Interleukin-10 promoter polymorphisms influence susceptibility to ulcerative colitis in a gender-specific manner.
OBJECTIVE
Pathological evidence supports a potential role of the pro- and anti-inflammatory cytokine network in the pathogenesis of inflammatory bowel disease (IBD). Moreover, associated studies suggest a possible involvement of cytokine-related genes in IBD susceptibility. In this study, we evaluated the effect of the anti-inflammatory interleukin-10 (IL10) gene on ulcerative colitis (UC).


METHODS
Two functional single nucleotide polymorphisms (-1082 G/A, -819 T/C) in the IL10 promoter in 203 Italian sporadic UC patients and 391 controls were determined using high-resolution melting analysis.


RESULTS
The frequency of the -1082A allele was significantly higher in the UC patients than in controls (p=0.00003); -1082 genotype frequencies were also significantly different between UC patients and controls (p=0.0001). Allele and genotype frequencies of -819 T/C were not significantly associated with UC. Furthermore, the frequencies of haplotypes -1082A/-819C and -1082A/-819T, which have been reported to have a lower promoter activity, were significantly higher in UC patients than in controls (p=0.0004). After gender stratification, we found a significant difference in the -1082A allele (p=0.00004) and genotype (p=0.0002) frequencies only between female UC patients and controls; the same result was obtained for the -1082A/-819C and -1082A/-819T haplotypes (p=0.0006).


CONCLUSIONS
A gender effect is observed, with women of AG/AA IL10 genotypes and AC/AT haplotypes having a higher risk of developing UC at a younger age. This finding could be related to the previously documented lower IL10 production associated with the -1082A allele and to the IL10 down-regulating effect of estrogens.
Neurogenetics Unit, Department of Neurological and Psychiatric Sciences, University of Florence, Italy.
Andrea
A
Tedde
Anna
A
Laura Putignano
Siro
S
Bagnoli
Caterina
C
Congregati
Monica
M
Milla
Sandro
S
Sorbi
Maurizio
M
Genuardi
Laura
L
Papi
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003093:Colitis, Ulcerative / Q000235:genetics*; D005260:Female; D005783:Gender Identity; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D012737:Sex Factors
D016753:Interleukin-10