trialport

Find your trial

Systemic lupus erythematosus: a plain-language guide

trialport plain-language guide to Lupus (SLE)
Keith

Systemic lupus erythematosus, usually called lupus or SLE, is a long-term autoimmune condition in which the immune system attacks the body’s own healthy tissue, and it can affect almost any part of the body, most often the skin, joints, kidneys, blood cells, heart, lungs and brain [1,2].

This page provides general information. It does not replace advice from a doctor or another qualified healthcare professional.

Key facts

  • Lupus is an autoimmune condition, meaning the immune system attacks healthy tissue instead of only fighting infection [1,2,5].
  • It can affect almost any part of the body, which is a large part of why it is hard to recognize. Lupus UK calls it “the great imitator” [2,4].
  • Around nine in ten adults with lupus are women, and most people develop it between the ages of 15 and 45 [2,6].
  • Lupus is substantially more common, and often more severe, in Black, Hispanic, Asian and Indigenous populations [11,13,14].
  • There is no single test for lupus, and a positive antinuclear antibody result on its own does not mean a person has it [3,15].
  • Hydroxychloroquine is recommended for nearly everyone with lupus, and taking it consistently is part of the treatment [7].

On this page

What is systemic lupus erythematosus?

Systemic lupus erythematosus, usually shortened to SLE or called lupus, is a long-term autoimmune condition. Autoimmune means the immune system, the body’s defense against infection, mistakenly attacks healthy tissue, causing inflammation and, over time, lasting damage [1,2,5].

Its reach is unusual. Lupus can affect almost any part of the body, including the skin, joints, kidneys, heart, lungs, blood cells and brain, so two people with the same diagnosis can look very different [2]. Lupus UK calls it “the great imitator” [4].

Lupus usually follows a pattern of flares and remission. A flare is a period when symptoms return or worsen; remission is a quieter period when symptoms are mild or absent. Nobody knows why flares start or settle [1,2].

Cutaneous lupus (skin only), drug-induced lupus and neonatal lupus share the name but are different conditions [4,5]. This page is about systemic lupus.

How common is it?

Prevalence means how many people have a condition now; incidence means how many are newly diagnosed each year.

The most complete worldwide modeling study estimates global prevalence at about 43.7 per 100,000 people, roughly 3.41 million, and incidence at about 5.14 per 100,000 person-years. It found no data at all for 79.8 percent of countries [10]. Counts limited to people meeting strict classification criteria are lower: United States registry data give 72.8 per 100,000, about 204,295 people in 2018 [11]. A broader charity estimate covering all forms of lupus puts the United States figure at 1.5 million [6]. Every figure counts diagnosed people, so the real number is probably higher.

Around nine in ten adults with lupus are women, and most develop it between the ages of 15 and 45 [2,6].

Lupus is markedly more common in some populations. United States registries give a prevalence of 230.9 per 100,000 among Black women and 270.6 among American Indian and Alaska Native women, against 84.7 among White women, with Hispanic and Asian or Pacific Islander women in between [11,13]. In UK primary care records, people of Black Caribbean ethnicity had the highest rates [12]. Severity differs too: one registry found kidney disease in 40.5 percent of Black participants against 18.8 percent of White participants [14]. This describes populations and access to care, not individuals.

What causes it?

Nobody knows what causes lupus, and research points to several factors acting together [2,5].

A gene is an instruction inside a cell. Dozens of gene variants, meaning small differences in those instructions, are linked to lupus, though it is not passed down in a simple, predictable way and there is no genetic test for it [4,6]. About 20 percent of people with lupus have a parent or sibling who has it or later develops it, so a family history raises the chance [6].

Hormones appear to play a part. Many immune system genes sit on the X chromosome, of which women have two copies and men one, one explanation offered for the sex difference [4]. Lupus often begins around puberty, after childbirth or at menopause [1,4].

Triggers in the environment include sunlight, viral infections, certain medicines and smoking [1,2]. Nothing a person did caused their lupus, there is no known way to prevent it, and it is not catching [4,5].

What are the symptoms?

Symptoms vary enormously and change over time, and fatigue is reported most often [2,4]. Almost nine in ten people with lupus experience it, and it is not ordinary tiredness that rest fixes [4]. Research describes it as one of the most common and most disabling parts of the condition [30].

