Perianal disease combined with NOD2 genotype predicts need for IBD-related surgery in Crohn's disease patients from a population-based cohort.
BACKGROUND
Patients with Crohn's disease (CD) often require surgery at some stage of disease course. Prediction of CD outcome is influenced by clinical, environmental, serological, and genetic factors (eg, NOD2). Being able to identify CD patients at high risk of surgical intervention should assist clinicians to decide whether or not to prescribe early aggressive treatment with immunomodulators.


METHODS
We performed a retrospective analysis of selected clinical (age at diagnosis, perianal disease, active smoking) and genetic (NOD2 genotype) data obtained for a population-based CD cohort from the Canterbury Inflammatory Bowel Disease study. Logistic regression was used to identify predictors of complicated outcome in these CD patients (ie, need for inflammatory bowel disease-related surgery).


RESULTS
Perianal disease and the NOD2 genotype were the only independent factors associated with the need for surgery in this patient group (odds ratio=2.84 and 1.60, respectively). By combining the associated NOD2 genotype with perianal disease we generated a single "clinicogenetic" variable. This was strongly associated with increased risk of surgery (odds ratio=3.84, P=0.00, confidence interval, 2.28-6.46) and offered moderate predictive accuracy (positive predictive value=0.62). Approximately 1/3 of surgical outcomes in this population are attributable to the NOD2+PA variable (attributable risk=0.32).


CONCLUSIONS
Knowledge of perianal disease and NOD2 genotype in patients presenting with CD may offer clinicians some decision-making utility for early diagnosis of complicated CD progression and initiating intensive treatment to avoid surgical intervention. Future studies should investigate combination effects of other genetic, clinical, and environmental factors when attempting to identify predictors of complicated CD outcomes.
Genomics Research Centre, Griffith University, Queensland, Australia.
Bushra Farah
BF
Nasir
Lyn
L
Griffiths
Aslam
A
Nasir
Rebecca
R
Roberts
Murray
M
Barclay
Richard
R
Gearry
Rodney A
RA
Lea
D000328:Adult; D001004:Anus Diseases / Q000503:physiopathology*; D016022:Case-Control Studies; D015331:Cohort Studies; D003424:Crohn Disease / Q000235:genetics / Q000503:physiopathology / Q000601:surgery*; D018450:Disease Progression; D005260:Female; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics*; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D012307:Risk Factors
C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein