Pathogenesis of abnormal vaginal bacterial flora

Area of Science:

• Microbiology and Immunology
• Vaginal Health and Gynecology

Background:

• Vaginal health is influenced by the lactobacillary flora, pH, and the presence of leukocytes.
• Cytokines play a role in inflammatory responses within the vaginal environment.

Purpose of the Study:

• To investigate the relationship between vaginal microscopy findings (lactobacillary grade, leukocytosis) and biochemical markers (pH, lactate, succinate, cytokines).
• To understand how these parameters change with alterations in vaginal flora composition and inflammatory status.

Main Methods:

• Vaginal fluid samples from 631 women were analyzed using wet mounts, pH measurement, and high vaginal swabs for culture.
• Lactate, succinate, and specific cytokine concentrations (IL-1β, IL-8, LIF, IL-1RA) were quantified.
• Statistical analyses included univariate and multivariate regression models.

Main Results:

• Disturbed lactobacillary flora correlated with increased Gardnerella vaginalis, Trichomonas vaginalis, enterococci, streptococci, and E. coli.
• Vaginal pH, IL-8, and IL-1β increased with worsening lactobacillary grade, while lactate decreased.
• Extreme leukocytosis led to a collapse in IL-1β and IL-1RA, with a sharp increase in LIF, differing from lactobacillary grade changes.

Conclusions:

• Vaginal leukocytosis and disturbed lactobacillary grade are linked to pH, lactate levels, and various cytokine concentrations.
• Cytokine levels generally increased linearly with the severity of leukocytosis or lactobacillary grade.
• In extreme inflammation, altered cytokine profiles (decreased IL-1β, increased LIF) suggest a mechanism to limit inflammatory damage.