Department of Epidemiology, Boston University School of Public Health, Boston, MA.
Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI.
Am J Obstet Gynecol. 2020 Sep;223(3):406.e1-406.e16. doi: 10.1016/j.ajog.2020.02.039. Epub 2020 Mar 2.
Vulvodynia (idiopathic vulvar pain) affects up to 8% of women by age 40 years, has a poorly understood etiology, and has variable treatment efficacy. Several risk factors are associated with vulvodynia from a history of yeast infections to depression and allergies. Recent work suggests an altered immune inflammatory mechanism plays a role in vulvodynia pathophysiology. Because the vaginal microbiome plays an important role in local immune-inflammatory responses, we evaluated the vaginal microbiome among women with vulvodynia compared with controls as 1 component of the immune system.
The objective of the study was to characterize the vaginal microbiome in women with clinically confirmed vulvodynia and age-matched controls and assess its overall association with vulvodynia and how it may serve to modify other factors that are associated with vulvodynia as well.
We conducted a case-control study of 234 Minneapolis/Saint Paul-area women with clinically confirmed vulvodynia and 234 age-matched controls clinically confirmed with no history of vulvar pain. All participants provided vulvovaginal swab samples for culture-based and non-culture (sequencing)-based microbiological assessments, background and medical history questionnaires on demographic characteristics, sexual and reproductive history, and history of psychosocial factors. Vaginal microbiome diversity was assessed using the Shannon alpha diversity Index. Data were analyzed using logistic regression.
Culture and molecular-based analyses of the vaginal microbiome showed few differences between cases and controls. However, among women with alpha diversity below the median (low), there was a strong association between increasing numbers of yeast infections and vulvodynia onset, relative to comparable time periods among controls (age-adjusted odds ratio, 8.1, 95% confidence interval, 2.9-22.7 in those with 5 or more yeast infections). Also among women with low-diversity microbiomes, we observed a strong association between moderate to severe childhood abuse, antecedent anxiety, depression, and high levels of rumination and vulvodynia with odds ratios from 1.83 to 2.81. These associations were not observed in women with high-diversity microbiomes.
Although there were no overall differences in microbiome profiles between cases and controls, vaginal microbiome diversity influenced associations between environmental and psychosocial risk factors and vulvodynia. However, it is unclear whether vaginal diversity modifies the association between the risk factors and vulvodynia or is altered as a consequence of the associations.
外阴痛（特发性外阴疼痛）影响多达 8%的 40 岁以下女性，其病因尚不清楚，治疗效果也各不相同。一些危险因素与外阴痛有关，从酵母菌感染史到抑郁和过敏。最近的工作表明，改变的免疫炎症机制在外阴痛病理生理学中起作用。由于阴道微生物组在局部免疫炎症反应中起着重要作用，我们评估了患有外阴痛的女性与对照组之间的阴道微生物组，将其作为免疫系统的一个组成部分。
本研究的目的是描述临床确诊为外阴痛的女性和年龄匹配的对照组的阴道微生物组，并评估其与外阴痛的总体相关性，以及它如何作为与外阴痛相关的其他因素的调节剂。
我们进行了一项病例对照研究，共纳入 234 名明尼阿波利斯/圣保罗地区临床确诊为外阴痛的女性和 234 名年龄匹配的临床确诊无外阴疼痛史的对照组。所有参与者均提供了阴道阴道拭子样本，用于基于培养和非培养（测序）的微生物学评估、人口统计学特征、性和生殖史以及心理社会因素的背景和医学史问卷调查。使用 Shannon alpha 多样性指数评估阴道微生物组多样性。使用逻辑回归分析数据。
基于培养和分子的阴道微生物组分析显示，病例和对照组之间几乎没有差异。然而，在多样性中位数以下的女性中，与对照组相比，酵母感染次数的增加与外阴痛的发病有很强的关联（年龄调整后的比值比，5 次或以上酵母感染者为 8.1，95%置信区间为 2.9-22.7）。在低多样性微生物组的女性中，我们还观察到中度至重度儿童期虐待、焦虑、抑郁和高水平反刍与外阴痛之间的强烈关联，比值比为 1.83 至 2.81。在高多样性微生物组的女性中没有观察到这些关联。
尽管病例和对照组之间的微生物组谱没有总体差异，但阴道微生物组的多样性影响了环境和心理社会风险因素与外阴痛之间的关联。然而，尚不清楚阴道多样性是否改变了危险因素与外阴痛之间的关联，或者是否因这些关联而改变。
