Download SDL 20- Ankylosing Spondylitis Seronegative Spondyloarthropathies

SDL 20- Ankylosing Spondylitis
Seronegative Spondyloarthropathies
Family of related disorders that share certain characterisctics (back pain, uveitis, peripheral joint inflammation, GI sx)
Includes: ankylosing spondylitis, Reiter syndrome (or reactive arthritis), psoriatic arthritis, arthritis associated with
inflammatory bowel disease, and undifferentiated spondyloarthropathy
Ankylosing spondylitis is the prototypical seronegative spondyloarthropathy.
Common features (chronic inflammatory diseases)
 Lesions consists of enthesitis rather than synovitis
 There is a tendency to affect spinal joints: sacroiliitis, spondylitis
 Peripheral joints are affected less frequently (approximately in 30% of cases)
 There is a tendency for extra-articular manifestations (such as: eye, heart, lung, kidney)
 Tests for rheumatoid factor are negative (this explains the term “seronegative”)
 There is a strong familial aggregation
 There is a genetic association with HLA-B27
Undifferentiated spondyloarthropathy
Does not meet the criteria for a definitive diagnosis
1. Early stage of seronegative spondyoarthropathy
2. Abortive form of definite seronegative spondyloarthropathy (not the classic picture)
Ankylosing Spondylitis
Chronic, progressive inflammatory rheumatic disease involving sacroiliac joints and axial skeleton
Back pain and stiffness of spine
Oligoarthritis, enthesopathy, and anterior uveitis
Epidemiology
Onset between 20-30 years; men >women
Northern European, Native Americans (most individuals that test positive for HLA-B27 are healthy)
Etiology
Exact cause unknown
Genetics: HLA-B27 subtypes commonly associated with AS (HLA-B*2705, B*2702, B*2704, B*2707)
Environment
Pathology
AS characterized by involvement of enthuses and cartilaginous joints
Entheses point at which a tendon, fascia or ligament, or joint capsule inserts into bone
Enthesitis: inflammation of enthuses
Main enthuses involved in AS= annulus fibrosus of IV dick (central enthuses) and Achilles tendon (peripheral)
Cartilaginous joint arthritis: sacroilitis (sacroiliac joint) and spondylitis (IV joint)
Sacroiliitis is the hallmark of AS; joint space disappears and bone fusion occurs in sacroiliac joint
IV discs:
Ossification of annulus fibrosus: lymphocytic infiltration
Granulation tissue is formed, invades and erodes annulus fibrosus and ultimately undergoes ossification
Forms syndesmophytes (bony outgrowth from a ligament that grow toward each other and create bony bridges)
These bony bridges make the vertebral column stiff
Ossification of nucleus pulposus: fusion and immobilization of vertebrae
Synovial joints in vertebral column:
Enethesitis is predominant
Thorax is converted into a rigid “cage” that constricts respiration and diaphragmatic respiration becomes
predominant
Peripheral enthesitis: inflammation at the site of insertion of ligaments and tendons on to bone, progresses to
granulation tissue and to ossification, resulting in radiological signs of periosteal new bone formation
Painful lesions that are tender with swelling of the tendon or ligament insertion
Achilles tendon insertion, plantar fascia
SDL 20- Ankylosing Spondylitis
Peripheral joint: hips bilaterally
Microscopically: chronic synovitis associated with lymphocyte and plasma cell accumulations within the synovial
membrane and hyperplasia of synovial villi (sometimes erosive change and ankylosis)
End stage: bamboo spine
Rigid spine
 In this stage both the anterior and posterior longitudinal ligament, and annulus fibrosus are ossified.
 Intervertebral discs are present but bridged over at the ends by ossified bars (syndesmophytes).
