Interleukin-27 polymorphisms are associated with inflammatory bowel diseases in a Korean population.
OBJECTIVE
The cytokine interleukin (IL)-27 is composed of two subunits, Epstein-Barr virus-induced gene 3 (EBI3) and p28, and IL-27 is a novel IL-12 family member that mediates between the innate and adaptive immune systems. We previously identified four polymorphisms in the human IL-27 gene and we suggested that the polymorphism of IL-27 is associated with the susceptibility to asthma. IL-27 transcripts are significantly elevated in active Crohn's disease (CD) but not in ulcerative colitis (UC). To determine whether these IL-27 single nucleotide polymorphisms are associated with the susceptibility to inflammatory bowel disease (IBD), the genotype and allelic frequencies of the IL-27 polymorphisms were analyzed between the IBD patients and the healthy controls.


METHODS
Genotype analysis of the IL-27 gene was performed by the single-base extension (SBE) method. The haplotype frequencies of IL-27 for multiple loci were estimated using the expectation maximization (EM) algorithm.


RESULTS
The genotype frequencies of the g.-964A > G polymorphism in the IBD patients were significantly different from those of the healthy control group (P = 0.001). In both the UC and CD patients, the genotype frequencies of the g.-964A > G polymorphism were also significantly different from the frequencies of the healthy control group (P = 0.009). The frequencies of the AGT and GGT haplotypes were significantly different between the healthy control group and the IBD patient group (P = 0.00004 and 0.021, respectively).


CONCLUSIONS
Our results suggest that the g.-964A > G polymorphism of the IL-27 gene located on the IBD1 locus might be associated with the susceptibility to IBD.
Li
Chun-Shi
CS
Genome Research Center for Immune Disorders, Wonkwang University School of Medicine, Iksan, Chonbuk 570-749, South Korea.
Zhang
Qinggao
Q
Lee
Kwang-Jae
KJ
Cho
Sung-Won
SW
Lee
Kee-Myung
KM
Hahm
Ki-Baik
KB
Choi
Suck-Chei
SC
Yun
Ki-Jung
KJ
Chung
Hun-Taeg
HT
Chae
Soo-Cheon
SC
D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D003424:Crohn Disease / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D007378:Interleukins / Q000235:genetics*; D016015:Logistic Models; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D056910:Republic of Korea / Q000453:epidemiology; D018570:Risk Assessment; D012307:Risk Factors
D007378:Interleukins; C464565:MYDGF protein, human