Whole blood flow cytometric analysis of Ureaplasma-stimulated monocytes from pregnant women

- Vaginal colonisation with Ureaplasma spp. is common.
- Ureaplasma spp. are known to cause inflammation-driven preterm birth.
- Ureaplasma parvum stimulates monocyte cytokine response regardless of maternal colonisation.
- Ureaplasma spp. colonisation does not tolerise monocytes to subsequent stimulation.

We hypothesised that circulating monocytes of women with vaginal colonisation with Ureaplasma spp., genital microorganisms known to cause inflammation-driven preterm birth, would elicit a tolerised cytokine response to subsequent in vitro Ureaplasma parvum serovar 3 (UpSV3) stimulation. Using multi-parameter flow cytometry, we found no differences with regard to maternal colonisation status in the frequency of TNF-α-, IL-6-, IL-8- and IL-1β-expressing monocytes in response to subsequent UpSV3 stimulation (P > 0.10 for all cytokines). We conclude that vaginal Ureaplasma spp. colonisation does not specifically tolerise monocytes of pregnant women towards decreased responses to subsequent stimulation.