and waste from the blood through a machine, and kidney transplant, in which a kidney from a donor replaces the failing organ.
What complications can lupus nephritis cause?
Complications include hypertension, kidney failure, a higher risk of heart and blood vessel problems, and a higher risk of cancer, especially B-cell lymphoma, which starts in the cells of the immune system.
Can you have more than one kidney biopsy for lupus nephritis?
Yes. There can be more than one kidney biopsy over time. Biopsies confirm the diagnosis, show how severe the disease is, and can be repeated as the disease is monitored and treatment is adjusted.
Related Reading
Learn more in our guide to Kidney Biopsy: Purpose, Types, Procedure, Risks and Recovery.
Learn more in our guide to Urine Protein Test: Normal Range, How It's Done and What High Protein Means.
C3 Complement Blood Test: Normal Range and What Low or High C3 Means explains the blood test that measures complement C3 and what low or high levels mean.
C4 Complement Blood Test: Normal Range and What Low or High C4 Means explains the companion complement test and what low or high C4 means.
References
Mayo Clinic Staff. Lupus nephritis - Symptoms and causes. Mayo Clinic. Dec. 23, 2025. https://www.mayoclinic.org/diseases-conditions/lupus-nephritis/symptoms-causes/syc-20354335
Mayo Clinic Staff. Lupus nephritis - Diagnosis and treatment. Mayo Clinic. Dec. 23, 2025. https://www.mayoclinic.org/diseases-conditions/lupus-nephritis/diagnosis-treatment/drc-20446438
Furie R, Rovin BH, Houssiau F, et al. Two-year, randomized, controlled trial of belimumab in lupus nephritis. N Engl J Med. 2020;383(12):1117-1128. PMID 32937045. https://doi.org/10.1056/NEJMoa2001180
Rovin BH, Teng YKO, Ginzler EM, et al. Efficacy and safety of voclosporin versus placebo for lupus nephritis (AURORA 1): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial. Lancet. 2021;397(10289):2070-2080. PMID 33971155. https://doi.org/10.1016/S0140-6736(21)00578-X
Kawtharany H, Jorge A, Azzam M, et al. Renal replacement therapy in lupus nephritis-related end-stage kidney disease: a systematic review and meta-analysis. ACR Open Rheumatol. 2025;7(12):e70121. PMID 41294263. https://doi.org/10.1002/acr2.70121
Medical disclaimer
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. The clinical information in this guide reflects source material last reviewed in December 2025.
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