Other common symptoms include [1,2,4]:

  • painful, swollen or stiff joints, and muscle pain
  • a rash across the nose and cheeks, called a malar or butterfly rash
  • rashes brought on or worsened by sunlight, called photosensitivity
  • usually painless sores in the mouth or nose
  • hair loss, fever without infection, swollen glands, headaches and low mood
  • fingers and toes changing color in cold or stress, called Raynaud’s phenomenon
  • chest pain on breathing deeply, from inflammation of the lining around the lungs or heart, called serositis

Inflammation can also affect the kidneys, blood cells, heart, lungs and nervous system [2]. Kidney inflammation, called lupus nephritis, is often silent early on, so urine and blood are checked regularly [3]. Our guide to proliferative lupus nephritis covers it.

When to seek urgent help. Get emergency care straight away for a seizure, sudden confusion, a very severe headache, sudden weakness or trouble speaking, chest pain, or severe shortness of breath [2]. Contact the care team urgently about a fever while taking medicines that damp down the immune system, since infection is a known risk [7].

How is it diagnosed?

Lupus is usually diagnosed by a rheumatologist, a doctor specializing in joints, connective tissue and immune conditions, after a referral from a family doctor [3,4].

There is no single test for lupus. A diagnosis is built from the whole picture: symptoms over time, an examination, family history, and blood and urine tests [3].

The first blood test looks for antinuclear antibodies, shortened to ANA, which target the body’s own cells instead of germs. Almost everyone with lupus has a positive ANA [3]. A positive ANA alone does not mean a person has lupus: it is common in healthy people, found in 15.9 percent of those tested in a large United States survey [15].

More specific tests follow: anti-double-stranded DNA and anti-Smith antibodies, closely tied to lupus, antiphospholipid antibodies, which affect clotting, and the complement proteins C3 and C4, often low when lupus is active [3,9]. Urine is checked for protein, and a skin or kidney sample is sometimes taken [3].

Diagnosis is often slow, and many people are told for a long time that nothing is wrong. A United States survey found it takes on average nearly six years from first symptoms to diagnosis, and that 63 percent report an incorrect diagnosis first [6]. That experience is common and it is not the person’s fault. Longer delays are linked with worse disease activity and more damage, which is a good reason to keep asking [16].

How is it treated?

There is no cure, though treatment has improved a great deal and most people can now expect a normal or near-normal lifespan [3,4].

Hydroxychloroquine is the backbone. European guidance recommends it for everyone with lupus, at a target dose of up to 5 mg per kilogram of body weight per day [7]. It works slowly and quietly, so it can feel like it is doing nothing, which is one reason people stop taking it. Taking it consistently is part of the treatment: in pregnancy, low levels from missed doses were linked with a higher chance of early birth [18]. Regular eye checks are needed, since long use carries a small risk to the retina [7].

Steroids, used as a bridge. Corticosteroids calm inflammation quickly, so they are used to control a flare and then reduced promptly. European guidance advises keeping long-term doses at or below 5 mg a day of prednisone or equivalent, and stopping them where possible, since long use is linked with infection, diabetes and lasting damage [7,8].

Immunosuppressants. Methotrexate, azathioprine and mycophenolate calm the overactive immune system and help people come off steroids. Cyclophosphamide is kept for disease threatening an organ, and mycophenolate or low-dose cyclophosphamide anchors treatment of the kidneys [7,26].

Biologics. Belimumab blocks a protein that keeps abnormal immune cells alive, and anifrolumab blocks the receptor for type I interferon, an immune signal that drives lupus [3,21]. European guidance places both alongside conventional immunosuppressants rather than only after them, and adds voclosporin or tacrolimus for the kidneys [7,8]. Rituximab is used where other treatment has not worked [7].

Availability differs between countries. Belimumab and anifrolumab are licensed in the United States and the European Union [21,22,23]. In England, NICE recommends belimumab on the NHS for high disease activity despite standard treatment [19], while its anifrolumab appraisal ended in 2022 with no company submission [20].

Sun protection is treatment, not lifestyle advice. Ultraviolet light can set off rashes and whole-body flares, so daily sunscreen of at least SPF 50, hats and covering clothing are part of the plan. In the UK it is available on prescription [1,2].

