Axial spondyloarthritis (also often referred to as axSpA) is a chronic,

autoinflammatory Periodic fever syndromes are a set of disorders characterized by recurrent episodes of systemic and organ-specific inflammation. Unlike autoimmune disorders such as systemic lupus erythematosus, in which the disease is caused by abnormalities of ...

disease predominantly affecting the axial skeleton (

sacroiliac joint The sacroiliac joint or SI joint (SIJ) is the joint between the sacrum and the ilium bones of the pelvis, which are connected by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The ...

s and

spine Spine or spinal may refer to: Science Biology * Vertebral column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoolog ...

). The best-known member of the axial

spondyloarthritis Spondyloarthropathy or spondyloarthrosis refers to any joint disease of the vertebral column. As such, it is a class or category of diseases rather than a single, specific entity. It differs from spondylopathy, which is a disease of the vertebra ...

disease family is

ankylosing spondylitis Ankylosing spondylitis (AS) is a type of arthritis characterized by long-term inflammation of the joints of the spine typically where the spine joins the pelvis. Occasionally areas affected may include other joints such as the shoulders or hip ...

. Axial spondyloarthritis is an umbrella term that was introduced in 2009 to characterize a diverse disease family that share clinical and genetic features, such as the involvement of the axial skeleton. The expression was introduced in order to unify (1) less severe forms of spondylitis, (2) the early phase of ankylosing spondylitis as well as (3) ankylosing spondylitis itself into one term.

Classification

Axial spondyloarthritis can be divided into two classes: # Non-radiographic axial spondyloarthritis (nr-axSpA):
This term encompasses both the early disease stage of ankylosing spondylitis, in which no radiographic changes are visible yet, as well as less severe forms of ankylosing spondylitis. # Radiographic axial spondyloarthritis:
Synonym for ankylosing spondylitis. This class is termed radiographic axial spondyloarthritis due to the unambiguous diagnosis through radiographic changes in the

s and/or spine.

Diagnosis

Management

Traditional NSAIDs and

COX-2 inhibitor COX-2 inhibitors are a type of nonsteroidal anti-inflammatory drug (NSAID) that directly targets cyclooxygenase-2, COX-2, an enzyme responsible for inflammation and pain. Targeting selectivity for COX-2 reduces the risk of peptic ulceration and i ...

NSAIDs are effective for treating axSpA. The potential harms may not differ when compared to a placebo treatment in the short term. Various NSAIDs are equally effective (e.g.: Cox2 NSAIDS and traditional NSAIDS). Continuous NSAID use may reduce radiographic spinal progression, but this requires confirmation. In 201
the American College of RheumatologySpondylitis Association of America
an
Spondyloarthritis Research and Treatment Network
published updated recommendations for the treatment of the condition based un updated literature reviews.

History

In 1984, a joint effort led to the definition of specific classification criteria for ankylosing spondylitis, called the "Modified New York criteria". One of the central New York criteria was the existence of

radiographic Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...

ally visible changes in the

s and/or

, which have formed due to bone fusion, erosion and/or formation caused by the disease. Even though these criteria helped to improve uniformly define ankylosing spondylitis, such radiologic changes often only manifested several years after the first disease symptoms appeared. In order to be able to study also patients with early and less typical forms, new criteria were needed that could identify the disease already at an early stage. In 2009 the Modified New York criteria were extended by a broad set of new classification criteria that aimed to classify patients based on the presence of typical spondyloarthritis disease features. These included inflammatory back pain, family history for axial spondyloarthritis, response to treatment with

nonsteroidal anti-inflammatory drugs Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...

(NSAIDs), history of or current inflammation in the joints (arthritis), tendon-bone attachment of the heel (enthesitis), or eyes (uveitis), bowel (inflammatory bowel disease), skin (psoriasis) or signs of elevated inflammation (

C-reactive protein C-reactive protein (CRP) is an annular (ring-shaped) pentameric protein found in blood plasma, whose circulating concentrations rise in response to inflammation. It is an acute-phase protein of hepatic origin that increases following interleukin-6 ...

and

erythrocyte sedimentation rate The erythrocyte sedimentation rate (ESR or sed rate) is the rate at which red blood cells in anticoagulated whole blood descend in a standardized tube over a period of one hour. It is a common hematology test, and is a non-specific measure of ...

). Important parts of the ASAS axSpA criteria are the

biomarker In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, ...

HLA-B27 Human leukocyte antigen (HLA) B27 (subtypes B*2701-2759) is a class I surface antigen encoded by the B locus in the major histocompatibility complex (MHC) on chromosome 6 and presents antigenic peptides (derived from self and non-self antigens) to ...

and

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...

(MRI). The criteria can only be applied in people that have chronic back pain (at least 3 months duration) started before the age of 45 years and only in those patients that already have a diagnosis of axial SpA. Since the disease ankylosing spondylitis was still defined by the Modified New York criteria of 1984, there was the need to find a new disease term that would also include the less severe forms or early onset of ankylosing spondylitis. This expression was found in the umbrella term axial spondyloarthritis. The 2009 classification criteria are called the ASAS (Assessment of SpondyloArthritis international Society) axial spondyloarthritis criteria.

References

{{Medicine Autoinflammatory syndromes