Immune homeostasis of a woman after the influenza in early pregnancy

A successful pregnancy requires an optimally tuned and well-regulated balance between immune activation and embryonic antigen tolerance. Natural killers NK lymphocytes play a key role in these processes. The objective: to study the characteristics of the immunity of pregnant women after influenza in the early stages of gestation on the basis of determining NK-cytotoxicity. Materials and methods. We examined 120 women who contracted influenza in the first trimester of pregnancy: the main group – 68 patients with placental dysfunction, the comparison group – 52 pregnant women without signs of placental insufficiency. The cytotoxicity of natural killers was assessed by flow cytometry. Statistical processing was performed using the methods of variation statistics (Mann-Whitney test and Fisher’s test) odds ratio (OR). Results. Women with placental insufficiency after influenza in early pregnancy are characterized by both increased and decreased NK-cytotoxicity, which increases the risk of placental insufficiency several times (from 2.87 to 5.03 per OR, depending on one indicator or a combination thereof). The factor “deviation from the norm of both indicators” has the greatest prognostic value (OR=5.03; 95% CI: 1.38–18.32; p<.05). At the same time, the increase, which indicates a high pro-inflammatory potential and potentially damaging effects of NK cells, has a higher prognostic value than the decrease: among women with placental insufficiency, the proportion with significantly higher levels of NK cytotoxicity was highest: 18 (26.5%) 5 (9.6%) patients of the comparison group (p<0.05). Conclusions. Excessive inflammatory response in combination with increased NK cytotoxicity, has a damaging effect on the endothelium, and reduced immune responses, causes a longer course of influenza and insufficient immune control of trophoblast invasion. That is, in pregnant women after influenza, transmitted in the early stages, there are violations of immune regulation, which when combined with possible violations of hormonal regulation, cause the formation of placental dysfunction and a high frequency of perinatal complications.