Use of Intravaginal Cooling to Provide Symptom Relief in Women With Vulvovaginal Candidiasis and Reduce Immunopathology in an Accompanying Mouse Model

Abstract

Background: Vulvovaginal candidiasis (VVC), caused primarily by Candida albicans, is treated with anti-fungal drugs, often with variable efficacy and relapses. New therapeutic strategies, including drug-free alternatives, are needed. Upon overgrowth or environmental triggers, C. albicans commensal yeast transitions into hyphae resulting in an aberrant immunopathologic neutrophil response that contributes to the characteristic signs and symptoms of vaginitis. The purpose of this study was to evaluate the efficacy of an intravaginal cooling device (Vlisse) in women with VVC to provide symptom relief via putative reversal of C. albicans hyphae to yeast, with additional proof of principle in an animal model.

Methods: Five women with VVC were instructed to use the device twice daily for 3 days. Vulvovaginal symptoms were monitored and scored for each use, followed by pelvic examination at 30 days. A mouse model of VVC employed cooled micro stir rods to evaluate the cooling effect on fungal morphology and vaginal immunopathology.

Results: Clinical cure was achieved in all women. In the mouse model, the insertion of pre-cooled magnetic rods intravaginally for short periods over 3 days, reduced the immunopathogenic neutrophil infiltration and hyphae.

Conclusions: Intravaginal cooling provides clinical cure for VVC and proof of principle in an animal model.

Keywords: Candida albicans; hyphae; inflammation; non-pharmacologic therapies; vulvovaginal candidiasis.

Figure 1.

Effects of intravaginal cooling treatment in women with moderate to severe vulvovaginal candidiasis (VVC). Five women were enrolled in the clinical trial study based on eligibility/exclusion criteria. For assessment of vulvovaginal signs and symptoms (itching, burning, pain, dysuria, swelling, redness and discharge) at baseline and subsequent time points, a scoring system was used for quantitative evaluation on a scale of 0–4 as a measure of the severity of vaginitis: 0, none; 1, minimal; 2, mild; 3, moderate; or 4, severe. The standard treatment regimen consisted of 30-minute vaginal cooling sessions twice daily, approximately 12 hours apart, for 3 days, totaling 6 individual treatment sessions. The participants self-assessed and recorded their vaginal signs and symptoms before and after treatment for each use, followed by a follow-up pelvic examination conducted 30 days after treatment. A, Scores per symptom category from baseline to after treatment assessed at each use. B, Composite symptom scores per participant from baseline to after treatment assessed at each use. Horizontal dotted line represents the threshold for composite symptom scores (≥7), defined as moderate to severe VVC. C, Composite symptom scores per use at baseline and before and after treatment. Dot plot (A), bar heights (C) and error bars (A and C) reflect the mean ± SEM of the values computed from the 5 patients. Data were analyzed using the repeated-measures analysis of variance (ANOVA) comparing change over successive treatments (A), the 2-way ANOVA followed by the Bonferroni posthoc test comparisons between patients (B), or the 1-way ANOVA followed by the unpaired Student t test comparing the baseline/pretreatment and each posttreatment value (**P < .01; ***P < .001), comparing the posttreatment and the next pretreatment interval between treatments (^##P < .01; ^###P < .001), or comparing the baseline and each pretreatment value (^P < .05; ^^P < .01; ^^^P < .001) (C). Abbreviations: ND, not detected; NS, not significant.

Figure 2.

Effects of cooling treatment on presence of Candida albicans hyphae during experimental vaginitis. Estrogen-treated mice were intravaginally inoculated with C. albicans 96113. Four days after inoculation, mice were treated intravaginally with sterile magnetic micro rods prewarmed to 35°C or precooled to −20°C for a period of 40 minutes total (4 successive 10-minute treatment applications), twice daily for 3 days; mice in the control group remained untreated. Vaginal lavage fluid was collected on day 0 (2 days after inoculation, before treatment) and 1–3 days after the final treatment, on days 4 and 6 of the study period. A, Temperature shifts in the vaginal cavities of inoculated mice before and after treatment. B, Vaginal fungal burden before (day 0) and after (days 4–6) treatment, assessed by quantitative plate counts. C, Quantification of C. albicans hyphal scores by means of wet mount microscopy of the vaginal lavage samples, using the following scoring system; 0, no hyphae; 1, sparse hyphae; 2, small amounts of hyphae present in several fields; 3, large amounts of hyphae in several fields; or 4, masses of hyphae in most fields. A, C, Lines (A), bar heights (C) and error bars reflect group means ± SEM of the values computed from independent replicates of each of 4 unique sets of animals, with 2–6 mice per group. B, Dot plots represent data points for unique animals from 5 independent experiments, each including 2–6 mice per group. Data were analyzed using 2-way ANOVA comparing repeated measures between the 3 treatment groups followed by Bonferroni posthoc tests at the end point (A), Kruskal-Wallis test between groups at each time point (B), or unpaired Student t test to compare among groups at each time point or between each group at different time points (C). **P < .01; ***P < .001. Abbreviation: CFUs, colony-forming units.

Figure 3.

Effects of cooling treatment on vaginal inflammation during experimental vaginitis. Estrogen-treated mice were intravaginally inoculated with Candida albicans 96113. Two days after inoculation, mice either remained untreated or were treated intravaginally with sterile magnetic rods prewarmed to 35°C or precooled to −20°C for a treatment period of 40 minutes total (4 successive applications of 10-minute treatment), twice daily for 3 days. Vaginal lavage fluid was collected on day 0 (2 days after inoculation; before treatment) and 1–3 days after the final treatment, on days 4 and 6 of the study period. Vaginal cellular infiltrates were stained using the Papanicolaou technique and examined using light microscopy at ×400 magnification. The number of polymorphonuclear neutrophils (PMNs) was quantified in 5 nonadjacent fields per sample and averaged. Bar heights and error bars reflect the group mean ± SEM of the values computed from independent replicates of each of 5 unique sets of animals, with 2–6 mice per group. Data were analyzed using 1-way ANOVA, followed by Tukey posthoc tests and the Student t test to compare groups at each time point or between each group at different time points, respectively. *P < .05; **P < .01.