 Intervertebral discs may have disappeared and the vertebral bodies may be completely fused together
 Apophyseal joints are ossified
 There is total ankylosis, which is associated with osteoporosis
Clinical presentation
General: fever and weight loss may occur during periods of active disease
Inflammatory back pain: pain is mostly located in the sacroiliac joints and spine
Morning stiffness lasting more than 30 minutes, nocturnal back pain, mechanical pain worsens by
activity and improves by rest, improvement of symptoms with moderate physical activity but
not rest, and diffuse nonspecific radiation of pain into both buttocks
Stiffness and pain that awakens patients early in the morning
Physical examination: tender sacroiliac joints (direct or indirect compression)
Deformity of spine (loss of lumbar lordosis and accentuated thoracic kyphosis)
Limited ROM
Schober test: mark at L5, 1 finger 5cm below 10 cm above, this space should increase by 5 cm
Spinal ankylosis: stiffness and forward curvature of the spine (increased thoracic kyphosis)= stooped posture
Anterior chest flattened, abdomen protuberant, breathing diaphragmatic
Extraskeletal manifestations
Ocular involvement: uveitis (iritis or iridocyclitis): inflammation of middle layer of eye (usually anterior)
Acute, unilateral painful red eye with photophobia, increased lacrimation, and blurred vision
Cardiac: fewer than 10% of patients; aortitis, aortic valve insufficiency, AV block
Lung: restrictive lung disease with limited chest expansion
Renal: secondary AA amyloidosis (amyloid deposits), proteinuria, progressive azotemia
Neuro: Cervical fracture C5-C7  quadriplegia; AA subluxation (erosion of dens)
Laboratory studies
Nonspecific: increased erythrocyte sedimentation rate and C-reactive protein
Mild elevation of peripheral blood WBC count, negative Rh factor, negative tests for antinuclear antibodies
Mild anemia of chronic disease in 15%
HLA typing positive in 90-95%
Radiological findings
Most helpful in establishing a diagnosis
Sacroiliac joint: earliest changes (hallmark), bilateral, symmetric, and gradually progressive
Stage 1: Subchondral bony erosion at both joint margins; joint resembles the toothed edge of a saw.
Stage 2: When bony erosions progress they lead to pseudowidening of the sacroiliac joint space.
Stage 3: There is gradual subchondral bony sclerosis and joint narrowing with eventual bony fusion.
Stage 4: Ultimately there is complete bony ankylosis. At the end stage, the sacroiliac joint may be seen
as a thin dense line, or it may not be visible at all.
SDL 20- Ankylosing Spondylitis
Spine: spondylosis starts in the lumbar or thoracolumbar spine and progresses proximally in a continuous fashion
Stage 1: The early stage of spondylitis is manifested as small erosions at the corners of the vertebral
bodies.
The areas are surrounded by reactive sclerosis and have been termed the shiny corner sign or Romanus lesion.
Stage 2: Squaring of the vertebral body is another characteristic feature of AS; it is caused by a combination of
corner erosions and periosteal new bone formation along the anterior aspect of the vertebral body. This is best
seen in the lumbar spine, in which the anterior cortex of the vertebral body normally is concave.
Stage 3: This is followed by syndesmophyte formation; this term refers to the process in which ossification of the
outer fibers of the annulus fibrosis leads to bridging of the corners of one vertebra to another.
Stage 4: Ossification of the adjacent paravertebral connective tissue fibers also occurs. Posterior interspinous
ligament ossification, combined with linking of the spinous process, produces an appearance of a solid midline
vertical dense line on frontal radiographs.
Stage 5: Complete fusion of the vertebral bodies by syndesmophytes and other related ossified areas produces
bamboo spine.
Stage 6: Calcifications of the intervertebral disk may occur at single or multiple levels; they are usually
associated with apophyseal joint and costovertebral joints fusion.
