Elafin (SKALP/Trappin-2/proteinase inhibitor-3) Is Produced by the Cervix in Pregnancy and Cervicovaginal Levels Are Diminished in Bacterial Vaginosis

Objectives. To examine cervicovaginal elafin production in pregnancy and determine its relationship in bacterial vaginosis. Study Design. Samples of cervicovaginal secretions were collected from women with uncomplicated singleton pregnancies (n = 112) below 20 weeks gestation. Bacterial flora was assessed using Nugent's criteria, and levels of elafin were measured by enzyme-linked immunosorbent serologic assay (ELISA). Elafin expression in the cervix was also examined by immunohistochemistry. In vitro expression of elafin was examined using cervix and vaginal cell lines. Results. Elafin is expressed in the cervical glandular epithelium. Elafin was found in all 112 samples of cervicovaginal secretions and levels were diminished in women with bacterial vaginosis (P < .05). Interleukin 1 beta (IL-1 beta) stimulated elafin expression in cells derived from the endocervix, but not in those derived from the vaginal epithelium. Conclusions. Elafin is a component of cervicovaginal secretions in pregnancy, and levels are diminished in bacterial vaginosis. It may be an important component of innate immunity in the lower genital tract.