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HLA-B27 Check For Ankylosing Spondylitis: Makes use of, Outcomes

Ankylosing spondylitis (AS) is the commonest kind of spondyloarthritis. These are arthritis situations that have an effect on the backbone, sacroiliac (SI) joints, and entheses (the areas the place ligaments and tendons connect to bones).

AS can be an autoimmune illness, that means that the immune system malfunctions and assaults wholesome tissues. It causes irritation that primarily causes ache and stiffness within the backbone and SI joints connecting the bottom of the backbone (sacrum) to the pelvis.

AS is strongly linked to the human leukocyte antigen B27 (HLA-B27) genetic mutation. This mutation is related to the event of the situation. It may additionally be associated to the illness’s severity. HLA genes typically assist the immune system acknowledge and take away international invaders like micro organism and viruses.

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The frequency of HLA-B27 in folks with AS is 85%. HLA-B27 can be present in folks with different varieties of spondyloarthritis, together with psoriatic arthritis (PsA), however the strongest hyperlink to HLA-B27 exists with AS.

Having this gene mutation will increase your threat for AS, however it’s doable to have the gene mutation and by no means get AS or not have it and nonetheless get AS.

If a healthcare supplier suspects you’ve got AS, they could advocate a blood check for HLA-B27. They may make this resolution primarily based in your signs or the outcomes of different exams.

This text covers the aim of HLA-B27 testing, potential dangers and contradictions, what to anticipate earlier than, throughout, and after the check, outcomes, and extra.

Goal of Check

HLA proteins assist the immune system distinguish between wholesome cells and dangerous substances. These proteins are made primarily based on directions from inherited genes.

The HLA-B27 check appears to be like for the HLA-B27 protein discovered on the floor of white blood cells. A healthcare supplier will request this check to evaluate your chance of growing an autoimmune illness like AS. They could additionally use it to substantiate a suspected prognosis of AS.

Testing shall be thought-about when you have signs of AS or one other type of spondyloarthritis. Signs embrace irritation and ache within the backbone, hips, or peripheral (massive joints), eye irritation, and extreme fatigue.

A healthcare supplier may additionally suspect AS if you’re a younger grownup male as a result of AS is extra widespread below age 40 in folks assigned male at beginning.

Dangers and Contraindications

The HLA-B27 includes a blood attract a laboratory or a healthcare supplier’s workplace. Dangers linked to this check and routine blood attracts are minimal.

It’s doable to really feel discomfort when the needle is inserted and the blood is drawn. Some folks may really feel ache on the puncture web site throughout the check.

Blood exams can carry some common dangers, however these are uncommon. These embrace:

  • Issue discovering a puncture web site, leading to a number of needle sticks
  • Delicate ache or bruising the place the needle was inserted
  • Extreme bleeding on the needle web site
  • Fainting or lightheadedness
  • A hematoma—the buildup of blood below the pores and skin
  • An infection on the needle web site

You probably won’t expertise critical issues or unwanted side effects from having an HLA-B27 blood check.

What to Anticipate

An HLA-B27 check will probably happen as soon as. It’d verify a prognosis of AS or rule it out. HLA-B27 testing will not be definitive, but it surely provides an additional layer of data to assist your healthcare supplier attain a prognosis.

HLA-B27 testing sometimes accompanies different exams for autoimmune ailments. Further testing may embrace rheumatoid issue, erythrocyte sedimentation charge (ESR), or C-reactive protein (CRP) blood exams.

Rheumatoid issue is discovered within the blood of individuals with rheumatoid arthritis, a sort of autoimmune arthritis that assaults the synovial linings of the joints. ESR and CRP exams measure irritation within the physique.

Earlier than the Check

The HLA-B27 check requires a normal blood draw. Usually, no particular preparation is important.

Your healthcare supplier’s workplace, a lab, or a hospital might administer the blood check. Ensure you arrive early to test in, fill out any required types, present your insurance coverage card, and pay any co-pays or different prices.

HLA-B27 often doesn’t require you to quick (abstain from meals or drink), however you need to test along with your healthcare supplier to see if it’s worthwhile to cease taking any of your medicines earlier than the check. You may additionally need to keep away from strenuous actions earlier than the blood draw, together with train and heavy lifting.

The technician will often draw the blood out of your arm. Sporting a short-sleeved shirt or a shirt with unfastened sleeves will make your arm extra accessible to them.

Will Insurance coverage Cowl HLA-B27 Testing?

Most insurance coverage will cowl diagnostic blood exams. However some insurance coverage may require preapproval or so that you can pay a co-pay or a portion of the fee. Test along with your insurance coverage firm forward of time to keep away from shock prices.

Through the Check

The HLA-B27 check is a normal blood draw. A phlebotomist (a healthcare employee skilled in drawing blood), lab technician, or nurse performs this.

At first of the blood check, the nurse or technician will clear your arm within the space the place they are going to draw the blood. They may then tie a rubber band to your higher arm and ask you to make a fist to allow them to higher see the veins.