Peripheral enthuses: erosion, periosteal new bone formation, and finally ossification in feet at Achilles and plantar fascia
Disease course and prognosis
Slowly progressive, majority of patients have mild disease and maintain good functional capacity
Mortality 5% due to cervical fractures, neuro defecits, heart failure, renal failure
Reiter syndrome (reactive arthritis)
Definition
Autoimmune condition that develops in response to an infection
Symptoms: urethritis, conjunctivitis or uveitis and arthritis
Aseptic inflammatory polyarthritis that usually follows nongonococcal urethritis or infectious dysentery
Third element of the triad, conjunctivitis, does not occur in all patients
Epidemiology: HLA-B27; 20-40 years old
Clinical manifestations
Usually develops 2-4 weeks after nongonococcal urethritis or infectious dysentery
Urethritis: male patients with mucopurulent discharge; Hematuria secondary ot hemorrhagic cystitis
Females: nonspecific cervicitis
Arthritis: lower extremities (knees, ankles, hips and shoulders, wrist, elbows), asymmetric
Sausage digit
Malaise, fatigue, fever
Large knee effusions in excess 100 mL
Low back pain
Conjunctivitis and iritis
Laboratory findings
Nonspecific; anemia, elevated erythrocyte sedimentation rate or elevated C-reactive protein
Joint fluid: inflammatory synovitis with 15,000-30,000 WBC (2/3 neutrophils)
Glucose is normal, crystals not present
Causative organisms
Chlamydia trachomatis: most common
Neisseria gonorrhoeae
Salmonella, Shigella, Campylobacter and Yersinia
SDL 20- Ankylosing Spondylitis
Pathogenesis
Following an infection in a genetically susceptible person get reactive arthritis
Over 2/3 HLA-B27 positive
Mechanism unknown
Disease course
Reactive arthritis was once considered a benign and self-limited condition, but it is, in fact, neither. A study of 27 Ontario
police officers who developed reactive arthritis after a food poisoning incident showed, 18 officers remained
symptomatic when reassessed five years later; four patients had radiographic changes and four had disease severe
enough to cause them to seek other employment. Fourteen of the 18 officers had evidence of axial disease, including
sacroiliitis and spondylitis.
Psoriatic Arthritis
Common, chronic, relapsing, inflammatory skin disorder
10% of people with psoriasis also experience psoriatic arthritis
Epidemiology
35-55 years; men and women equally effected
Psoriasis affects 2.5% population of North America
Clinical presentation
Arthritis: psoriasis precedes arthritis, 15-20% of patients (5 types)
Symmetrical polyarthritis- This is the most common type. This pattern is similar to a mild rheumatoid arthritis,
and hands, wrists, ankles, and feet joints may be involved. The test for rheumatoid factor is negative.
Asymmetrical oligoarticular arthritis- The digits of the hands and feet are affected, with inflammation of the
flexor tendon and synovium occurring simultaneously, leading to the typical "sausage" appearance (dactylitis).
Distal interphalangeal arthritis- DIP joints are typically involved in osteoarthritis and spared in rheumatoid
arthritis. DIP joint involvement is considered classic and unique to psoriatic arthritis, but it occurs in only 5-10%
of patients.
Arthritis mutilans- Digital joint are involved in this form leading to bone resoprtion (osteolysis) with dissolution
of the joint.
Sacroiliitis and spondylitis- Clinical and radiological evidence of sacroileitis, spondylitis, or both can occur in
conjunction with other subgroups of psoriatic arthritis.
Enthesitis: plantar fascia or Achilles tendons
Extra-articular involvement: ocular involvement with conjunctivitis and acute anterior uveitis
Inflammation of aortic valve root, may lead to insufficiency
Secondary amyloidosis
Pathogenesis
HLA-B27; pathogenesis unknown, autoimmune disease
Enteropathic arthropathies
Articular manifestations of inflammatory bowel disease
Idiopathic inflammatory conditions of the colon and small intestine (Crohn and ulcerative colitis)
IBD-related sacroiliitis is frequently asymptomatic
5-10% of ankylosing spondylitis patients have IBD
2/3 of patients suffering from seronegative spondyloarthropathies have microscopical signs of gut inflammation