Interleukin 1 receptor antagonist gene polymorphism in women with vulvar vestibulitis

OBJECTIVE: Vulvar vestibulitis is a chronic inflammatory syndrome of unknown cause and pathogenesis. We examined the relation between vulvar vestibulitis and polymorphisms in the gene coding for the interleukin 1 receptor antagonist, a naturally occurring down-regulator of proinflammatory immune responses. STUDY DESIGN: Cells from the lower genital tract of 68 women with vulvar vestibulitis, 343 women with no history of vulvodynia, and 40 women with human papillomavirus cervical infection were tested by polymerase chain reaction for the different alleles of the gene encoding for interleukin 1 receptor antagonist. The presence of human papillomavirus in the specimens was determined by polymerase chain reaction with the use of degenerate consensus primers to the conserved LI gene. RESULTS: Allele 2 of the gene encoding the interleukin 1 receptor antagonist was present in homozygous form in 52.9% of women with vulvar vestibulitis. In marked contrast only 8.5% of the control women and 2.5% of women with human papillomavirus were homozygous for this allele (P less than or equal to.0001). Among the women with vulvar vestibulitis, 57.5% of those without human papillomavirus, as well as 52.2% of those with human papillomavirus, were homozygous for allele 2 of the gene encoding interleukin 1 receptor antagonist CONCLUSION: The unique distribution of interleukin 1 receptor antagonist alleles among women with vulvar vestibulitis suggests that polymorphism in this gene may be a factor influencing susceptibility to this syndrome, severity of symptoms, or both.