Living with lupus

Care is usually shared between a rheumatologist and a family doctor, with other specialists as needed [3]. Learning your own early flare warnings, such as rising tiredness, joint swelling, rash or fever, helps your team act sooner [3]. Pacing rather than pushing through helps with fatigue, smoking makes lupus worse, stress can trigger flares, and telling an employer or school can open the door to changed hours or home working [1,3].

Planning a pregnancy deserves its own conversation. Lupus commonly begins in the years when people may be thinking about children, so the discussion should happen well before conceiving [1,3]. Most women with lupus can have healthy pregnancies when the condition is settled first [3]. Some lupus medicines cannot be used in pregnancy and need changing in advance, while hydroxychloroquine is usually continued [17,18]. Antibody results matter: estrogen-containing contraceptive pills are not advised with antiphospholipid antibodies, and anti-Ro or anti-SSA antibodies mean extra monitoring of the baby [3,17]. Care from an obstetrician experienced in high-risk pregnancy is recommended, and while lupus raises the chance of miscarriage, monitoring means many pregnancies go well [3,4].

Thinking about a clinical trial?

Clinical trials test whether a treatment works and is safe. It helps to take this in steps.

1. Understand what the study is asking

Be clear on:

  • what the researchers want to learn, and what is being studied against what
  • how long it lasts, since lupus studies commonly run a year or longer
  • which visits and tests are involved, how often, and how much travel each one means
  • the possible benefits, and the known and unknown risks
  • what happens when the study ends, including whether treatment continues

2. Consider possible medical suitability

Every trial has rules about who can take part, called eligibility criteria: some describe who can join, others who cannot. For a lupus study they might include meeting the 2019 international classification criteria, a positive ANA or anti-double-stranded DNA result, a disease activity score above a set level, a steroid dose within set limits, background medicines unchanged for a number of weeks, and contraception for some treatments [9]. Studies of newer medicines often exclude people with severe active kidney or brain involvement, since those situations need separate treatment [22].

trialport’s medifit helps people consider information related to possible medical suitability. It does not diagnose a condition, confirm eligibility or replace formal screening by the study team.

Explore systemic lupus erythematosus clinical trials through trialport

3. Consider whether participation fits your life

A study can look right on paper and still be hard in practice. Worth thinking through:

  • how many visits there are, how long each takes, and how far you would travel
  • work, school or caring responsibilities, and realistic time off
  • fatigue and flares, which can make a fixed visit schedule genuinely difficult
  • support from family and friends, and who could come with you
  • how you feel about drips, injections, repeated blood tests or a kidney biopsy
  • whether you understand the study well enough to decide, and whether it feels right now

trialport’s readifit helps people reflect on their understanding, motivation, time, routines, support, emotions and practical arrangements.

4. Ask questions before deciding

Useful questions for a research team:

  • Why is this study being done, and what is already known about the treatment?
  • What would I need to do, and for how long?
  • What are the known risks, and what is still unknown?
  • Could I receive a placebo? A placebo is a dummy treatment with no active medicine, used so researchers can compare results fairly. Would I keep my usual treatment alongside it?
  • Would I have to change or stop hydroxychloroquine, steroids or another medicine?
  • What happens if I flare during the study?
  • How often would I need blood tests, urine tests or scans?
  • Can I leave the study after joining, and what happens then?
  • Who looks after my usual care, and who do I contact out of hours?

Taking part is voluntary. A person can ask questions, speak with people they trust and choose not to participate.

Search for clinical trials at app.trialport.com.

Current research

Study status checked: 3 August 2026. Research moves and what is studied changes, so this list will date. For current information, search at app.trialport.com.

  • CAR T cell therapy is the most closely watched area. A person’s own T cells are collected, changed in a laboratory so they remove the immune cells making harmful antibodies, then given back. A German case series of 15 people with severe autoimmune conditions, eight of them with lupus, reported that all eight reached remission and stopped their immune-suppressing medicines [27]. Later results are more mixed: a 2026 study of six people found improvement overall but variable kidney response [28]. No CAR T cell treatment is approved for lupus anywhere.
  • Newer targeted medicines. Obinutuzumab, an antibody that removes B cells, is approved in the United States for active lupus nephritis and recommended by NICE in England [24,25]. Work also continues on the type I interferon pathway, already targeted by anifrolumab, and on Toll-like receptor 7 [29].

