Neither vaginal nor buccal administration of 800 μg misoprostol alters mucosal and systemic immune activation or the cervicovaginal microbiome: a pilot study

Abstract

Objectives: The aim of the study was to assess the extent to which misoprostol alters mucosal or systemic immune responses following either buccal or vaginal administration.

Methods: This was a prospective, crossover pilot study of 15 healthy, reproductive-age women. Women first received 800 μg misoprostol either via buccal or vaginal administration and were crossed over 1 month later to receive the drug via the other route. Cervicovaginal lavage samples, cervical Cytobrush samples, cervicovaginal swabs, urine and blood were obtained immediately prior to drug administration and the following day. Parameters assessed included urine and cervicovaginal misoprostol levels, whole blood cytokine responses (by ELISA) to immune stimulation with lipopolysaccharide, peripheral blood and cervical lymphocyte phenotyping by flow cytometry, cervicovaginal antimicrobial peptide measurement by ELISA and vaginal microbial ecology assessment by 16S rRNA sequencing.

Results: Neither buccal nor vaginal misoprostol significantly altered local or systemic immune and microbiological parameters.

Conclusion: In this pilot study, we did not observe significant alteration of mucosal or systemic immunology or vaginal microbial ecology 1 day after drug administration following either the buccal or vaginal route.

Keywords: Abortion; microbial ecology; mucosal immunology; prostaglandins.

Figure 1

Local and systemic misoprostol concentrations before and after a single buccal or vaginal dose. Mass spectrometry was used to measure misoprostol in both (A) CVL and (B) urine before (pre) and 24 h after (post) administration. Data are shown as box-and-whisker plots (the line represents the median, the boxes represent the 25th–75th percentiles, the whiskers represent the 10th–90th percentiles, and the <10th and >90th percentile outliers are shown as dots). ****p<0.0001 by Mann–Whitney non-parametric testing.

Figure 2

Misoprostol does not alter whole blood responses to LPS. Whole blood was stimulated for 4 h with LPS 1000 ng/ml, and extracellular TNF-α (A) and IL-10 (B) were measured by ELISA. ***p<0.001 by paired, non-parametric Wilcoxon matched pairs test between vehicle (RPMI medium) and LPS for each treatment route.

Figure 3

Misoprostol did not alter CVL levels of trappin-2 (elafin). Levels of trappin-2 were measured in CVL at baseline and 24 h after either buccal or vaginal administration of misoprostol 800 μg. Data are shown as box-and-whisker plots (the line represents the median, the boxes represent the 25th–75th percentiles, the whiskers represent the 10th–90th percentiles, and the <10th and >90th percentile outliers are shown as dots). The data were not statistically different.

Figure 4

No effect of administration of misoprostol on T cell markers of activation. The expression of CD38 (A) and PD-1 (B) on peripheral blood CD4+ T cells was measured at baseline (D0) and 24 h after (D1) either buccal or vaginal administration of misoprostol 800 μg (p=NS for each comparison; Wilcoxon matched pairs test).

Figure 5

Cervical T cells predominantly display an activated memory phenotype compared with peripheral blood T cells. Comparison of memory population phenotype CD4+CD45RO+ (A), CD8+CD45RO+ (B), memory T cell activation CD4+CD45RO+CD69+ (C), CD8+CD45RO+CD69+ (D), CD4+CD45RO+DR+ (E), CD8+CD45RO+DR+ (F), and memory T cell activation/exhaustion CD4+CD45RO+PD-1+ (G), CD8+CD45RO+PD-1+ (H) between cervical and peripheral blood T cells. p-values were determined by Wilcoxon matched pairs test.