Interleukin 8 expression in human myometrium: Changes in relation to laboronset and with gestational age

PROBLEM: Preterm labor remains the major cause of perinatal mortality and m orbidity in normally formed babies. The mechanisms involved in the onset of preterm labor are poorly understood, mainly because the mechanisms initiat ing term labor remain ill-defined. METHOD OF STUDY: Human myometrial samples were collected at cesarean delive ry from preterm (26-36 weeks gestation) and term (37-41 weeks) women. Women at term were either non-laboring or laboring. The expressions of interleuk in-8 (IL-8) mRNA and protein were measured by reverse transcrigtase-polymer ase chain reaction and enzyme-linked immunosorbent assay, respectively. RESULTS: The expression of both IL-8 mRNA and protein significantly increas ed in the term laboring group, compared with either the term non-laboring o r preterm groups. Levels of IL-8 expression did not alter with advancing ge stational age. CONCLUSIONS: The increased expression of IL-8 in laboring myometria at term supports the hypothesis that up-regulation of IL-8 has a role in the initi ation of labor in association with an influx of neutrophils and the release of their collagenolytic enzymes into uterine tissues.