Hormonal contraceptive use modulates the local inflammatory response to bacterial vaginosis

To compare cervical concentrations of numerous cytokines/chemokines in women with bacterial vaginosis (BV) compared with the levels detected after BV resolution and determine if hormonal contraceptive use modulates the local inflammatory response to BV.

Cervical secretions from 81 women with BV at enrollment and normal flora at one-month follow-up were analysed for 10 different cytokines/chemokines using multiplexed fluorescent bead-based immunoassays.

BV was associated with significantly higher concentrations of IL-1 beta, tumour necrosis factor (TNF), interferon-gamma, IL-2, IL-4, and IL-10 compared with the levels detected in the presence of normal vaginal flora. Analysis of results stratified by contraceptive practice demonstrated significantly lower levels of numerous cytokines among women with BV using hormonal contraceptives compared with those women with BV not using hormonal contraceptives. Hormonal contraceptive use was also associated with a statistically significant lesser change in TNF levels between the two study visits compared with the amount of change detected between visits among women who denied their use.

Despite increases in the levels of both pro and anti-inflammatory cytokines in the lower genital tract of women with BV, the overall balance of these two types of molecules was maintained. The character of this local inflammatory response may help explain the typical absence of overt signs of inflammation among women with BV. In addition, hormonal contraceptive use was associated with significantly lower levels of the pro-inflammatory molecules TNF, interferon-gamma, and granulocyte macrophage colony-stimulating factor in women with BV, but did not significantly reduce the levels of IL-10, a key anti-inflammatory cytokine. These results suggest the possibility of an association between hormonal contraceptive use and altered genital tract immunity.