The Genetics of Postoperative Recurrence in Crohn Disease: A Systematic Review, Meta-analysis, and Framework for Future Work

BACKGROUND: Recurrence following abdominal surgery in Crohn disease is over 50%. The impact of genetics on postoperative recurrence is not well defined. METHODS: A literature search was conducted where inclusion required an assessment, by genotype, of postoperative recurrence. The primary endpoint was odds of surgical recurrence. RESULTS: Twenty-eight studies identified a total of 6715 patients. Thirteen loci were identified as modifying the risk of recurrence. NOD2 was identified as a risk factor for recurrence by multiple works (cumulative odds ratio: 1.64, P = 0.003). CONCLUSIONS: A NOD2 risk allele is associated with recurrence following surgery in Crohn disease. Progress in this area will require standardized reporting in future works.