Vaginal mucosal homeostatic response may determine pregnancy outcome in women with bacterial vaginosis a pilot study

Bacterial vaginosis (BV) is considered as a trigger for an inflammatory response that could promote adverse pregnancy outcome (APO). We hypothesized that BV-related inflammation could be counterbalanced by anti-inflammatory and mucosal homeostatic responses that could participate in pregnancy outcomes. A total of 402 vaginal self-samples from pregnant women in their first trimester were screened by Nugent score. In this population, we enrolled 23 pregnant women with BV but without APO, 5 pregnant women with BV and developing APO, 21 pregnant women with intermediate flora, and 28 random control samples from pregnant women without BV or APO. BV without APO in pregnant women was associated with 28-fold interleukin-8, 5-fold interleukin-10, and 40-fold interleukin-22 increases in expression compared to controls. BV associated with APO in pregnant women shared 4-fold increase in tumor necrosis factor, 100-fold decrease in interleukin-10, and no variation in interleukin-22 expressions compared to controls. Next-generation sequencing of vaginal microbiota revealed a shift from obligate anaerobic bacteria dominance in BV without APO pregnant women to Lactobacillus dominance microbiota in BV with APO. Our results show that the anti-inflammatory and mucosal homeostatic responses to BV may determine outcome of pregnancy in the setting of BV possibly through effects on the vaginal microbiota. (Medicine 95(5):e2668) Abbreviations: APO = adverse pregnancy outcome, BV = bacterial vaginosis, Ct = cycle threshold, DNA = deoxyribonucleic acid, GAPDH = glyceraldehyde 3-phosphate dehydrogenase, IF = intermediate flora, IL = interleukin, RNA = ribonucleic acid, TNF = tumor necrosis factor. INTRODUCTION B acterial vaginosis (BV) is a dysbiosis of the vaginal microbiota characterized by a shift from the normal Lactobacillus-dominant species to an increased abundance of anaerobic species and genital mycoplasmas. BV is a risk factor for Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, human papillomavirus, herpes simplex virus type-2, human immunodeficiency virus infection, pelvic inflammatory disease, and posthysterectomy wound infections in women of reproductive age. During pregnancy, while most BV remain clinically asymptomatic, the occurrence of BV before 13 completed weeks of amenorrhea increases the risk of adverse pregnancy outcomes (APOs) including preterm birth, spontaneous preterm labor, preterm prelabor rupture of membranes, recurrent abortion, or miscarriage. However, the pathophysiological mechanism through which BV affects the ongoing pregnancy remains unclear. To date, BV has only been considered as a trigger for an adverse inflammatory response during pregnancy. Indeed, an excess of proinflammatory cytokines during pregnancy is linked to APO. However, during pregnancy the immune balance is in favor of an anti-inflammatory/immunosuppressive state to tolerate foreign paternal antigens present in the fetus. Therefore, the interaction between the dysbiosis of BV and the specific anti-inflammatory balance of pregnancy might be involved. In other settings of mucosal microbiotal dysbiosis/immune interaction such as inflammatory bowel diseases, the critical immune responses involve proinflammatory cytokines, interleukin-17 (IL-17), interleukin-18 (IL-18), interleukin-6 (IL-6), interleukin-8 (IL8), interleukin-1b (IL-1b), tumor necrosis factor (TNF); mucosal wound repair cytokines such as interleukin-22 (IL-22); and anti-inflammatory cytokines such as interleukin-10 (IL-10). Therefore, in a pilot study of pregnant women with BV in their first trimester, we studied the relation between the vaginal mucosal immune balance and pregnancy outcome. Editor: Jessica Snowden. Received: September 1, 2015; revised: November 24, 2015; accepted: January 4, 2016. From the Faculty of Medicine of Lille, EA7366 Host-Pathogen Translational Research Group, University Lille North of France (EF, KF, EK, TG, RD); CHRU de Lille, Service de Maladies Infectieuses, Hôpital Claude Huriez (EF, KF, RD); University Lille, CHU Lille, IRCL, Structural and Functional Genomics Core Facility (MF, CV, RD); CHU Lille, Institut d’Immunologie—Centre de Biologie Pathologie et Génétique (SD, RD); UDSL, EA 2686, UFR Médecine (SD, RD); Univ Lille Nord de France (SD, BG, RD, DS); CHU Lille, Institut de Microbiologie, Laboratoire de Bactériologie Hygiène, Centre de Biologie Pathologie et Génétique (RD); UDSL, UFR Médecine (RD); CHU Lille, Service de Gestion du Risque Infectieux, des Vigilances et d’Infectiologie (BG); UDSL, EA 2694, UFR Médecine (BG, DS); Hôpital Saint Vincent, Service de GynécologieObstétrique (GB); CHU Lille, Service de Gynécologie-Obstétrique Hôpital Jeanne de Flandre (DS), Lille, France. Correspondence: Rodrigue Dessein, Institut de Microbiologie, Centre de Biologie Pathologie et Génétique, CHU Lille, F-59000 Lille, France; UDSL, UFR Médecine, F-59000 Lille, France; and Univ Lille Nord de France, F-59000 Lille, France (e-mail: rodrigue.dessein@chru-lille.fr). RD, DS, BG, KF, and GB conceived the study; EF, RD, SG, and SD performed the experiments; EF, RD, EK, DS, and SD wrote the first draft of the manuscript. All authors discussed the results and commented on the manuscript. The Ethical Committee of our institution approved the study was on December 20, 2011 (No. A0125437). PHRC 11-2011 of French Ministry of Health The authors have no conflicts of interest to disclose. Copyright # 2016 Wolters Kluwer Health, Inc. All rights reserved. This is an open access article distributed under the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ISSN: 0025-7974 DOI: 10.1097/MD.0000000000002668 Medicine®