Viral pandemics have shown that infected pregnant women are at risk of adverse pregnancy outcomes. Current evidence suggests that a pregnant woman’s immune system undergoes a transformation necessary to maintain pregnancy and fetal growth. The prevalence of human papillomavirus (PVI) is high, and its role in adverse pregnancy outcomes and reproductive loss is highly controversial. About 90% of cases of persistent human papillomavirus infection (PVI) are eliminated within one to two years. The role of the immune system in the elimination and persistence of PVI has been proven; however, there is no clear understanding of the mechanisms whereby PVI infected cells escape immune surveillance up to the present day. In addition, the immune mechanisms underlying the PVI persistence constitute a pathogenetic basis for the development of mechanisms of infertility, miscarriage and pregnancy pathology. Genetic polymorphism of the mother and the developing fetus, persistent PVI types and microbial landscape are modulating factors with an unexplained contribution in the transformation of quantity of introduced influences into the qualitative change in the biological state. The foreign and Russian research results analysed by the authors show that timely and adequate therapy of PVI may contribute to the preservation of reproductive potential and prevention of obstetric losses. The modern approach to the treatment of persistent PVI suggests the use of antiviral and immunomodulatory therapy. Due to its immunomodulatory and antiviral properties, inosine pranobex is used to treat viral diseases such as PVI, herpes simplex viruses, cytomegalovirus, Epstein-Barr virus and influenza.

The endometrium has traditionally been considered sterile. Nowadays, active studies are performed on the female upper genital tract microbiota. Bacteria and/or viruses colonizing the endometrium are known to alter its functional properties, including receptivity and embryo implantation. Uterine cavity inflammation caused by microorganisms leads to disrupted cytokine expression, which, in turn, is mandatory for the successful implantation of the embryo. The present study assessed the vaginal and endometrial microbiota composition and its relation to the levels of cytokines produced by the endometrium in reproductive-aged women complaining of secondary infertility of unknown origin. The multiplex real-time PCR assay was applied for vaginal and endometrial microbiota analysis. The quantitative measurement of endometrial α-defensin (DEFa1), transforming growth factor (TGFβ1), and basic fibroblast growth factor (bFGF2) was carried out using the ELISA (Cloud-Clone Corporation (Katy, TX, USA; manufactured in Wuhan, China). A reliable decline in endometrial TGFβ1 and bFGF2 and an increase in DEFa1 were demonstrated in women with idiopathic infertility when compared to fertile patients. However, TGFβ1, bFGF2, and DEFa1 expression correlated reliably only with the presence of Peptostreptococcus spp. and HPV in the uterine cavity. The obtained results highlight the importance of local immune biomarker determination in the assessment of certain bacteria and viruses’ significance as causative agents of infertility.