Support and further information

In the United States, the Lupus Foundation of America publishes plain-language material, runs support groups and a health education service, and maintains detailed statistics pages [5,6]. NIAMS, part of the National Institutes of Health, covers symptoms, diagnosis, treatment and daily life [2,3].

In the United Kingdom, Lupus UK is the national charity, with information packs, regional groups and material on light sensitivity, fatigue and work [4]. The NHS lupus page is a short starting point [1].

Coverage elsewhere is uneven, and no global directory was verified for this page.

Well-known people with lupus

Selena Gomez, the singer and actor, announced in September 2017 that she had received a kidney transplant at 24 because of lupus-related organ damage, and has also spoken about the effect of lupus on her mental health [31].

Toni Braxton, the singer, was diagnosed in 2008 and has described repeated hospital stays and emergency heart surgery after a lupus-related complication. She now encourages others to have regular check-ups [32].

Questions people often ask

How serious is lupus?
It varies enormously. Some people have mainly skin, joint and fatigue symptoms; others develop kidney, heart, lung or nervous system involvement [1,2]. Most can expect a normal or near-normal lifespan [4].

I have a positive ANA. Does that mean I have lupus?
No. A positive antinuclear antibody result is common in healthy people, found in 15.9 percent of those tested in one large United States survey [15]. Almost everyone with lupus has a positive ANA, so it is a useful first step, though only alongside symptoms [3].

Is lupus inherited?
Not in a simple, predictable way, and there is no genetic test [4]. Genes do play a part, and about 20 percent of people with lupus have a parent or sibling who has it [6].

Does lupus always affect the kidneys?
No. Kidney involvement is common and often silent early on, so urine and blood are checked regularly [3]. Our guide to proliferative lupus nephritis explains what happens then.

Why did it take so long to be diagnosed?
Lupus copies other conditions, symptoms come and go, and there is no single test [3,4]. A United States survey found it takes on average nearly six years from first symptoms to diagnosis [6]. Being told nothing is wrong is very common.

Is lupus related to scleroderma?
They are separate autoimmune conditions sharing some features, such as Raynaud’s phenomenon [2]. See our guide to systemic sclerosis.

