Some features of the immune system response in the new coronavirus infection COVID-19

AIM: to study the cytokine link of immunity in patients with the new coronavirus infection COVID-19 and the possibility of using these data to predict the risk of lung tissue damage.

MATERIALS AND METHODS: Patients with diagnosed new coronavirus infection COVID-19 were divided into 4 groups depending on the severity of the disease: 1 — asymptomatic patients; 2 — patients with lung tissue damage in the amount of 25%; 3 — patients with lung tissue damage 50%; 4 — patients with lung tissue damage 75% (according to the results computed tomography). Immunological studies were performed upon admission to the clinic, then after 7 days and before discharge. The concentration of cytokines in blood serum was studied by the method of solid-phase enzyme immunoassay using kits manufactured by Vector Best.

RESULTS: In all groups, a low content of proinflammatory cytokines was found: tumor necrosis factor and interferon-γ, interleukin-1, interleukin-2. The median level of interleukin-6 in all groups during the entire follow-up period was within the normal range, however, in some patients there was a multiple excess of its concentration. In groups with 50% and 75% lung tissue damage, an increase in the concentration of interleukin-8 was shown. Statistically significant differences were noted only for the level of interleukin-8 between the group with an asymptomatic form of infection and the CT-2 and CT-3 groups. It was found that the concentration of interleukin-1 below 3.58 pg/ml is a significant risk factor for severe disease. In all groups of subjects, low levels of interleukin-4 and interleukin-10 were noted, while there was no significant difference between the groups. Positive correlations were revealed between the degree of lung tissue damage and the level of interleukins 6, 2 and 8. Negative correlations were established between the degree of lung tissue damage and the content of interleukin-1.

CONCLUSION: There was no significant activation of the cytokine link of adaptive antiviral immunity in the examined contingent. Serum cytokine levels were within normal values and had no significant intergroup differences. An increase in IL-8 in groups with clinically pronounced signs of infection indicates the activation of indicators characterizing innate immunity.