Radiographic sacroiliitis, often asymptomatic, is considered the most frequent extra-intestinal manifestation of Crohn's disease.
The association of sacroiliitis with other clinical features of Crohn's disease are limited.
Association of sacroiliitis with CARD15 polymorphisms has recently been suggested.
|HLA-B27 positivity occurred in 7% of patients with radiographic sacroiliitis|
|Journal of Gastroenterology and Hepatology|
Dr Harald Peeters and colleagues from Belgium evaluated the association of sacroiliitis in Crohn's disease patients with clinical phenotypes, other extra-intestinal manifestation and CARD15 polymorphisms.
The research team assessed radiographs of the sacroiliac joints in 251 Crohn's disease patients from three Belgian university hospitals, scored by 2 rheumatologists.
Clinical features were obtained from medical records.
The researchers found that 43% of patients carried at least 1 CARD15 polymorphism.
The researchers defined sacroiliitis as the presence of at least grade 2 unilateral changes.
Sacroiliitis was diagnosed in 65 of the 244 scorable radiographs (27%).
Only 16 of these patients were previously diagnosed with ankylosing spondylitis.
The researcher observed HLA-B27 positivity in 53% of patients with ankylosing spondylitis.
HLA-B27 positivity occurred in 7% of patients with radiographic sacroiliitis.
The researchers found associations between the presence of sacroiliitis and peripheral arthritis.
Associations between ankylosing spondylitis and uveitis were found.
No associations with other recorded clinical features or with CARD15 polymorphisms were observed.
Dr Peeters' team conclude, "We confirm the high prevalence of radiographic sacroiliitis in a multicenter Crohn's disease cohort.
"Uveitis is only associated with ankylosing spondylitis."
"However, all patients with sacroiliitis are more prone to develop peripheral arthritis during their disease course."
"This suggests similar pathogenetic mechanisms in the development of these extra-intestinal manifestations."
"The previously reported association between sacroiliitis and CARD15 polymorphisms was not confirmed."