O-261 The relationship of abnormal vaginal microbiome (dysbiosis of vaginal microbiome) and proinflammatory cytokines in recurrent implantation failure patients

Abstract Study question Is there any correlation between serum cytokine levels and the composition of vaginal microbiome in recurrent implantation failure (RIF) patients? Summary answer The IFN-γ/IL-10 TNF-α/IL-6 ratios are higher patients with dysbiotic which associates an imbalance towards inflammation Th1/Th2 lymphocytes. What is known already In recent years, development sequencing-based technologies has enabled evaluation microbiome. Studies have shown that a microbiota less than 90% Lactobacillus predictive IVF treatment outcome suggests dysbiosis reproductive tract negatively affects compared to women Lactobacillus-dominated Furthermore, it pregnancy characterized by Th2-dominant pattern, and, contrast, altered ratio, NK cell macrophage numbers more prevalent RIF. design, size, duration Twenty were included retrospective study December 2018 May 2022. Thirteen had normal seven all them, sample was analyzed cytokines IL-2, IL-4, IL- 6, IL-8, IL-10, VEGF, IFNγ, TNFα, IL-1α, IL-1β, MCP-1 EGF measured. Patients uterine malformations, surgery or other factors may influence RIF excluded from analysis. Participants/materials, setting, methods To measure different cytokines, sandwich immunoassay specific antibodies for IL-6, IL -1α, used. Vaginal mass sequencing V3V4 region 16S rRNA. statistical analysis performed R Statistical Software, version 4.0.3 bioinformatic using QIIME2 MicrobiomeAnalyst packages. Main results role chance For produced Th1 lymphocytes Th2 lymphocytes, we observe (p = 0,043) 0,021) microbiome, inflammation. Comparing respect alpha diversity, no differences observed either individually cytokines. However, multivariate model predicts diversity 0.037; AIC=20.734) does consider aforementioned ratios. Alpha turn, samples 0.003). Regarding beta also 0.007). Considering relative abundance each bacteria, can predict ratios: reaches 91.37% prediction including Burkholderia, Chryseobacterium, Enterococcus, Escherichia, Gemella, Herbaspirillum, Negativicoccus Staphylococcus. 87,65% Aerococcus, Megasphera, Pseudomonas, Ralstonia It worth noting absence these models, some pathogenic bacteria what alter production not lower Lactobacillus. Limitations, reasons caution inherent limitations design limited size. addition, measured fluid. Additional studies metagenomic approach might be able determine functional groups Wider implications findings These indicate such as Burkholderia Staphilococcus, modify cause inflammation, induce ratio. When altered, administration antibiotics probiotics improve immunologic environment, thus, avoiding use immunosuppressants. Trial registration number -