Sources

  1. NHS. Lupus. Page last reviewed 19 July 2023, next review due 19 July 2026. https://www.nhs.uk/conditions/lupus/ Accessed 3 August 2026.
  2. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Systemic Lupus Erythematosus (Lupus): Overview, Symptoms, and Causes. Last reviewed October 2022. https://www.niams.nih.gov/health-topics/lupus Accessed 3 August 2026.
  3. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Systemic Lupus Erythematosus (Lupus): Diagnosis, Treatment, and Steps to Take. Last reviewed October 2022. https://www.niams.nih.gov/health-topics/lupus/diagnosis-treatment-and-steps-to-take Accessed 3 August 2026.
  4. Lupus UK. What is Lupus? Last updated December 2025. https://www.lupusuk.org.uk/what-is-lupus/ Accessed 3 August 2026.
  5. Lupus Foundation of America. What is lupus? Last updated 21 October 2020, medically reviewed 31 July 2020. https://www.lupus.org/resources/what-is-lupus Accessed 3 August 2026.
  6. Lupus Foundation of America. Lupus Facts and Statistics. Last updated 11 April 2025. https://www.lupus.org/resources/lupus-facts-and-statistics Accessed 3 August 2026.
  7. Fanouriakis A, Kostopoulou M, Andersen J, et al. EULAR recommendations for the management of systemic lupus erythematosus: 2023 update. Annals of the Rheumatic Diseases. 2024;83(1):15-29. doi:10.1136/ard-2023-224762. https://pubmed.ncbi.nlm.nih.gov/37827694/ Accessed 3 August 2026. (Abstract read in full; the publisher’s full text was not reachable during this build.)
  8. Moysidou GS, Fanouriakis A. EULAR 2023 Recommendations for the Management of Systemic Lupus Erythematosus: One Step Forward. Mediterranean Journal of Rheumatology. 2024;35(1):63-65. doi:10.31138/mjr.130124.erm. https://europepmc.org/article/MED/38736951 Accessed 3 August 2026.
  9. Aringer M, Costenbader K, Daikh D, et al. 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus. Arthritis & Rheumatology. 2019;71(9):1400-1412. doi:10.1002/art.40930. https://pubmed.ncbi.nlm.nih.gov/31385462/ Accessed 3 August 2026.
  10. Tian J, Zhang D, Yao X, Huang Y, Lu Q. Global epidemiology of systemic lupus erythematosus: a comprehensive systematic analysis and modelling study. Annals of the Rheumatic Diseases. 2023;82(3):351-356. doi:10.1136/ard-2022-223035. https://pubmed.ncbi.nlm.nih.gov/36241363/ Accessed 3 August 2026.
  11. Izmirly PM, Parton H, Wang L, et al. Prevalence of Systemic Lupus Erythematosus in the United States: Estimates From a Meta-Analysis of the Centers for Disease Control and Prevention National Lupus Registries. Arthritis & Rheumatology. 2021;73(6):991-996. doi:10.1002/art.41632. https://pubmed.ncbi.nlm.nih.gov/33474834/ Accessed 3 August 2026.
  12. Rees F, Doherty M, Grainge M, Davenport G, Lanyon P, Zhang W. The incidence and prevalence of systemic lupus erythematosus in the UK, 1999-2012. Annals of the Rheumatic Diseases. 2016;75(1):136-141. doi:10.1136/annrheumdis-2014-206334. https://europepmc.org/article/MED/25265938 Accessed 3 August 2026.
  13. Ferucci ED, Johnston JM, Gaddy JR, et al. Prevalence and incidence of systemic lupus erythematosus in a population-based registry of American Indian and Alaska Native people, 2007-2009. Arthritis & Rheumatology. 2014;66(9):2494-2502. doi:10.1002/art.38720. https://pubmed.ncbi.nlm.nih.gov/24891315/ Accessed 3 August 2026.
  14. Somers EC, Marder W, Cagnoli P, et al. Population-based incidence and prevalence of systemic lupus erythematosus: the Michigan Lupus Epidemiology and Surveillance program. Arthritis & Rheumatology. 2014;66(2):369-378. doi:10.1002/art.38238. https://pubmed.ncbi.nlm.nih.gov/24504809/ Accessed 3 August 2026.
  15. Dinse GE, Parks CG, Weinberg CR, et al. Increasing Prevalence of Antinuclear Antibodies in the United States. Arthritis & Rheumatology. 2020;72(6):1026-1035. doi:10.1002/art.41214. https://pubmed.ncbi.nlm.nih.gov/32266792/ Accessed 3 August 2026.
  16. Kernder A, Richter JG, Fischer-Betz R, et al. Delayed diagnosis adversely affects outcome in systemic lupus erythematosus: cross sectional analysis of the LuLa cohort. Lupus. 2021;30(3):431-438. doi:10.1177/0961203320983445. https://europepmc.org/article/MED/33402036 Accessed 3 August 2026.
  17. Sammaritano LR, Bermas BL, Chakravarty EE, et al. 2020 American College of Rheumatology Guideline for the Management of Reproductive Health in Rheumatic and Musculoskeletal Diseases. Arthritis & Rheumatology. 2020;72(4):529-556. doi:10.1002/art.41191. https://pubmed.ncbi.nlm.nih.gov/32090480/ Accessed 3 August 2026.
