Interleukin-1β in peripheral blood of pregnant women with mild and moderate course of acute SARS-CoV-2 infection

Pregnant women are susceptible to SARS-CoV-2 infection due to physiological features of the immune system. The aim of our study was to evaluate the levels of interleukin-1β (IL-1β) in peripheral blood of pregnant women during SARS-CoV-2 infection with mild to moderate forms of the disease. We examined 60 pregnant women with COVID-19, including 14 women in the 1st trimester, 17 in the 2nd trimester, and 29 in the 3rd trimester. The comparison group consisted of 20 pregnant women without clinical and laboratory signs of acute respiratory infections. IL-1β concentrations were determined in serum using ELISA technique. Statistica 10.0 (StatSoft, USA) was used for statistical data processing. The significant error level was considered to be p < 0.05. The study results showed higher levels of IL-1β in blood of SARS-CoV-2-infected pregnant women compared to pregnant women without clinical and laboratory evidence of acute respiratory infections (p = 0.005). COVID-19 is characterized by a decreased IL-1β level in blood during the 3rd trimester of gestation as compared to the 1st trimester (p = 0.01). Pregnant women with COVID-19, compared with pregnant women without detectable signs of acute respiratory infections, had higher levels of red blood cells (p = 0.043), total protein (p = 0.006), direct bilirubin (p = 0.02), high-sensitivity C-reactive protein (p < 0.001), ferritin (p = 0.016), prothrombin time (p = 0.018) and blood clotting INR values (p = 0.013). COVID-19 in pregnant women is associated with lower levels of lymphocytes (p = 0.004), serum iron (p < 0.001) and transferrin (p = 0.003), transferrin saturation coefficient (p = 0.026) and total iron-binding capacity of blood serum (p = 0.021). IL-1β in SARS-CoV-2-infected pregnant women had an inverse correlation with biochemical and coagulation blood parameters: transferrin (p = 0.006), total iron-binding capacity of serum (p = 0.03), latent iron-binding capacity of serum (p = 0.009), fibrinogen (p = 0.002). IL-1β in the blood of SARS-CoV-2-infected pregnant women is associated with the level of direct bilirubin (p = 0.045) in moderate COVID-19, C-reactive protein (p = 0.047) and alanine aminotransferase (p = 0.024) in mild forms of the disease. Moderate COVID-19 in pregnant women is associated with a decreased leukocyte counts (p = 0.038), and an increase in prothrombin time (p = 0.046). Thus, a relationship was established between the concentration of IL-1β in blood, blood coagulation and biochemical parameters in women with COVID-19 at different stages of pregnancy, as well as dependence on the clinical severity of COVID-19.