Axial and Peripheral Spondyloarthritis

Question 1

Spondyloarthritis

Answer 1

Chronic inflammatory arthritis affecting spine of young patients
Main symptom is chronic low back/buttock pain
Often associated with other autoimmune diseases (uveitis, psoriasis, IBD)

Question 2

Tests we can use to help diagnose SpA

Answer 2

Imaging (x ray, CT, MRI) of the SI joints

HLA-B27

Question 3

Demographics of SpA

Answer 3

Classically male > female
Typically affects ages 20-40
Prevalence ~1% in NA

Question 4

Manifestations of SpA

Answer 4

Peripheral arthritis
Uveitis
Enthesitis
Colitis
Dactylitis
Psoriasis
Death from heart attacks and strokes
Spine fractures

Question 5

What is the risk that someone has SpA if they have chronic back pain?

Answer 5

5%

Question 6

5 qualities of inflammatory back pain

Answer 6

Onset of symptoms < 40 years, duration > 3 months
Insidious onset
Improves with exercise
No improvement with rest
Pain at night and improves upon getting up

Question 7

HLA-B27

Answer 7

A gene for a protein that presents antigens to T cells
Strongly associated with ankylosing spondylitis
(But 99% of people who are B27+ will not get AS)

Question 8

4 theories of how HLA B27 causes disease

Answer 8

1. Shapes the gut microbiome causing increased production of IL 23 and 17
2. Misfolds in the ER causing increased production of IL 23 and 17
3. The heavy chain can homodimerize and activate immune responses
4. Recognizes an arthritogenic peptide

Question 9

Screening for spondylitis

Answer 9

Symptom onset < 45 years and duration of back pain > 3 months AND
1 of: AM stiffness >30 mins and back pain improves with activity, B27+, IBD, psoriasis, uveitis