There is no single definitive initial test for ankylosing spondylitis (AS). A diagnosis is made based on a combination of a comprehensive medical history, a physical exam, and supporting evidence from imaging and laboratory tests.
At this time, no single test diagnoses ankylosing spondylitis. Your doctor may order a blood test to check for the HLA-B27 gene, which is present in most people with the disease. You may have the HLA-B27 gene and never develop ankylosing spondylitis, but it can give doctors more information when making a diagnosis.
NSAIDs are the most commonly prescribed drugs for a disease similar to AS called nonradiographic axial spondyloarthritis (nr-axSpA). Both prescription and over-the-counter NSAIDs appear safe up to 20 weeks of pregnancy, but may cause serious kidney problems in a fetus if taken longer.
Testing for HLA-B27 may be carried out if AS is suspected. However, this test is not a very reliable method of diagnosing AS because some people can have the HLA-B27 gene variant but not have the condition, and some people can have the condition but do not have the gene variant.
Common bowel problems with ankylosing spondylitis
Some common GI symptoms you may experience related to ankylosing spondylitis include: Diarrhea. Bloating.
Ankylosing spondylitis is a form of reactive arthritis following Klebsiella infection, usually occurring in an HLA-B27-positive individual.
HLA-B27 associated spondyloarthropathies are associated with an altered intestinal microbiota and bowel inflammation.
Corticosteroids. Corticosteroids have a powerful anti-inflammatory effect and can be taken as injections by people with AS. If a particular joint is inflamed, corticosteroids can be injected directly into the joint. You'll need to rest the joint for up to 48 hours after the injection.
Unfortunately, it is not high in all AS patients and even when it is high, it can be from other causes. Other causes of an elevation in the ESR include anemia, infection and cancer. That is not to say that if you have an elevation in your ESR in AS, you need to worry about infection or cancer.
HLA-B27 and Ankylosing Spondylitis
One gene, HLA-B27, is strongly associated with a big family of rheumatic diseases called spondyloarthropathies. It includes: Axial spondyloarthritis. Axial psoriatic arthritis.
The vast majority of women with ankylosing spondylitis can expect to have the same rate of fertility, course of pregnancy and birth, and to give birth to normal healthy babies to the same extent as the normal female population. The chance for the offspring to contract AS later in life is somewhat increased.
A positive test means HLA-B27 is present. It suggests a greater-than-average risk for developing or having certain autoimmune disorders. An autoimmune disorder is a condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue.
July 18, 2025
A new peer-reviewed study published in Arthritis & Rheumatology suggests that ivarmacitinib, a new medication known as a selective JAK1 inhibitor, may be a promising treatment for people with active ankylosing spondylitis (AS). The study was a randomized, double-blind clinical trial.
There are no specific lab tests to identify ankylosing spondylitis. Certain blood tests, including erythrocyte sedimentary rate, also called sed rate, and C-reactive protein (CRP), can check for markers of inflammation, but many different health issues can cause inflammation. Blood can be tested for the HLA-B27 gene.
Serological typing with the microlymphocytotoxicity test (MLCT) and flow cytometry (FC) using HLA-B27 antisera is commonly used for the determination of HLA-B27. However, in some patients tested more than once, negative results have turned out to be positive at following investigations.
Early symptoms of ankylosing spondylitis might include back pain and stiffness, especially in the lower back and hips. These symptoms may be worse in the morning or after periods of inactivity. Neck pain and fatigue also are common.
CRP levels between 1.0–10 mg/dL are moderately elevated, which may be a sign of high disease activity in AS or another health condition. Elevated CRP is associated with increased heart disease risk in AS.
In people with autoimmune disease, the sed rate (ESR) can go up to about 150 millimeters per hour, and the more elevated it is, the higher the inflammation in the body is. “It might set off higher alarms if it comes back in the hundreds and you're investigating whether someone has an autoimmune disease,” says Dr.
IV infusion for ankylosing spondylitis involves administering medication through an infusion pump that drips the medication into a catheter to a syringe and through a hollow needle into the patient's bloodstream. IV infusion therapy options for ankylosing spondylitis include Simponi Aria and Remicade.
For long-term treatment, biologics are generally considered safer than prolonged steroid use. While steroids work quickly to reduce inflammation, they can cause serious side effects when used long-term, including: Bone loss and increased fracture risk. Weight gain and swelling.
Biologic therapy can only be prescribed by a consultant rheumatologist. Your GP cannot offer it to you. If you are not under the care of a rheumatologist do ask your GP to refer you.
Everyone with ankylosing spondylitis experiences a unique combination of symptoms. Lower back pain due to sacroiliitis (painful inflammation in your sacroiliac joints) is the most common AS symptom. The pain can spread (radiate).
In an earlier study HLA-B27 was found to correlate with some subgroups of schizophrenia, having an increased incidence specially in the subgroup of patients with poor prognostic features.
Ankylosing spondylitis (AS) is a condition which affects 20 million people worldwide and is likely caused or initiated by a bowel infection from Klebsiella bacteria.
HLA-B27 complications are associated with with older age, chronic inflammation, and intermediate uveitis. The most common complications were posterior synechiae, cataract, raised intraocular pressure, and cystoid macular oedema. The majority of HLA-B27 uveitis cases have a good visual outcome.