title: Analysis of an interleukin-6 gene promoter polymorphism in women with endometriosis by pyrosequencing.
abstract: Interleukin (IL)-6 has been implicated in the etiology of endometriosis. A single nucleotide polymorphism (SNP) at position -174 in the IL-6 gene promoter appears to influence IL-6 transcription rates in vitro and basal IL-6 levels in vivo. We determined the genotype and the allele frequencies of the -174 IL-6 promoter polymorphism and the corresponding IL-6 serum levels in women with endometriosis. The pyrosequencing technique was used to assess the IL-6 genotypes in 94 women with histologically confirmed endometriosis (study group). A series of 70 healthy women without history of uterine disease served as clinical controls (control group).Allele frequencies for the G allele among women with and without endometriosis were 59.6% and 55.0%, respectively (P =.430; odds ratio [OR] 0.83, 95% confidence interval [CI] 0.53, 1.29). Homozygotes for the protective allele C were present in 17.0% of women with endometriosis and in 18.6% of controls were homozygous for the protective allele C (P =.797; OR 0.90, 95% CI 0.40, 2.02). When patients with various disease manifestations were compared, we found an association between the -174 G allele and chocolate cysts (P =.037). Serum levels of IL-6 were significantly higher in women with endometriosis than in controls (P <.001), with highest levels in women with chocolate cysts. There was no association between serum IL-6 levels and IL-6 genotype. The IL-6 promoter polymorphism -174 G/C does not contribute significantly to overall disease susceptibility but does predispose the carrier to distinct endometriosis with chocolate cysts. A genetically determined high IL-6 response might play a pathogenic role in this disease condition.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Gynecological Endocrinology and Reproductive Medicine, Vienna, Austria.
authors.forename: Fritz
authors.initials: F
authors.lastname: Wieser
authors.forename: Gerhild
authors.initials: G
authors.lastname: Fabjani
authors.forename: Clemens
authors.initials: C
authors.lastname: Tempfer
authors.forename: Christian
authors.initials: C
authors.lastname: Schneeberger
authors.forename: Michael
authors.initials: M
authors.lastname: Sator
authors.forename: Johannes
authors.initials: J
authors.lastname: Huber
authors.forename: Rene
authors.initials: R
authors.lastname: Wenzl
mesh_terms: D000483:Alleles; D004715:Endometriosis / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007247:Infertility, Female / Q000235:genetics; D015850:Interleukin-6 / Q000097:blood / Q000235:genetics*; D010048:Ovarian Cysts / Q000235:genetics; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*
chemical_list: D015850:Interleukin-6