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.
Gastroenterology and Gastrointestinal Endoscopy Service, IRCCS Fondazione Ospedale Maggiore Policlinico, Mangiagalli, Regina Elena and University of Milan, Milan, Italy. saobo@tiscali.it
Simone
S
Saibeni
Luisa
L
Spina
Tiziana
T
Virgilio
Anna
A
Folcioni
Greta
G
Borsi
Roberto
R
de Franchis
Massimo
M
Cugno
Maurizio
M
Vecchi
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