[Humoral immune response to structural and nonstructural proteins of tick-borne encephalitis virus in the natural history of the disease].

A hundred and ninety-one patients who had fallen ill with tick-borne encephalitis (TBE) after bites by virus-carrying ticks were examined to reveal the characteristics of antibody production of the major classes of immunoglobulins (IgM and IgG) against structural protein E of the TBE virus and nonstructural protein NS1 of the TBE viral replicative complex in the natural history of an infectious process in different forms and variants of the disease. In the two-wave course of TBE, the infectious process is characterized by a delayed antibody production, lower levels of specific antibodies against virion protein E in the acute phase of disease during the first wave of fever. The development of meningocerebral syndromes at the peak of the second fever wave is observed in patients with the delayed accumulation and low levels of IgG antibodies. Of great diagnostic and prognostic value is the detection of nonstructural protein NS1 antibodies on the first days of TBE, by taking into account the uncertainty of clinical criteria for the disease at its first (febrile) wave and the low titers (or their absence) of specific antibodies against virion protein E, detectable at that time in the sera of patient with the two-wave course of TBE.