Angiotensin-converting enzyme insertion/deletion gene polymorphism in inflammatory bowel diseases.
BACKGROUND
The renin-angiotensin system is strictly related to the kallikrein-kinin system and both are involved in many physiological and disease conditions and possibly in the pathogenesis of inflammatory bowel disease (IBD). Angiotensin-converting enzyme (ACE) is the pivotal enzyme of the renin-angiotensin system and the main catabolic enzyme of the kallikrein-kinin system. The ACE I/D (insertion/deletion) is a polymorphism of the gene encoding for ACE: participants who are homozygous for the D allele exhibit higher ACE levels, which in turn appear to play a deleterious role in several diseases.


OBJECTIVE
To study the prevalence of ACE I/D polymorphism in IBD patients and its possible association with disease features.


METHODS
A total of 232 IBD patients, 124 with ulcerative colitis (UC) and 108 with Crohn's disease and 99 healthy controls were genotyped for the ACE I/D polymorphism.


RESULTS
DD, ID and II genotypes distribution did not show significant differences between IBD patients and controls: 42.2 vs. 40.4%, 42.7 vs. 47.5% and 15.1 vs. 12.1%, respectively. No significant difference was observed between Crohn's disease and UC patients. Within UC patients, the presence of DD genotype and the carriage of the D allele were significantly associated with the presence of extraintestinal manifestations: odds ratio (OR) 4.08, 95% confidence interval (CI): 1.62-10.28; P<0.003 and OR=3.07, 95% CI: 1.45-6.48; P<0.003, respectively. No significant association was found with other IBD clinical features.


CONCLUSIONS
The ACE I/D polymorphism is not associated with IBDs but the D allele appears to increase the risk of developing extraintestinal manifestations in UC patients.
Saibeni
Simone
S
Gastroenterology and Gastrointestinal Endoscopy Service, IRCCS Fondazione Ospedale Maggiore Policlinico, Mangiagalli, Regina Elena and University of Milan, Milan, Italy. saobo@tiscali.it
Spina
Luisa
L
Virgilio
Tiziana
T
Folcioni
Anna
A
Borsi
Greta
G
de Franchis
Roberto
R
Cugno
Massimo
M
Vecchi
Maurizio
M
D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003093:Colitis, Ulcerative / Q000235:genetics; D003424:Crohn Disease / Q000235:genetics; D005128:Eye Diseases / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics*; D007558:Italy; D007592:Joint Diseases / Q000235:genetics; D008107:Liver Diseases / Q000235:genetics; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D011110:Polymorphism, Genetic; D012871:Skin Diseases / Q000235:genetics; D013927:Thrombosis / Q000235:genetics
D007703:Peptidyl-Dipeptidase A