Crohn's disease is a heterogeneous disorder characterized by diverse clinical phenotypes.
Childhood-onset Crohn's disease has been described as a more aggressive phenotype.
Genetic and immune factors may influence disease phenotype and clinical course.
Dr Marla Dubinsky and colleagues examined the association of immune responses to microbial antigens with disease behaviour.
The researchers prospectively determined the influence of immune reactivity on disease progression in pediatric Crohn's disease patients.
The team collected sera from 196 pediatric Crohn's disease cases and tested for immune responses.
The team tested anti-I2, anti-outer membrane protein C, anti-CBir1 flagellin, and anti-Saccharomyces-cerevisiae using ELISA.
Associations between immune responses and clinical phenotype were evaluated.
The researchers found that 28% developed internal penetrating and/or stricturing disease after a median follow-up of 18 months.
| Patients with 1 positive immune response or more progressed to internal stricturing disease|
|American Journal of Gastroenterology|
Both anti-outer membrane protein C and anti-I2 were associated with internal penetrating or stricturing disease.
The team found that the frequency of internal penetrating or stricturing disease increased with increasing number of immune responses.
The odds of developing internal penetrating or stricturing disease were highest in patients positive for all four immune responses.
Pediatric Crohn's disease patients with 1 positive immune response or more progressed to internal penetrating or stricturing disease.
The team observed that this occurred sooner after diagnosis as compared to those negative for all immune responses.
Dr Dubinsky's team concluded, “The presence and magnitude of immune responses to microbial antigens are significantly associated with more aggressive disease phenotypes among children with Crohn's disease.”
“This is the first study to prospectively demonstrate that the time to develop a disease complication in children is significantly faster in the presence of immune reactivity.”
“This predicts disease progression to more aggressive disease phenotypes among pediatric Crohn's disease patients.”