Bacterial vaginosis in pregnant adolescents: proinflammatory cytokine and bacterial sialidase profile. Cross-sectional study

ABSTRACT CONTEXT AND OBJECTIVE: Bacterial vaginosis occurs frequently in pregnancy and increases susceptibility to sexually transmitted infections (STI). Considering that adolescents are disproportionally affected by STI, the aim of this study was to evaluate the cervicovaginal levels of interleukin (IL)-1 beta, IL-6, IL-8 and bacterial sialidase in pregnant adolescents with bacterial vaginosis. DESIGN AND SETTING: Cross-sectional study at mother and child referral units in Belém, Pará, Brazil. METHODS: Vaginal samples from 168 pregnant adolescents enrolled were tested for trichomoniasis and candidiasis. Their vaginal microbiota was classified according to the Nugent criteria (1991) as normal, intermediate or bacterial vaginosis. Cervical infection due to Chlamydia trachomatisand Neisseria gonorrhoeae was also assessed. Cytokine and sialidase levels were measured, respectively, using enzyme-linked immunosorbent assays and MUAN conversion in cervicovaginal lavages. Forty-eight adolescents (28.6%) were excluded because they tested positive for some of the infections investigated. The remaining 120 adolescents were grouped according to vaginal flora type: normal (n = 68) or bacterial vaginosis (n = 52). Their cytokine and sialidase levels were compared between the groups using the Mann-Whitney test (P < 0.05). RESULTS: The pregnant adolescents with bacterial vaginosis had higher levels of IL-1 beta, IL-6 and IL-8 (P < 0.05). Sialidase was solely detected in 35 adolescents (67.2%) with bacterial vaginosis. CONCLUSIONS: Not only IL-1 beta and sialidase levels, but also IL-6 and IL-8 levels are higher in pregnant adolescents with bacterial vaginosis, thus indicating that this condition elicits a more pronounced inflammatory response in this population, which potentially increases vulnerability to STI acquisition.

【研究背景与目标】
细菌性阴道病（bacterial vaginosis）在妊娠人群中高发，且会提升性传播感染（sexually transmitted infections, STI）的易感性。鉴于青少年群体性传播感染的发病率显著偏高，本研究旨在评估合并细菌性阴道病的妊娠青少年的宫颈阴道白细胞介素（interleukin, IL）-1β、IL-6、IL-8及细菌唾液酸酶水平。

【研究设计与研究场所】
本研究为横断面研究，实施地点位于巴西帕拉州贝伦市的母婴转诊中心。

【研究方法】
本研究纳入168名妊娠青少年，采集其阴道样本检测滴虫病与念珠菌感染；依据1991年发布的努根特评分标准（Nugent criteria），将其阴道微生物群分为正常、中间型与细菌性阴道病三类。同时评估沙眼衣原体（Chlamydia trachomatis）与淋病奈瑟菌（Neisseria gonorrhoeae）所致的宫颈感染情况。采用酶联免疫吸附试验（enzyme-linked immunosorbent assays）与MUAN转化法，分别检测宫颈阴道灌洗液中的细胞因子与唾液酸酶水平。48名青少年（占纳入总人数的28.6%）因所检测的部分感染项目呈阳性被排除，剩余120名青少年按阴道菌群类型分为正常菌群组（n=68）与细菌性阴道病组（n=52）。采用曼-惠特尼U检验（Mann-Whitney test）对两组的细胞因子与唾液酸酶水平进行组间比较，检验水准设定为P<0.05。

【研究结果】
合并细菌性阴道病的妊娠青少年，其IL-1β、IL-6及IL-8水平均显著升高（P<0.05）。仅在35名（占细菌性阴道病组总人数的67.2%）合并细菌性阴道病的青少年中检测到唾液酸酶。

【研究结论】
合并细菌性阴道病的妊娠青少年不仅IL-1β与唾液酸酶水平升高，IL-6、IL-8水平同样升高，提示该病症可在该人群中引发更为显著的炎症反应，进而可能增加其感染性传播疾病的易感性。