Term
| What is "Inflammatory Spondyloarthropathy"? |
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Definition
"Seronegative" arthritis that presents with a (-) RF test, peripheral distribution (similar to RA) and SPINAL JOINTS.
Can be
1) Ankylosing spondylitis (AS)
2) Psoriatic arthritis (PsA)
3) Reactive (ReA)
4) IBD-associated
5) Undifferentiated SpA |
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Term
| What epidemiological features define SpA? |
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Definition
1) <40 years old for onset
2) HLA-B27 family clustering
HLA-B27 (+) likely in patients with chronic or relapsing arthritis associated with uveitis, aortitis, sacroliitis and/or spondylitis (present in 8%, of whom 90% never get it)
- 95% of patients with Ankylosing spondylitis have HLA-B27 (+)
- In South Africa, where HLA-B27 is rare, reactive arthritis is rare. |
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Term
What is the role of HLA-B27 in SpA?
What is the "Arthritogenic Peptide Hypothesis"? |
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Definition
1) 44kD MHC-I molecule that associates with B2-microgolbulin
Transgenic rates and mice develop arthritis and spondylitis relate to gene copy number
Some individuals with HLA-B27 can't eliminate infected macrophages (promoting intracellular survival of microbes)
2) HLA-B27 presents "arthritogenic" peptides that bind with arginine at position 2 to glutamine of B27, to CTLs |
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Term
| How does "molecular mimicry" between HLA-B27 and bacterial molecules relate to ReA? |
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Definition
Yersinia and Shigella proteins share AA sequence with HLA-B27.
Self-peptides that share sequence homology with bacterial antigens, that are ALSO natural ligands for B27 may disrupt self tolerance. |
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Term
| Which 2 forms of SpA are most associated with HLA-B27? |
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Definition
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Term
| What is the pathology of Ankylosing Spondylitis? |
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Definition
1) Subchondral bone marrow is targeted by activated CTLs
See granulation tissue and inflammation in sacroiliac joint and inflammation with CTLs is seen at "entheses" (ligament/tendon insertion points into bone)
TNF-a is found in biopsies |
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Term
| What are some clinical features common to all seronegative SpA forms? |
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Definition
1) Sinal (axial) joints affected causing sacroiliitis and spondylitis
2) Inflammatory peripheral arthritis (<5 joints and asymetric)
3) Fibrosis/Calcification causing enthesitis
4) Extra-articular manifestations in mucocutaneous, eyes, genitals, heart and GI
5) (-) RF test and lack of rheumatoid nodules ("mild" abnormality in normal laboratory tests for acute phase, ect.) |
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Term
| How can you tell between RA and AS? |
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Definition
SHORT
Symetric (RA) vs. Asymetic (AS)
RF (RA) vs RF (-) (AS)
Nodules (FA) vs. no nodules (AS)
Polyarthritis (RA) vs. Oligoarthritis (AS)
Sacroiliac (-) (RA) vs. Sacroiliac (+) (AS)
Upper limb (RA) vs. Lower limb (AS)
Aortic insufficiency (only in AS)
Explanation
Run some blood work to start.
RA may have RF (+) and will likely have rheumatoid nodules
SpA will lack these, but may have slightly abnormal tests of acute phase reactants.
On physical exam,
AS presents with asymetric Oligoarthritis (<5 joints) with sacroilliac involvement as well as all spine sites.
RA presents with Symmetric Polyarthritis (>5 joints) with no sacroiliac involvement and only cervical spinal involvement. |
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Term
| How can you tell between Inflammatory and Mechanical back pain? |
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Definition
Inflammatory will present with a past history of back pain, familial linkage, younger age, morning stiffness, extra-articular involvement and positive benefits from exercise.
The opposite is true for mechanical back pain, and it should also present with sensory/motor symptoms. |
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Term
| What physical exam findings would you expect for SpA? |
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Definition
1) Pain at sacroiliac joint (FABER test- flexion, abduction and external rotation)
2) Reduced lumbar spine flexion (Schober test)
3) Reduced chest wall expansion (Costovertebral joint)
4) Increased occiput-to-wall distance (cervical spine) |
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Term
| What Radiological exam findings would you expect for SpA? |
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Definition
1) Enthesitis
2) Enthesophyte (bony spurs-calcification)
3) Sacroiliitis (irregular narrowing and ankylosis-bony bridging at joints)
4) Discitis- erosion at discovertebral junction
5) Bamboo spine and Osteoporosis with vertebral fractures. |
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Term
| What treatments are available for AS? |
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Definition
1) Physical therpay to preseve mobility
2) NSAIDS for pain relief
3) Sulfasalazine/ MTX/ Anti-TNF
4) Knee/Hip replacement |
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Term
| What is the prognosis for patients with AS? |
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Definition
few die
1) Intermittent episodes of acute inflammation of spinal joints slowly becoming an IRREVERSIBLE deformity.
2) Surgical colectomy in UC may result in remission of arthritis, but not in case of Crohn's
3) HLA-B27 in ReA linked to severe disease, as is HIP INVOLVEMENT or ESR, lack of NSAID response, lumbar motility limitation and Dactylitis.
4) onset before 16 is BAD |
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Term
| Would you be more likely to tell a patient with RA or AS that they will return to work? |
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Definition
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