Crohn's disease incidence evolution in North-western Greece is not associated with alteration of NOD2/CARD15 variants.

Aim: To assess the trends in the incidence of inflammatory bowel disease (IBD) over 23 years in the same area and to identify genetic factors related to incidence evolution.

Methods: Patients with IBD arising from North-western Greece were systematically recorded through the 1983-2005 period. Trends in disease incidence and genetic patterns related to CARD15 variants were documented and correlated.

Results: A total of 447 patients with IBD were recorded (23.5% Crohn's disease, 72.7% Ulcerative colitis and 3.8% indeterminate colitis). Mean annual incidence rates of CD and UC were 0.9/100,000 (95% CI 0.1-1.7) and 2.7/100,000 (95% CI 1.7-4.1) inhabitants, respectively. There was a statistically significant increase of CD incidence (P<0.01) during the study period, in contrast to the UC incidence. There were no statistical differences in CARD15 variants over the study period.

Conclusion: The incidence of CD in North-western Greece has risen disproportionately to that of UC in the 21st century. This is not related to alterations of genetic background though.