Aim to compare values of cytokines of interferon gamma (IFN-γ), interleukin 4 (IL-4) and their receptors (CD124 and CD 119) in newborns with severe HHV-6.

Methods 58 newborn infants with severe HHV-6 and 53 conditionally healthy newborn infants were examined.

The expression of membrane markers of immune competent cells CD119⁺, CD124⁺ in peripheral blood was determined using the flow laser cytofluorimeter “Beckman COULTER” Epics XL II (USA), (No. 20123). Lymphocyte typing was performed with the use of monoclonal antibodies to differentiation clusters CD119⁺, CD124⁺ made by IMMUNOTECH (France). The level of IFN-γ and IL-4 in blood serum was determined by ELISA technique with eBioscience (USA) test systems.

Results The content of IL-4 in newborn infants with severe HHV-6 at the age of 1 month is significantly higher as compared with the control group [5.5(5.0–7.2) pg/ml and 4.4(3.6–4.8) pg/ml], (p < 0.05).

Interferon-γ level had a significant decrease in newborn infants with severe HHV-6 as compared with the control group [3.05(2.8–3.21) pg/ml and 3.95 (3.4–5.3 pg/ml) respectively], (p < 0,000019).

In case of severe HHV-6, there was an increase in the level of IL-4 receptors (CD124) as compared with the control group [4.2(2.9–5.5)% and 0.6 (0.2–1.1)% respectively] (p < 0.000019) and a decrease in the level of IFN-γ receptors (CD119) by 2.6 times [0.9(0.68–1.24)% and 2.4 (2.2–2.8)]% respectively (p < 0.000004).

Conclusions The increased production of IL-4 is caused by the induction of its synthesis by herpes virus of type 6 determining IL-4 value in the inductive phase of the immune response. Decrease in the level of expression of CD119 in the group of newborn infants with severe HHV-6 at the age of 1 month indicates that the sensitivity of lymphoid cells to IFN-γ in this group of newborn infants was not sufficiently formed, and this in the combination with the low level of IFN-γ production causes a severe course of the disease.