If you’re living with systemic lupus erythematosus (SLE or lupus) — or have a loved one who is — you’ve probably heard a lot about blood tests. These lab tests play a big role in getting a diagnosis. They can also help see how active lupus is and check for problems in your organs or blood. But with so many tests and unfamiliar namesit can feel like trying to read another language.

In this articlewe’ll help you understand the most common lupus blood tests and what they reveal about your health. We’ll explain what each test looks for and why your healthcare provider might order it.

Why Blood Tests Matter in Lupus

Lupus is an autoimmune disease. The immune systemwhich usually protects youstarts attacking healthy parts of your body instead. Doctors don’t know exactly what causes lupusbut it may be related to a mix of factors — including your geneshormonesinfectionscertain medicationsand environmental triggers like sunlight. These factors may not cause lupus on their ownbut they might set it off in those who are already at risk. These attacks can cause painswellingand damage to your organsjointsand skin.

Because lupus can affect many parts of the bodythere’s no single test that can diagnose it. Insteaddoctors use a combination of urine and blood testsimaging scans (like X-rays or MRI scans)your medical historyand your symptoms of lupus to make a diagnosis.

The Role of Antibody Testing in Lupus

Antibodies are like your body’s security guards. They find and fight off anything that doesn’t belong — like viruses and bacteria. In autoimmune diseasesthe guards get confused. Instead of going after the bad guysthey attack healthy parts of the bodylike your jointsskinkidneysor blood cells. These confused guards are called autoantibodies.

In other wordsif your immune system is a security teamautoantibodies are the guards who’ve lost their checklist. They start flagging everyone — even the good guys — as threats.

Doctors use antibody tests to look for these autoantibodies in your blood. Finding certain autoantibodies can help diagnose lupus or show how active it is.

Antinuclear Antibodies

The antinuclear antibodies (ANA) test is one of the first blood tests to check for lupus. Antinuclear antibodies attack the nucleuswhich is the control center of your cells.

A positive ANA test result means these antibodies show up in your blood. About 98 percent of people with lupus test positiveso it’s one of the most sensitive and useful tests doctors have for lupus. Howeversome people without lupus also have a positive test result. A positive ANA test result is needed to diagnose lupus — it’s usually the first test doctors order. A negative ANA makes lupus unlikelybased on the latest classification guidelines.

After taking a sample of your bloodthe lab checks how strongly the antibodies show up. This is called a titer. Higher titers may be more likely linked to lupus. The lab also looks at the pattern of ANA antibodies under a microscope. Certain patterns can point to specific antibodies. This can give doctors more clues about your condition and help them choose the right treatment.

Even though the ANA test is importantit’s just one piece of the puzzle. Doctors use it along with your symptoms and other test results to help diagnose lupus.

Anti-Double-Stranded DNA

The anti-double-stranded DNA antibody (anti-dsDNA) test looks for antibodies that attack your DNAthe material that holds your genetic code. This test is more specific to lupus than the ANA test. So if the result is positiveit gives doctors a stronger sign that you may have lupus.

About 30 percent of people with lupus have anti-dsDNA antibodiesand fewer than 1 percent of healthy people do. Sowhile a positive result can help confirm a diagnosisa negative result doesn’t necessarily mean you don’t have lupus.

The anti-dsDNA test is also important if doctors think you may have lupus nephritis — kidney inflammation caused by lupus. High levels of anti-dsDNA are often found during a lupus flareespecially when the kidneys are inflamed.

Anti-Histone Antibodies

Histones are proteins that help keep your DNA packed and organized inside your cells. Anti-histone antibodies attack these proteins.

Anti-histone antibodies most often show up in drug-induced lupus. This type of lupus is caused by certain medicationssuch as some high blood pressure or heart medicines. Fortunatelydrug-induced lupus usually goes away once you stop taking the medicine that causes it. Anti-histone antibodies can also show up in people with SLEbut they aren’t unique to lupusso they can’t confirm a lupus diagnosis on their own.

Antiphospholipid Antibodies

Antiphospholipid antibodies target phospholipidswhich are the fat-like parts of your cells. If you have these antibodiesyour blood is more likely to clot. Somewhere between 33 percent and 50 percent of people with lupus have antiphospholipid antibodies.

Antiphospholipid antibodies raise the risk of blood clotsstrokesmiscarriagesand low platelet (blood cells that help blood clot) counts. There are different types of antiphospholipid antibodies. These include lupus anticoagulantanticardiolipin antibodiesand anti-beta-2 glycoprotein I antibodies. About half of the people with lupus who also have an antiphospholipid antibody will develop a blood clot at some point.