The particular person administering the HLA-B27 check will take a blood pattern from a vein contained in the elbow or the again of the hand utilizing a small needle. The needle is inserted into the vein, and the blood flows gently by a tube.

When the technician has taken the pattern, they take away the needle and rubber band and apply a bandage or clear cotton with medical tape to the needle web site.

You may really feel some ache on the puncture web site throughout the check. Let the particular person administering the blood check know if you happen to really feel dizzy or faint, however unwanted side effects from routine blood exams are uncommon.

After the Check

When the HLA-B27 is full, the technician will advise you to place some strain on the cotton pad or to put on a bandage for a selected time. You also needs to keep away from strenuous exercise or heavy lifting for a number of hours after a blood check to stop bleeding.

Apply an ice pack to your arm if you happen to really feel stiffness or discover any bruising on the needle web site. If stiffness or bruising doesn’t enhance otherwise you expertise swelling in your arm, attain out to a healthcare supplier instantly.

Routine blood exams like HLA-B27 sometimes don’t trigger unwanted side effects or adversarial reactions. Anybody who experiences any worrisome signs following blood work ought to contact a healthcare supplier.

Deciphering Outcomes

About 6% of the US inhabitants is constructive for HLA-B27 (1 in 17 folks). Outcomes from an HLA-B27 check shall be damaging or constructive. Your check outcomes are typically obtainable inside a day, however relying on the placement of your check, they could take longer.

A damaging check consequence means HLA-B27 was not present in your blood, though this doesn’t rule out an autoimmune dysfunction. Your healthcare supplier will contemplate this check consequence, together with signs and extra testing.

In case your HLA-B27 check is constructive, HLA-B27 is current in your blood. Although a constructive check might trigger concern, it doesn’t imply you’ll go on to have ankylosing spondylitis, psoriatic arthritis, or one other autoimmune illness.

To diagnose AS or one other autoimmune dysfunction, a healthcare supplier will depend on your symptom historical past, medical and household historical past, and the outcomes of different blood work and diagnostic exams (ie, X-rays and different imaging).


In case your HLA-B27 is constructive and your healthcare supplier confirms you’ve got ankylosing spondylitis, you’ll get a referral to a rheumatologist. A rheumatologist is an inner drugs physician specializing in musculoskeletal situations, autoimmune ailments, and inflammatory problems in folks of all ages.

Seeing a rheumatologist is essential to managing your AS. They may verify your prognosis and get you began on early, aggressive therapy to decelerate the illness’s development. Delaying the illness prevents joint and backbone injury and different issues, like eye and coronary heart issues.


If a healthcare supplier suspects you’ve got ankylosing spondylitis, they are going to request an HLA-B27 blood check. This blood check appears to be like for HLA-B27 proteins on the floor of white blood cells. HLA-B27 positivity might imply an elevated threat for autoimmune ailments like AS, the place your immune system malfunctions and begins to assault wholesome tissues.

The HLA-B27 check is a routine blood check that requires no preparation. It sometimes includes a blood draw from a vein contained in the elbow or the again of the hand.

The outcomes of the HLA-B27 check are both damaging or constructive. If you happen to check constructive and are experiencing signs of AS or one other autoimmune illness, your healthcare supplier will request additional testing to substantiate a prognosis. HLA-B27 positivity additionally happens in individuals who don’t have autoimmune ailments.

A Phrase From Verywell

While you expertise signs of an autoimmune illness like ankylosing spondylitis, getting a confirmatory prognosis can take time. Diagnostic testing, together with a bodily examination, blood work, and imaging, is likely to be vital.

With some exams, like blood work, you’ll be able to stroll right into a lab for testing and get the outcomes rapidly. You have to make an appointment and wait longer for the outcomes of different exams, akin to magnetic resonance imaging (MRI) or computed tomography (CT). For many individuals, ready for outcomes is among the most tense elements of the diagnostic course of.

The stress you’re feeling ready for check outcomes is regular and skilled by many others in the identical place. When you await solutions, discover methods to distract your self. Spend time with family members, train, or strive rest actions like yoga, deep respiratory, and meditation.

If you happen to discover that ready for solutions turns into overwhelming and you’re struggling to manage, contemplate asking your healthcare supplier for a referral to a counselor or different psychological well being supplier.

Incessantly Requested Questions

  • What does it imply if I’m HLA-B27 constructive?

    The aim of HLA-B27 testing is to search for the presence of the HLA-B27 protein on the floor of white blood cells. If you happen to check constructive for HLA-B27, you may need an autoimmune illness or an elevated threat of autoimmune ailments.

  • Can somebody get a false damaging HLA-B27 check?

    It’s unlikely that you should have a false damaging or false constructive HLA-B27. Even when different members of your loved ones check constructive for HLA-B27, you’ll be able to nonetheless have a damaging check. HLA-B27 will not be at all times handed on from one relative to a different.

  • What situations are linked to HLA-B27?

    The presence of HLA-B27 is linked to sure autoimmune ailments, together with ankylosing spondylitis and several types of autoimmune arthritis. Round 85% of individuals with AS are HLA-B27 constructive.

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