The effect of the course of pregnancy on vaginal microbiocenosis and development of atopia in children born to mothers with bronchial asthma
Authors:   V.A.Almazov National Medical Research Centre, Saint Petersburg, Russian Federation, Kosenkova T.V. , Novikova V.P. ,   Saint Petersburg State Paediatric Medical University, Saint Petersburg, Russian Federation, Boytsova E.A. ,   V.A.Almazov National Medical Research Centre, Saint Petersburg, Russian Federation, Zazerskaya I.E. ,   V.A.Almazov National Medical Research Centre, Saint Petersburg, Russian Federation, Lavrova O.V. ,   Academician I.P.Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russian Federation, Gurina O.P. ,   Saint Petersburg State Paediatric Medical University, Saint Petersburg, Russian Federation, Blinov A.E. ,   Saint Petersburg State Paediatric Medical University, Saint Petersburg, Russian Federation, Varlamova O.N. ,   Saint Petersburg State Paediatric Medical University, Saint Petersburg, Russian Federation, Boldyreva M.N. ,   National Research Centre Institute of Immunology, Federal Medico-Biological Agency of Russia, Moscow, Russian Federation, Khavkin A.I. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation
Published: May 2021

The aim of the work was to study the characteristics of vaginal microbiota in women suffering from bronchial asthma, depending on the specific features of the course of pregnancy and to determine the levels of umbilical cord blood cytokines in children born to such mothers in order to identify the epigenetic factors contributing to early realization of the atopic phenotype. Patients and methods. 37 pregnant woman-baby pairs were examined. The main group included pregnant women suffering from bronchial asthma. The comparison group consisted of 24 healthy pregnant woman-baby pairs. Cord blood cytokines were studied in newborns. The quantitative and qualitative assessment of vaginal flora was carried out by the polymerase chain reaction (PCR) method. In the examined samples, control material samples (CMS) were tested, total bacterial mass (TBM), absolute counts of microorganisms were determined, followed by calculation of relative values. Also, the relative quantitative indicators of microbiota were calculated, reflecting the ratio of the number of specific microorganisms to total bacterial mass. Umbilical cord blood samples were examined for cytokines (TGF-β1, IL-10, IL-13 and IFN-γ) by ELISA in 15 babies of the main group and 24 babies of the comparison group. Discussion and conclusions. The studies conducted are demonstrative of the fact that certain features of the course of pregnancy such as threatened miscarriage or preeclampsia are the factors affecting the composition of vaginal microbiota of a pregnant woman. A shift in the ratio of the main microaerophilic bacteria of vaginal secretion toward Gardnerella vaginalis and a decrease of Lactobacillus sp. might impair the development of fetal and infant intestinal microbiocenosis. At the same time, the microbiota of the newborn is similar to that of the mother and is closest to vaginal microbiota. Normally, it is characterized by predominance of such microorganisms as Bifidobacterium longum and Bifidobacterium infantis, Bacteroidetes, Lactobacillus sp., Prevotella, Atopobium, which determine the direction of the immune response and the formation of tolerance in infancy. Conclusion. Changes in vaginal microbiota and intestinal microbiocenosis of a baby might become the epigenetic factor that triggers allergic inflammation even in utero, as evidenced by the imbalance of the main pro and anti-inflammatory cytokines (IL-13 and IL-10), the increased contents of which in the umbilical cord blood reflect the systemic response of the body to tissue and organ damage, and serves as one of the indicators of the intensity and duration of prenatal allergic inflammation, as well as progression of the disease. Higher levels of IL-13 and IL-10 in the umbilical cord blood might be regarded as a marker of the intrauterine onset of allergic inflammation in children with an allergic family history. Key words: allergy, pregnancy, vaginal microbiota, children, cytokines