A condition called antiphospholipid syndromewhich affects about 10 percent of people with lupusis linked to antiphospholipid antibodies. Howeverantiphospholipid syndrome can develop with or without lupus. If you’ve had a blood clot or pregnancy lossyour doctor may check for antiphospholipid antibodies using a blood test.

Anti-Ribonucleoprotein Antibodies

Some people with lupus make anti-ribonucleoprotein antibodieswhich react to tiny molecules inside cells called ribonucleoproteins. These molecules help cells process genetic instructions and make proteins.

In lupusanti-ribonucleoprotein antibodies may be linked to skin rashesmuscle achesor Raynaud’s phenomenon. Raynaud’s happens when your fingers or toes don’t get enough blood because of cold or stress. They can turn white or blue and feel numb or tingly. Howevera positive anti-ribonucleoprotein antibody test result isn’t only seen in lupus. It can also show up in people with mixed connective tissue diseaserheumatoid arthritisor scleroderma. Your doctor will review your symptoms and other test results to help decide which condition you may have.

Anti-Ro/SS-A and Anti-La/SS-B Antibodies

Anti-Ro/SS-A and anti-La/SS-B antibodies target proteins inside the cell nucleus. They’re most commonly associated with lupusas well as Sjögren’s disease. Sjögren’s is an autoimmune disease that causes dry eyesdry mouthand sometimesarthritis. One group of scientists named the antibodies anti-Ro and anti-Laafter the first letters of the patients’ names where the antibodies were first discovered. Another group called them SSA and SSBshort for Sjögren’s disease A and Bsince they are linked to that condition. Most doctors use both names. (Note that up until 2024Sjögren’s disease was called Sjögren’s disease.)

Certain anti-Ro antibodies are often found in people who get rashes from being in the sun or have lupus that mainly affects the skin. If you have lupus and break out after being in the sunthis test may help explain why.

Anti-ro/SS-A and anti-La/SS-B antibodies are also important during pregnancy. According to the Hospital for Special Surgerya New York City center that treats joint and autoimmune conditionsif a mother tests positive for anti-Ro or anti-Lathe baby may be at risk for neonatal lupus. If the baby develops neonatal lupusit can cause a temporary rashlow blood countsorin rare casesa serious heart problem.

Anti-Sm Antibodies

Anti-Sm antibodies (short for anti-Smith) are named after a person with lupus named Smith — the first known case where these antibodies were found. They were first discovered in that person’s blood. Anti-Smith antibodies are found almost exclusively in people with lupus. Howeveronly 20 percent of people with lupus have anti-Sm antibodiesso they can’t be used alone to make a diagnosis. While not everyone will test positivevery few people without lupus do — less than 1 percent of healthy individuals. This makes them one of the most specific antibodies for lupus.

Anti-Sm targets a protein linked to DNA inside the cell nucleus. Unlike anti-dsDNAanti-Sm levels don’t change during lupus flares. Sodoctors can’t use it to track disease activity. Stilla positive anti-Sm test result can be a strong sign of lupusespecially if other antibody tests or symptoms are unclear.

AVISE Connective Tissue Disease Test

The AVISE Connective Tissue Disease test is a special type of blood test. It can help your doctor determine whether you have lupus or another autoimmune disease — like sclerodermarheumatoid arthritisor Sjögren’s disease. It’s often used when symptoms are unclear or other lab results don’t give a clear picture. For exampleif you’ve had a positive ANA testbut your diagnosis is still uncertainthis test can offer more insight.

This test looks at several biomarkers in the blood at the same time. One unique marker it measures is a type of protein called cell-bound complement activation product. High levels of these markers — especially EC4d or BC4d — may be linked to a higher risk of long-term lupus complications.

It’s not yet known whether this test can track flaresand it won’t predict every case. Some people with a negative AVISE Connective Tissue Disease test result may still develop lupus. Howeverpeople with a positive result are more likely to be correctly diagnosed within two years.

Talk to Your Doctor

If you’re having symptoms of lupus or have questions about your test resultstalk to your doctor. They can help explain what your results meandecide which tests you may need nextand work with you to find the best care plan. Understanding your blood work is one important step toward getting the right diagnosis and treatment.

Find Your Team

On MyLupusTeamthe social network for people with lupus and their loved onesmembers come together to ask questionsgive adviceand share their stories with others who understand life with lupus.

What antibodies have you been tested for? How did those test results help lead to your diagnosis? Share your experience in the comments belowor start a conversation by posting on your Activities page.