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Basic science: Obstetrics
Among pregnant women with bacterial vaginosis, the hydrolytic enzymes sialidase and prolidase are positively associated with interleukin-1β

Some data in this paper were presented in preliminary form at the 25th Annual Meeting of the Society for Maternal–Fetal Medicine, Reno, NV, Feb. 7-12, 2005, abstract 426.
https://doi.org/10.1016/j.ajog.2007.05.035Get rights and content

Objective

The objective of the study was to explore the mechanisms of local innate immunity induction and modulation in pregnant women with bacterial vaginosis (BV).

Study Design

A total of 200 singleton pregnant women in early gestation (12 ± 4 weeks) with BV (Nugent 7-10) without concurrent vaginal infections with Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, syphilis, and yeast. Concentrations of vaginal interleukin (IL)-1β and IL-8, the number of neutrophils, and the levels of sialidase and prolidase hydrolytic enzymes were determined in vaginal fluid.

Results

Concentrations of vaginal IL-1β had a strong positive correlation with levels of sialidase (P < .001) and prolidase (P < .001). Conversely, such enzymes were negatively correlated with the ratio of IL-8/IL-1β (both P < .001) and were not significantly associated with concentrations of IL-8. Notably, the number of vaginal neutrophils had a negative correlation with sialidase (P = .007).

Conclusion

The strong induction of IL-1β in BV-positive women appears to be associated with the production of the hydrolytic enzymes sialidase and prolidase by BV-associated bacteria. However, these 2 enzymes may inhibit the expected amplification of the proinflammatory IL-1β cascade as evaluated by the down-regulation of the IL-8/IL-1β ratio. A blunted response to IL-1β signals may cause the poor rise of neutrophils, which is peculiar to BV. This impairment of local defense may contribute to increased susceptibility to adverse outcomes in BV-positive pregnant women.

Section snippets

Study design

All women enrolling for prenatal care at 3 hospital-based clinics and 1 community-based clinic located in Philadelphia between January 2002-September 2004 were screened for eligibility. Eligible women were enrolled after completing an informed consent as per the institutional ethics committees guidelines. Women were considered eligible for participation if they: (1) were at less than 20 weeks’ gestation at the time of enrollment; (2) spoke either English or Spanish; (3) had a singleton

Results

A total of 1961 eligible women came for their antenatal visit between January 2002-September 2004. Of these women, 1804 (92%) subsequently consented to participate. BV diagnosis was not obtained for 19 of enrolled women (1.1%). A full 44% (n = 802) of study participants were diagnosed with BV (Nugent score 7-10). Among this group, we analyzed host microbial and immune parameters and abstracted medical records for a random subset of 265 women. For this analysis, to minimize potential confounding

Comment

Evidence is accumulating in support of an interrelationship between the host and the microbiological milieu in BV.2, 8, 9, 13, 22, 33 Very recent research highlights a vast heterogeneity in response to microbes among women with BV, which cannot be appreciated by common clinical criteria used to diagnose this condition. Although many aspects of BV remain enigmatic,1, 4, 9, 11 an understanding of the mechanisms that regulate the homeostasis of vaginal microbial flora and local immunity could lead

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    Cite this article as: Cauci S, Flatow Culhane J, Di Santolo M, et al. Among pregnant women with bacterial vaginosis, the hydrolytic enzymes sialidase and prolidase are positively associated with interleukin-1β. Am J Obstet Gynecol 2008;198:132.e1-132.e7.

    Supported in part by the Centers for Disease Control and Prevention/Association of Teachers of Preventive Medicine TS-0626 and TS-0561. The authors do not have a commercial or other association that might pose a conflict of interest.

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