  18. Balevic SJ, Weiner D, Clowse MEB, et al. Hydroxychloroquine PK and exposure-response in pregnancies with lupus: the importance of adherence for neonatal outcomes. Lupus Science & Medicine. 2022;9(1):e000602. doi:10.1136/lupus-2021-000602. https://europepmc.org/article/MED/34996856 Accessed 3 August 2026.
  19. National Institute for Health and Care Excellence (NICE). Belimumab for treating active autoantibody-positive systemic lupus erythematosus. Technology appraisal guidance TA752. Published 15 December 2021. https://www.nice.org.uk/guidance/ta752 Accessed 3 August 2026.
  20. National Institute for Health and Care Excellence (NICE). Anifrolumab for treating active autoantibody-positive systemic lupus erythematosus (terminated appraisal). Technology appraisal guidance TA793. Published 8 June 2022. https://www.nice.org.uk/guidance/ta793 Accessed 3 August 2026.
  21. European Medicines Agency. Saphnelo (anifrolumab): medicine overview (EPAR summary for the public). Marketing authorisation valid throughout the EU from 14 February 2022. https://www.ema.europa.eu/en/medicines/human/EPAR/saphnelo Accessed 3 August 2026.
  22. US Food and Drug Administration. SAPHNELO (anifrolumab-fnia) prescribing information, label effective 24 April 2026, retrieved from the openFDA drug label database. https://api.fda.gov/drug/label.json?search=openfda.brand_name:%22SAPHNELO%22 Accessed 3 August 2026.
  23. US Food and Drug Administration. BENLYSTA (belimumab) prescribing information, label effective 20 June 2025, retrieved from the openFDA drug label database. https://api.fda.gov/drug/label.json?search=openfda.brand_name:%22BENLYSTA%22 Accessed 3 August 2026.
  24. US Food and Drug Administration. GAZYVA (obinutuzumab) prescribing information, label effective 19 December 2025, retrieved from the openFDA drug label database. https://api.fda.gov/drug/label.json?search=openfda.brand_name:%22GAZYVA%22 Accessed 3 August 2026.
  25. National Institute for Health and Care Excellence (NICE). Obinutuzumab with mycophenolate mofetil for treating lupus nephritis. Technology appraisal guidance TA1131. Published 12 February 2026. https://www.nice.org.uk/guidance/ta1131 Accessed 3 August 2026.
  26. Sammaritano LR, Askanase A, Bermas BL, et al. 2024 American College of Rheumatology (ACR) Guideline for the Screening, Treatment, and Management of Lupus Nephritis. Arthritis & Rheumatology. 2025;77(9):1115-1135. doi:10.1002/art.43212. https://pubmed.ncbi.nlm.nih.gov/40331662/ Accessed 3 August 2026.
  27. Müller F, Taubmann J, Bucci L, et al. CD19 CAR T-Cell Therapy in Autoimmune Disease: A Case Series with Follow-up. New England Journal of Medicine. 2024;390(8):687-700. doi:10.1056/NEJMoa2308917. https://pubmed.ncbi.nlm.nih.gov/38381673/ Accessed 3 August 2026.
  28. Zhao J, Zhang X, Zhang Y, et al. Heterogeneous responses of IM19 anti-CD19 CAR T-cell therapy in refractory systemic lupus erythematosus: an open-label pilot study and a mini-review. Annals of the Rheumatic Diseases. 2026;85(6):836-847. doi:10.1016/j.ard.2025.12.014. https://pubmed.ncbi.nlm.nih.gov/41644365/ Accessed 3 August 2026.
  29. Vinuesa CG, Shrotri M, Rahman A. TLR7 in systemic lupus erythematosus: genetics and emerging therapies. Nature Reviews Rheumatology. 2026;22(7):479-495. doi:10.1038/s41584-026-01388-0. https://pubmed.ncbi.nlm.nih.gov/42321474/ Accessed 3 August 2026.
  30. Chapman M, Rizvi AM, Qutab M, et al. Factors associated with fatigue in patients with systemic lupus erythematosus in an outpatient tertiary care setting: a cross-sectional cohort study. BMJ Open. 2026;16(1):e104786. doi:10.1136/bmjopen-2025-104786. https://europepmc.org/article/MED/41922052 Accessed 3 August 2026.
  31. Lupus Foundation of America. How Selena Gomez’s Lupus Led to a Kidney Transplant. https://www.lupus.org/personal-stories/how-selena-gomezs-lupus-led-to-a-kidney-transplant Accessed 3 August 2026.
  32. Lupus Foundation of America. Toni Braxton Opens Up About Her Lupus Complications Ahead of Lupus Awareness Month. Published 27 April 2023. https://www.lupus.org/blog/toni-braxton-opens-up-about-her-lupus-complications Accessed 3 August 2026.

Review information

Written by: trialport editorial team
Reviewed by: Keith Berelowitz, Founder and CEO, trialport
Reviewed on: 3 August 2026
Next review due: 3 August 2027
References last checked: 3 August 2026