Safety analysis of the diaphragm in combination with lubricant or acidifying microbicide gels: effects on markers of inflammation and innate immunity in cervicovaginal fluid

Abstract

Objective: Diaphragms are being considered for use with vaginal microbicide gels to provide enhanced protection against sexually transmitted pathogens. The purpose of this study was to determine whether use of a diaphragm with microbicide or placebo gel causes cervicovaginal inflammation or perturbations in cervicovaginal immune defense.

Method of study: Eighty-one non-pregnant women were randomized into three groups and instructed to use Milex (CooperSurgical, Inc., Trumbull, CT, USA)diaphragms overnight for 14 days in combination with one of the two acid-buffering microbicide gels [ACIDFORM (Instead Inc., La Jolla, CA, USA) or BufferGel(trade mark) (BG; ReProtect Inc., Baltimore, Maryland)] or placebo gel (K-Y Jelly); Personal Products Inc., Raritan, NJ, USA). Cervicovaginal lavages (CVLs) were performed prior to study entry and on days 8 and 16. Nine soluble mediators of vaginal inflammation or immune defense were measured in CVLs by Bio-Plex or ELISA.

Results: Use of diaphragms with placebo or microbicide gel was not associated with increased levels of inflammation markers. Concentrations of secretory leukocyte protease inhibitor (SLPI) were markedly reduced in the BG group.

Conclusion: Daily use of a diaphragm with placebo or acidifying microbicide gel did not cause cervicovaginal inflammation. However, diaphragm/BG use was associated with markedly reduced levels of SLPI, an important mediator of innate immune defense. Further studies are warranted to establish the safety of diaphragm/microbicide gel combinations.

Figures

Fig. 1

Inhibition of ELISA and Bio-Plex assays by microbicide and placebo gels. Various concentrations of K-Y, AF and BG, diluted in PBS, were added to assay standards. Readings for standard curves obtained in the presence of gel were adjusted to percentage of normal standard curve (no gel).

Fig. 2

Effects of diaphragm with gel on concentrations of proinflammatory and immunologic markers in cervicovaginal secretions. Box plots representing levels of inflammatory factors (a) and chemokines and SLPI (b) in CVLs of women using diaphragms overnight for 14 days in combination with K-Y (□) (n = 24), AF () (n = 19) or BG () (n = 25) at baseline (prior to diaphragm/gel use) and on day-8 (2–4 hrs after diaphragm/gel removal) and day-16 (24 hrs after diaphragm/gel removal). For each box, the horizontal lines, from bottom to top, represent the 25th, 50th (median) and 75th percentiles; the whiskers delineate the 10th and 90th percentiles; and the filled circles identify outlying values. Significant pair-wise comparisons represent results of post hoc analysis (Scheffé's F-tests) following significant anova (F-test). Concentrations of MIP-1α, TNF-α and RANTES (data not shown) were consistently low and did not differ between time points or treatment groups. In Fig. 2a, significant reductions in IL-1α (P < 0.01), IL-1β (P < 0.01) and granulocyte elastase (P < 0.05) concentrations were observed in Day-8 CVLs compared with Baseline. Levels of IL-1α were significantly lower in Day-8 CVLs when compared with Day-16 (P < 0.05), and levels of granulocyte elastase were significantly lower in Day-16 CVLs when compared with Baseline (P < 0.05). All data were pooled across treatment groups. In Fig. 2b, levels of IL-8 were lowest in Day-8 CVLs from the BG treatment group, and concentrations of SLPI were significantly lower in both Day-8 (P < 0.0001) and Day-16 (P < 0.01) CVLs from the BG treatment group when compared with Baseline. Although there was a statistically significant interaction for MIP-1β, 84% of the MIP-1β values were below the detection limit, and the measured values were low, indicating that this effect is probably biologically insignificant (data not shown).