Proposal of high dose intravenous immunoglobulin as a treatment for severe cases of tick-borne encephalitis

Background Arthropod-borne viral encephalitis of diverse origins shows similar clinical symptoms, histopathology and magnetic resonance imaging, indicating that the pathomechanisms may be similar. So far, there is no specific therapy for them. Vaccination remains the best prophylaxis against some of them. However, there are increasing numbers of case reports on the successful treatment of arboviral encephalitis with high dose intravenous immunoglobulins. Discussion To our knowledge, high dose intravenous immunoglobulin has not systematically been tried for the treatment of severe cases of tick-borne encephalitis. Antibody-dependent enhancement has been suspected, but not proven, in several juvenile cases of tick-borne encephalitis. Although antibody-dependent enhancement during secondary infection with dengue virus has been documented, no adverse effects were noticed in a controlled study of high dose intravenous immunoglobulin therapy for dengue-associated thrombocytopenia. The inflammationdampening therapeutic effects of generic high dose intravenous immunoglobulins may override the antibody-dependent enhancement effects potentially induced by cross-reactive antibodies or by virus-specific antibodies at sub-neutralizing levels. Summary In analogy to the increasing number of case reports on the successful treatment of other arboviral encephalitides with high dose intravenous immunoglobulins, it is proposed to treat also severe cases of tick-borne encephalitis with high dose intravenous immunoglobulins as early in the disease course as possible.